US20160103397A1 - Exposure Apparatus with Component from which Liquid is Protected and/or Removed and Device Fabricating Method - Google Patents

Abstract

An exposure apparatus exposes a substrate by filling a liquid between a projection optical system and the substrate, and projecting the image of a pattern onto the substrate through the projection optical system and the liquid, and includes a liquid removing mechanism that intermittently blows a gas against a reference member, movable mirror, and the like, to which the liquid is adhered in order to remove that liquid.

Description

CROSS-REFERENCE TO RELATED APPLICATION
• This is a Continuation of U.S. application Ser. No. 11/360,807, filed on Feb. 24, 2006, which in turn is a Continuation of International Application No. PCT/JP2004/012795, filed Aug. 27, 2004, which claims priority to Japanese Patent Application No. 2003-307025 (filed Aug. 29, 2003). The contents of the aforementioned application are incorporated herein by reference.
BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention relates to an exposure apparatus, which exposes a pattern on a substrate through a projection optical system and a liquid, and a device fabricating method.
• 2. Description of Related Art
• Semiconductor devices and liquid crystal display devices are fabricated by a so-called photolithography technique, wherein a pattern formed on a mask is transferred onto a photosensitive substrate. An exposure apparatus used by this photolithographic process includes a mask stage that supports the mask, and a substrate stage that supports the substrate, and transfers the pattern of the mask onto the substrate via a projection optical system while successively moving the mask stage and the substrate stage. There has been demand in recent years for higher resolution projection optical system in order to handle the much higher levels of integration of device patterns. The shorter the exposure wavelength used and the larger the numerical aperture of the projection optical system, the higher the resolution of the projection optical system. Consequently, the exposure wavelength used in exposure apparatus has shortened year by year, and the numerical aperture of projection optical systems has also increased. Furthermore, the mainstream exposure wavelength currently is 248 nm KrF excimer laser, but an even shorter wavelength 193 nm ArF excimer is also being commercialized. In addition, as well as resolution, the depth of focus (DOF) is also important when performing an exposure. The following equations respectively express the resolution R and the depth of focus .delta. R=k.sub.1.lamda./NA, (1) .delta.=.+−.k.sub.2.lamda./NA.sup.2, (2)
• Therein, .lamda. is the exposure wavelength, NA is the numerical aperture of the projection optical system, and k.sub.1 and k.sub.2 are the process coefficient. Equations (1) and (2) teach that if the exposure wavelength .lamda. is shortened and the numerical aperture NA is increased in order to enhance the resolution R, then the depth of focus .delta. narrows.
• If the depth of focus .delta. becomes excessively narrow, then it will become difficult to align the surface of the substrate with the image plane of the projection optical system, and there will be a risk of insufficient margin of focus during the exposure operation. Accordingly, a liquid immersion method has been proposed, as disclosed in, for example, PCT International Publication WO99/49504 below, as a method to substantially shorten the exposure wavelength and increase the depth of focus. This liquid immersion method fills a liquid, such as water or an organic solvent, between the lower surface of the projection optical system and the surface of the substrate, thus taking advantage of the fact that the wavelength of the exposure light in a liquid is 1/n that of in air (where n is the refractive index of the liquid, normally about 1.2 to 1.6), thereby improving the resolution as well as increasing the depth of focus by approximately n times. The contents of the abovementioned international publication is hereby incorporated by reference in its entirety to the extent permitted by the national laws and regulations of the designated status (or elected states) designated by the present international patent application.
• Incidentally, the abovementioned related art has the problems discussed below.
• The exposure apparatus disclosed in the abovementioned PCT International Publication No. WO99/49504 has a constitution wherein the liquid is supplied and recovered so that an immersion area is formed on one part of the substrate; however, if, in a state after the immersion exposure is completed and the liquid in the immersion areas is not sufficiently recovered, the substrate stage, for example, is moved to a load/unload position (substrate exchange position) in order to unload the substrate on the substrate stage and load a new substrate, then there is a possibility that the liquid remaining (adhered) on the front of the projection optical system, or in the liquid supply nozzle, the recovery nozzle, or the like, may drop onto peripheral devices, for example, the guide surface of the stage, the reflecting mirror for the stage interferometer, and the like.
• In addition, if liquid remains on the optical element at the front of the projection optical system, then there is a possibility that adhered residue (a so-called water mark) will be left on the optical element at the front of the projection optical system after this remaining liquid has vaporized, and will adversely affect the pattern formed on the substrate when performing the next exposure process. In addition, it is conceivable that immersion areas will form, even when not performing the exposure process, when using a reference plane member, a fiducial mark member, and the like, disposed around the substrate on the substrate stage, and there is a possibility that the liquid in these immersion areas will not be sufficiently recovered and that adhered residue will be left on these members, or that the liquid remaining on these members will scatter.
• Furthermore, it is also conceivable that the liquid from the immersion area on the substrate during exposure will scatter and adhere to peripheral apparatuses, members, and the like. If the liquid scattered from the substrate during exposure adheres to, for example, the reflecting mirror for each of the stage interferometers, then there is a risk that it will degrade the accuracy of the stage position measured by the interferometer.
SUMMARY OF THE INVENTION
• The present invention was made considering such circumstances, and it is an object of the present invention to provide an exposure apparatus that can sufficiently remove and/or recover unnecessary liquid and form a desired device pattern on the substrate when projecting and exposing a pattern onto a substrate through a projection optical system and liquid, and a device fabricating method that uses this exposure apparatus.
• To solve the abovementioned problems, the present invention adopts the following constitution corresponding toFIGS. 1 to 22, which describe the embodiments. Furthermore, to facilitate understanding, the present invention will be explained using the corresponding symbols in drawings that describe one embodiment, but the present invention is not limited to this embodiment.
• The exposure apparatus of the present invention is an exposure apparatus that exposes a substrate by filling a liquid between a projection optical system and the substrate, and projecting the image of a pattern onto the substrate through the projection optical system and the liquid, including a liquid removing mechanism that intermittently blows a gas against a component to which the liquid is adhered in order to remove that liquid, the component disposed in a vicinity of the image plane of the projection optical system.
• In addition, the exposure apparatus of the present invention is an exposure apparatus that exposes a substrate by filling a liquid between a projection optical system and the substrate, and projecting the image of a pattern onto the substrate through the projection optical system and the liquid, including: a liquid removing mechanism that blows a gas against a component to which the liquid is adhered in order to remove that liquid, the component disposed in a vicinity of the image plane of the projection optical system; wherein, the liquid removing mechanism blows the gas while changing a flow speed thereof.
• According to the present invention, it is possible to form a turbulent flow on the surface of the components by blowing the gas, either intermittently or while varying the flow speed thereof, against the components, which are disposed in the vicinity of the image plane of the projection optical system, thereby satisfactorily removing unnecessary liquid adhering to the components. Accordingly, it is possible to prevent the dropping, scattering, and the like, of the liquid from the components, and the occurrence of adhered residue (water mark) on these components, thereby forming a desired pattern on the substrate with good accuracy.
• The exposure apparatus of the present invention is an exposure apparatus that exposes a substrate by filling a liquid between a projection optical system and the substrate, and projecting the image of a pattern onto the substrate through the projection optical system and the liquid, including: a liquid removing mechanism having a vibrating apparatus that vibrates a component in order to remove the liquid adhering to the component, the component disposed in a vicinity of the image plane of the projection optical system.
• According to the present invention, vibrating the components, which are disposed in the vicinity of the image plane of the projection optical system, promotes the removal of liquid adhering to the components, and enables the satisfactory removal of unnecessary liquid. Accordingly, it is possible to prevent the dropping, scattering, and the like, of the liquid from the components, and the occurrence of adhered residue (water mark) on these components, thereby forming a desired pattern on the substrate with good accuracy.
• The exposure apparatus of the present invention is an exposure apparatus that exposes a substrate by filling a liquid between a projection optical system and the substrate, and projecting the image of a pattern onto the substrate through the projection optical system and the liquid, including: a liquid removing mechanism that removes the liquid that scattered from the substrate during exposure and adhered to a component disposed in a vicinity of the image plane of the projection optical system.
• According to the present invention, it is possible, even if the liquid scatters from the substrate to the periphery during immersion exposure, to prevent the problem of reduced exposure accuracy caused by the scattered liquid, and to form the desired pattern on the substrate with good accuracy by removing that scattered liquid.
• The exposure apparatus of the present invention is an exposure apparatus that exposes a substrate by filling a liquid between a projection optical system and the substrate, and projecting the image of a pattern onto the substrate through the projection optical system and the liquid, including: a liquid removing mechanism that removes the liquid adhering to the component in parallel with the operation of exposing the substrate, the component disposed in a vicinity of the image plane of the projection optical system.
• According to the present invention, it is possible, even if liquid from the substrate scatters and adheres to the components during immersion exposure, to remove the liquid, without reducing the throughput of the entire exposure process, by performing the operation of removing the liquid adhering to the components in parallel with the exposure operation. Furthermore, by removing the liquid adhering to the components, it is possible to prevent the problem of reduced exposure accuracy caused by the adhered liquid, and to form the desired pattern on the substrate with good accuracy.
• The exposure apparatus of the present invention is an exposure apparatus that exposes a substrate by filling a liquid between a projection optical system and the substrate, and projecting the image of a pattern onto the substrate through the projection optical system and the liquid, including: a shield member provided on the upper side of a component, that prevents the adherence of the liquid to the component, said component disposed in a vicinity of the image plane of the projection optical system.
• According to the present invention, either during the exposure or after (or before) the completion of the exposure of the substrate, the shield member can block the liquid that scattered from the substrate, the liquid that dropped from parts, such as the nozzle, and the like, and it is therefore possible to prevent the problem wherein the liquid adheres to the component that is on the lower side of that shield member. Accordingly, it is possible to prevent the problem of reduced exposure accuracy caused by the liquid adhering to the component, and to form the desired pattern on the substrate with good accuracy.
• The exposure apparatus of the present invention is an exposure apparatus that exposes a substrate by filling a liquid between a projection optical system and the substrate, and projecting the image of a pattern onto the substrate through the projection optical system and the liquid, including: a stage that has a holding surface, which holds the substrate, and that is capable of moving with respect to the projection optical system; and a liquid receiving member, which is disposed around the stage, that is set so that the liquid receiving surface is positioned lower than the holding surface.
• According to the present invention, the liquid receiving member can receive the liquid that dropped from the end part of the stage, the liquid that dropped from the optical element disposed at the front of the projection optical system and from the lens cell that holds this optical element, and the like, and it is consequently possible to prevent the adherence and scattering of the liquid to locations where the adherence of the liquid is undesirable, such as the drive part of the stage, the base, and the like. Consequently, it is possible to suppress a reduction in the positioning accuracy of the substrate, and to form the desired pattern on the substrate with good accuracy.
• The exposure apparatus of the present invention is an exposure apparatus that exposes a substrate by projecting an image onto the substrate through a liquid, which is supplied to the substrate, including: a stage that is capable of holding and moving the substrate; a position detection member, which is provided to the stage, for detecting information related to a position of the stage; and a liquid removing mechanism that removes the liquid adhering to the position detection member.
• According to the present invention, it is possible to remove the liquid adhering to the position detection member (e.g., the movable mirror that reflects a measurement beam from the laser interferometer), for detecting information related to the position of the stage, and it is consequently possible to suppress an adverse impact on the measurement of the position of the stage and on the positioning accuracy of the substrate, and to form the desired pattern on the substrate with good accuracy.
• The exposure apparatus of the present invention is an exposure apparatus that exposes a substrate by forming an immersion area of liquid on a substrate and projecting an image on the substrate through the liquid of the immersion area, including: a stage apparatus that is capable of holding and moving the substrate; an interferometer that detects a position information of the stage apparatus; and a reflecting surface, which is provided to the stage apparatus, that reflects the measurement beam from the interferometer; wherein, the upper end of the reflecting surface is positioned lower than the immersion area.
• The exposure apparatus of the present invention is an exposure apparatus that exposes a substrate by projecting an image on the substrate through a liquid, which is supplied to the substrate, including a substrate holding member that is capable of holding and moving the substrate; an interferometer that detects a position information of the substrate holding member; a plate shaped member, which is installed on the upper surface of the substrate holding member, that is liquid repellant; and a reflecting surface, which is provided to the substrate holding member below the plate shaped member, that reflects the measurement beam from the interferometer; wherein, at least one part of the end part of the plate shaped member protrudes, in the direction in which the measurement beam impinges the reflecting surface, on the incident direction side more than the reflecting surface.
• The exposure apparatus of the present invention is an exposure apparatus that forms an image on a substrate by a projection optical system, including: a substrate holding member that is capable of holding and moving, at least within a plane, the substrate; an interferometer that detects a possible information of the substrate holding member within the plane; and a reflecting surface, which is provided to the substrate holding member, that reflects the measurement beam from the interferometer; wherein, at least part of the optical path of the measurement beam which impinges the reflecting surface, passes below at least part of the substrate holding member.
• A device fabricating method of the present invention uses the exposure apparatus as recited above. According to the present invention, it is possible to fabricate devices having a desired performance in a state wherein environmental changes, the occurrence of residue adhering to the optical element in a vicinity of the image plane of the projection optical system, and the like, are suppressed.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a schematic block diagram showing one embodiment of an exposure apparatus of the present invention.
• FIG. 2 is a schematic block diagram showing a liquid supply mechanism and a liquid recovery mechanism for forming an immersion area.
• FIG. 3 is a plan view showing a substrate stage.
• FIG. 4 shows one example of a stage liquid recovery apparatus.
• FIG. 5A andFIG. 5B are schematic views showing one example of a first liquid removing apparatus, which is a liquid removing mechanism.
• FIG. 6 is a schematic view showing one example of the operation of a second liquid removing apparatus, which is a liquid removing mechanism.
• FIG. 7A andFIG. 7B are schematic drawings for explaining the operation of blowing gas.
• FIG. 8 is a schematic view showing one example of the operation of the second liquid removing apparatus, which is a liquid removing mechanism.
• FIG. 9 shows another embodiment of a vibrating apparatus.
• FIG. 10 is a schematic view showing another example of the second liquid removing apparatus, which is a liquid removing mechanism.
• FIG. 11 is a schematic view showing another example of a second liquid removing apparatus, which is a liquid removing mechanism.
• FIG. 12 shows another embodiment of the vibrating apparatus.
• FIG. 13 is a schematic view showing another example of the first liquid removing apparatus, which is a liquid removing mechanism.
• FIG. 14 is a schematic view showing another example of the first liquid removing apparatus, which is a liquid removing mechanism.
• FIG. 15 is a schematic view showing another example of the first liquid removing apparatus, which is a liquid removing mechanism.
• FIG. 16 is a schematic view showing one example of a third liquid removing apparatus, which is a liquid removing mechanism.
• FIG. 17 is a schematic view showing another example of the third liquid removing apparatus, which is a liquid removing mechanism.
• FIG. 18 is a schematic view showing another example of the third liquid removing apparatus, which is a liquid removing mechanism.
• FIG. 19 is a schematic view showing another example of the third liquid removing apparatus, which is a liquid removing mechanism.
• FIG. 20 is a schematic view showing another example of the second liquid removing apparatus, which is a liquid removing mechanism.
• FIG. 21 is a schematic view showing an aspect wherein a shield member is provided on the upper side of a movable mirror.
• FIG. 22 is a flowchart showing one example of the process for manufacturing a semiconductor device.
DETAILED DESCRIPTION OF THE INVENTION
• The following explains the exposure apparatus of the present invention, referencing the drawings.FIG. 1 is a schematic block diagram that depicts one embodiment of the exposure apparatus according to the present invention.
• InFIG. 1, the exposure apparatus EX includes: a mask stage MST that supports a mask M; a substrate stage PST that supports a substrate P; an illumination optical system IL that illuminates with an exposure light EL the mask M supported by the mask stage MST; a projection optical system PL that projects and exposes a pattern image of the mask M illuminated by the exposure light EL onto the substrate P supported by the substrate stage PST; and a control apparatus CONT that provides overall control of the operation of the entire exposure apparatus EX. The entire exposure apparatus EX is housed within a chamber apparatus CH.
• The exposure apparatus EX of the present embodiment is a liquid immersion type exposure apparatus that applies the liquid immersion method to substantially shorten the exposure wavelength, improve the resolution, as well as substantially increase the depth of focus, and includes aliquid supply mechanism10 that supplies aliquid1 to the substrate P, and aliquid recovery mechanism20 that recovers theliquid1 on the substrate P. In the present embodiment, pure water is used as theliquid1. At least during the transfer of the pattern image of the mask M onto the substrate P, the exposure apparatus EX forms the immersion area AR2 with theliquid1, which is supplied by theliquid supply mechanism10, in at least one part on the substrate P that includes a projection area AR1 of the projection optical system PL. Specifically, the exposure apparatus EX exposes the substrate P by filling theliquid1 between anoptical element2 at the front part of the projection optical system PL and the surface (exposure surface) of the substrate P, and then projecting the pattern image of the mask M onto the substrate P through the liquid1 that is between this projection optical system PL and the substrate P, and through the projection optical system PL.
• The present embodiment will now be explained as exemplified by a case of using a scanning type exposure apparatus (a so-called scanning stepper) as the exposure apparatus EX that exposes the substrate P with the pattern formed on the mask M while synchronously moving the mask M and the substrate P in the scanning direction (prescribed direction) in mutually different directions (reverse directions). In the following explanation, the direction in which the mask M and the substrate P synchronously move (scanning direction) within the horizontal plane is the X axial direction, the direction orthogonal to the X axial direction within the horizontal plane is the Y axial direction (non-scanning direction), and the direction perpendicular to the X axis and the Y axial direction and that coincides with an optical axis AX of the projection optical system PL is the Z axial direction. In addition, the rotational (inclined) directions around the X, Y, and Z axes are the .theta.X, .theta.Y, and .theta.Z directions, respectively. Furthermore, “substrate” herein includes on in which a semiconductor wafer is coated with a photoresist, and “mask” includes a reticle wherein a device pattern, which is reduction projected onto the substrate, is formed.
• The illumination optical system IL illuminates with the exposure light EL the mask M supported by the mask stage MST, and includes: an exposure light source; an optical integrator that uniformizes the intensity of the luminous flux emitted from the exposure light source; a condenser lens that condenses the exposure light EL from the optical integrator; a relay lens system; and a variable field stop that sets an illumination region on the mask M illuminated by the exposure light EL to be slit shaped; and the like. The illumination optical system IL illuminates the prescribed illumination region on the mask M with the exposure light EL, which has a uniform illumination intensity distribution. Examples of light that can be used as the exposure light EL emitted from the illumination optical system IL include: deep ultraviolet light (DUV light), such as the bright lines (g, h, and i lines) in the ultraviolet region emitted from a mercury lamp for example, and KrF excimer laser light (248 mm wavelength); and vacuum ultraviolet light (VUV light), such as ArF excimer laser light (193 cm wavelength) and F.sub.2 laser light (157 nm wavelength). ArF excimer laser light is used in the present embodiment. As discussed above, theliquid1 in the present embodiment is pure water, and the exposure light EL can transmit therethrough even if it is light from an ArF excimer laser. In addition, the bright lines (g, h, and i lines) of the ultraviolet region, as well as deep ultraviolet light (DUV light), such as KrF excimer laser light (248 mm wavelength), can also transmit through pure water.
• The mask stage MST supports the mask M, and is two dimensionally movable in the plane perpendicular to the optical axis AX of the projection optical system PL, i.e., in the XY plane, and is finely rotatable in the .theta.Z direction. A mask stage drive apparatus MSTD, such as a linear motor, drives the mask stage MST. Amovable mirror50 is provided on the mask stage MST. In addition, alaser interferometer51 is provided at a position opening themovable mirror50. The control apparatus CONT controls the mask stage drive apparatus MSTD. Alaser interferometer51 measures in real time the position in the two dimensional direction and the rotational angle of the mask M on the mask stage MST, and outputs these measurement results to the control apparatus CONT. The control apparatus CONT drives the mask stage drive apparatus MSTD based on the measurement results of thelaser interferometer51, thereby positioning the mask M, which is supported by the mask stage MST.
• The projection optical system PL projects and exposes the pattern of the mask M onto the substrate P at a prescribed projection magnification .beta., and includes a projection optical system main body MPL, which includes a plurality of optical elements, and anoptical element2, which is provided at the front part on the substrate P side (on the image plane side of the projection optical system PL). The plurality of optical elements, which constitute the projection optical system main body MPL, are held by a lens barrel PK, and theoptical element2 at the front part of the projection optical system PL is held by a lens cell LS. Furthermore, the lens cell LS that holds theoptical element2 and the front part of the lens barrel PK are coupled by acoupling device150, which includes a plurality oflink parts151.
• In the present embodiment, the projection optical system PL is a reduction system that has a projection magnification .beta. of, for example, ¼ or ⅕. Furthermore, the projection optical system PL may be a unity magnification system or an enlargement system. The front partoptical element2 and the lens cell LS contact theliquid1 in the immersion area AR2.
• Theoptical element2 is made of fluorite. Because fluorite has a high affinity for pure water, theliquid1 can be adhered to substantially the entire surface of aliquid contact surface2aof theoptical element2. Namely, because the liquid (water)1 supplied in the present embodiment has a high affinity for theliquid contact surface2aof theoptical element2, theliquid contact surface2aof theoptical element2 and theliquid1 have strong adhesion characteristics, and theoptical element2 may therefore be made of quartz, which has a strong affinity for water. In addition, theliquid contact surface2aof theoptical element2 may be given hydrophilic (lyophilic) treatment in order to further raise its affinity for theliquid1.
• In addition, the exposure apparatus EX includes afocus detection system4. In thefocus detection system4, which includes alight emitting part4aand alight receiving part4b, detection light is projected from thelight emitting part4athrough the liquid1 from a diagonal direction onto the surface of the substrate P (the exposure surface), and the reflected light thereof is received by thelight receiving part4b. The control apparatus CONT controls the operation of thefocus detection system4 and, based on the light receiving result of thelight receiving part4b, detects the position (the focus position) of the surface of the substrate P with respect to a prescribed reference surface in the Z axial direction. In addition, by deriving a focus position at each of a plurality of points on the surface of the substrate P, thefocus detection system4 can derive the attitude of the substrate P in an inclination direction. Furthermore, it is possible to use as the constitution of thefocus detection system4 the one disclosed in, for example, Japanese Unexamined Patent Application, First Publication No. H08-37149 and the corresponding U.S. Pat. No. 6,327,025. In addition, the disclosures of the abovementioned Japanese publication and the corresponding U.S. patent are each hereby incorporated by reference in its entirety to the extent permitted by the national laws and regulations of the designated states (or elected states) designated by the present international patent application.
• The substrate stage PST supports the substrate P and includes aZ stage52, which holds the substrate P via a substrate holder, anXY stage53, which supports theZ stage52, and abase54, which supports theXY stage53. A substrate stage drive apparatus PSTD, such as a linear motor, drives the substrate stage PST. The control apparatus CONT controls the substrate stage drive apparatus PSTD. Furthermore, the Z stage and the XY stage may of course be provided integrally. The position of the substrate P in the XY direction (the position in the direction substantially parallel to the image plane of the projection optical system PL) is controlled by driving theXY stage53 of the substrate stage PST.
• Movable mirrors (reflecting mirrors)55 are provided to the side portions of the substrate stage PST (Z stage52). In addition, alaser interferometer56 is provided at a position opposing each of the movable mirrors55. Eachlaser interferometer56 measures in real time the position in the two dimensional directions and the rotational angle of the substrate P on the substrate stage PST, and these measurement results are output to the control apparatus CONT. Based on the measurement results of eachlaser interferometer56, the control apparatus CONT drives theXY stage53 via the substrate stage drive apparatus PSTD, which positions the substrate P, which is supported by the substrate stage PST, in the X axial direction and the Y axial direction.
• In addition, by driving theZ stage52 of the substrate stage PST via the substrate stage drive apparatus PSTD, the control apparatus CONT controls the position of the substrate P, which is supported by theZ stage52, in the Z axial direction (focus position) and in the .theta.X, .theta.Y directions. Namely, theZ stage52 operates based on a command, which is based on the detection results of thefocus detection system4, from the control apparatus CONT, controls the focus position (Z position) and the inclination angle of the substrate P, and aligns the surface thereof (exposure surface) with the image plane formed through the projection optical system PL and theliquid1.
• Anauxiliary plate57 is provided on the substrate stage PST (Z stage52) so that it surrounds the substrate P. Theauxiliary plate57 includes a flat surface at a height substantially the same as that of the surface of the substrate P held by the substrate holder. Here, there is a gap of approximately 0.1-1 mm between the edge of the substrate P and theauxiliary plate57, but due to the surface tension of the liquid1 there is virtually no flow of the liquid1 into that gap, and theliquid1 can therefore be held below the projection optical system PL by theauxiliary plate57, even when exposing the vicinity of the circumferential edge of the substrate P.
• In addition, areference member7, which has fiducial marks MFM, PFM used in the process of aligning the mask M and the substrate P, is provided on the substrate stage PST (Z stage52). Furthermore, asubstrate alignment system5, which detects the alignment mark on the substrate P or the fiducial mark PFM provided to thereference member7, is provided in the vicinity of the front of the projection optical system PL. In addition, a mask alignment system6 is provided in the vicinity of the mask stage MST and detects, through the mask M and the projection optical system PL, the fiducial mark MFM provided to thereference member7. Furthermore, the system disclosed in, for example, Japanese Unexamined Patent Application, First Publication No. H04-65603 and the corresponding U.S. Pat. No. 5,493,403 can be used to constitute thesubstrate alignment system5, and the system disclosed in Japanese Unexamined Patent Application, First Publication No. H07-176468 and the corresponding U.S. Pat. No. 5,646,413 can be used to constitute the mask alignment system6.
• Furthermore, the disclosures of the abovementioned Japanese publications and corresponding U.S. patents are each hereby incorporated by reference in its entirety to the extent permitted by the national laws and regulations of the designated states (or elected states) designated by the present international patent application.
• Furthermore, alight receiving device8, which receives the light irradiated through the projection optical system PL and onto the image plane side thereof (the substrate P side), is provided on the substrate stage PST (Z stage52). Thelight receiving device8 includes alight transmitting member8A, which consists of a glass plate provided on theZ stage52, and alight receiving element8B, which is embedded in theZ stage52, that receives light through thelight transmitting member8A.
• A firstliquid removing apparatus40, which removes theliquid1 remaining on and adhered to thereference member7 provided to theZ stage52, is provided in the vicinity of thesubstrate alignment system5. In addition, aliquid recovery apparatus30, which recovers theliquid1, is provided to the substrate stage PST.
• Theliquid supply mechanism10 supplies the prescribed liquid1 onto the substrate P from above in order to form the immersion area AR2, and includes: aliquid supply apparatus11, which is capable of feeding theliquid1; andsupply nozzles13, which are connected to theliquid supply apparatus11 through asupply pipe12, which has a passageway, that each have a supply port through which theliquid1, which is fed from thisliquid supply apparatus11, is supplied to the substrate P. Theliquid supply apparatus11 includes a tank that stores theliquid1, a pressurizing pump, and the like, and supplies theliquid1 to the substrate P through thesupply pipe12 and thesupply nozzles13. The control apparatus CONT controls the operation wherein the liquid is supplied by theliquid supply apparatus11, and can independently control the amount of liquid supplied per unit of time to the substrate P by theliquid supply apparatus11. In addition, theliquid supply apparatus11 includes a mechanism for adjusting the temperature of theliquid1, and supplies the substrate P with theliquid1, which has a temperature (for example, 23.degree. C.) substantially the same as that inside the chamber apparatus CH that houses the apparatus. Thesupply nozzles13 are disposed proximate to the substrate P, and supply theliquid1 to the substrate P from above it. In addition, thesupply nozzles13 contact theliquid1 in the immersion area AR2 during immersion exposure.
• Theliquid recovery mechanism20 recovers theliquid1 on the substrate P from above it, and includesrecovery nozzles23, which each have a recovery port disposed proximate to the surface of the substrate P, and aliquid recovery apparatus21, which is connected to therecovery nozzles23 through arecovery pipe22 that has a passageway. Theliquid recovery apparatus21 includes a vacuum system (suction apparatus), e.g., a vacuum pump, a tank that stores the recoveredliquid1, and the like, and recovers theliquid1 on the substrate P through therecovery nozzles23 and therecovery pipe22. The control apparatus CONT controls the operation of recovering the liquid by theliquid recovery apparatus21, and can control the amount of liquid recovered per unit of time thereby. The recovery nozzles23 contact theliquid1 in the immersion area AR2 during immersion exposure, and theliquid recovery mechanism20 sucks and recovers theliquid1 on the substrate P from above it through therecovery nozzles23.
• FIG. 2 depicts the positional relationships between the projection area AR1 of the projection optical system PL, the supply nozzles13 (13A-13C) that supply theliquid1 in the X axial direction, and the recovery nozzle23 (23A-23B) that recover theliquid1. InFIG. 2, the shape of the projection area AR1 of the projection optical system PL is a rectangle that is long and thin in the Y axial direction, and part of the pattern image of the mask M is projected to that projection areas AR1. Threesupply nozzles13A-13C are disposed on the +X direction side, and tworecovery nozzles23A,23B are disposed on the −X direction side so that the projection area AR1 is interposed therebetween in the X axial direction. Furthermore, thesupply nozzles13A-13C are connected to theliquid supply apparatus11 via thesupply pipe12, and therecovery nozzles23A,23B are connected to theliquid recovery apparatus21 via therecovery pipe22. In addition,supply nozzles15A-15C andrecovery nozzles25A,25B are disposed at positions obtained by rotating, by substantially 180.degree., the positions of thesupply nozzles13A-13C and therecovery nozzles23A,23B. Thesupply nozzles13A-13C and therecovery nozzles25A,25B are arrayed alternately in the Y axial direction, thesupply nozzles15A-15C and therecovery nozzles23A,23B are arrayed alternately in the Y axial direction, thesupply nozzles15A-15C are connected to theliquid supply apparatus11 via asupply pipe14, and therecovery nozzles25A,25B are connected to theliquid recovery apparatus21 via arecovery pipe24.
• Further, the substrate P moves in the +X direction (or −X direction) at a speed .beta.V (where .beta. is the projection magnification) via theXY stage53, which is synchronized to the movement of the mask M at the speed V in the −X direction (or +X direction) with respect to the projection optical system PL. After the exposure of one shot region is completed, the next shot region moves to the scanning start position by the stepping of the substrate P, and the exposure process is then successively performed for each shot region by the step-and-scan system.
• In the present embodiment, the control apparatus CONT flows theliquid1 along the movement direction of the substrate P. For example, if scanning exposure is being performed by moving the substrate P in the scanning direction (−X direction) depicted by, for example, the arrow Xa, then theliquid1 is supplied and recovered by theliquid supply apparatus11 and theliquid recovery apparatus21 using thesupply pipe12, thesupply nozzles13A-13C, therecovery pipe22, and therecovery nozzles23A,23B. Namely, when the substrate P moves in the −X direction, theliquid1 is supplied from theliquid supply apparatus11, through thesupply pipe12 and the supply nozzles13 (13A-13C), between the projection optical system PL and the substrate P, is recovered by theliquid recovery apparatus21 through the recovery nozzles23 (23A,23B) and therecovery pipe22, and thereby flows in the −X direction so that it fills the space between theoptical element2 and the substrate P. Meanwhile, if scanning exposure is performed by moving the substrate P in the scanning direction (+X direction) depicted by the arrow Xb, then theliquid1 is supplied and recovered by theliquid supply apparatus11 and theliquid recovery apparatus21 using thesupply pipe14, thesupply nozzles15A-15C, therecovery pipe24, and therecovery nozzles25A,25B. Namely, when the substrate P moves in the +X direction, theliquid1 is supplied from theliquid supply apparatus11, through thesupply pipe14 and the supply nozzles15 (15A-15C), between the projection optical system PL and the substrate P, is recovered by theliquid recovery apparatus21 through the recovery nozzles25 (25A,25B) and therecovery pipe24, and thereby flows in the +X direction so that it fills the space between theoptical element2 and the substrate P. Thus, the control apparatus CONT uses theliquid supply apparatus11 and theliquid recovery apparatus21 to flow theliquid1 along the movement direction of the substrate P in a direction identical thereto. In this case, theliquid1, which is supplied, for example, from theliquid supply apparatus11 through thesupply nozzles13, flows with the movement of the substrate P in the −X direction so that it is drawn into the space between the projection optical system PL and the substrate P, and it is therefore possible to easily supply theliquid1 thereto even if the supplied energy of theliquid supply apparatus11 is small. Furthermore, by switching the direction of flow of the liquid1 in accordance with the scanning direction, it is possible to fill theliquid1 between theoptical element2 at the front part of the projection optical system PL and the substrate P, and to obtain a high resolution and great depth of focus regardless of whether the substrate P is scanned in the +X direction or the −X direction.
• Furthermore, the present invention is not particularly limited to the configuration of the nozzles discussed above, and theliquid1 may be supplied and recovered by, for example, two pairs of nozzles disposed along the long sides of the projection area AR1. Furthermore, in this case, theliquid1 can also be supplied and recovered from either the +X direction or the −X direction, and the supply nozzles and the recovery nozzles may consequently be arrayed vertically. In addition, the nozzles that supply and recover theliquid1 are provided at prescribed intervals around theoptical element2 of the projection optical system PL, and it is therefore possible to flow theliquid1 in a direction parallel to and the same as the movement direction of the substrate P, even if the substrate P moves in a direction other than the scanning direction (the +X direction and the −X direction).
• FIG. 3 is a schematic plan view of theZ stage52 of the substrate stage PST, viewed from above. The movable mirrors55 (55X,55Y) are disposed on two mutually perpendicular side surfaces of therectangular Z stage52. Specifically, themovable mirror55X is provided to the end part of theZ stage52 on the +X side so that it extends in the Y axial direction, and themovable mirror55Y is provided to the end part of theZ stage52 on the +Y side so that it extends in the X axial direction. Furthermore, the substrate P is held via a holder (not shown) at substantially the center of theZ stage52.
• The laser interferometers56 (56X,56Y), which irradiate themovable mirrors55 with the laser light (measurement beam), are disposed at a position opposing the movable mirrors55 (55X,55Y), respectively. Furthermore, blow outnozzles91 are provided in the vicinity of each of thelaser interferometers56, which are on the outer side of the substrate stage PST, and each blow outnozzle91 includes a gas blow outport91A and constitutes part of a secondliquid removing apparatus90, which removes the liquid1 adhering to the correspondingmovable mirror55 by blowing the gas thereagainst. In the present embodiment, the blow outnozzles91 are provided on both sides of, and sandwiches, eachlaser interferometer56.
• A groove part (upper groove part)58 is formed at the upper part of eachmovable mirror55 along the longitudinal direction thereof. Vibratingapparatuses92 are provided at a plurality of prescribed positions on the inner side of thegroove part58 of eachmovable mirror55 and vibrates such. In the present embodiment, each vibratingapparatus92 is made of a piezoelectric film, which is a piezoelectric device, and is affixed at each of three locations along the longitudinal direction at the center portion and at both end portions of thegroove part58 of eachmovable mirror55. Furthermore, the installation position and the number ofpiezoelectric films92 can be arbitrarily set.
• Theauxiliary plate57, which has a flat surface at a height substantially the same as that of the surface of the substrate P as discussed above, is provided around the substrate P. Furthermore, aliquid absorbing member31, which constitutes part of the stageliquid recovery apparatus30 that recovers theliquid1, is provided around theauxiliary plate57. Theliquid absorbing member31 is an annular member that has a prescribed width, and is disposed in a groove part (recovery port)33 annularly formed in theZ stage52. Theliquid absorbing member31 is made of a porous material, e.g., porous ceramics or the like. Alternatively, sponge, which is a porous material, may be used as the material for forming theliquid absorbing member31. Theliquid absorbing member31 that is made of a porous material can hold a prescribed amount of theliquid1.
• Thereference member7 is provided at one corner of theZ stage52. The fiducial mark PFM, which is detected by thesubstrate alignment system5, and the fiducial mark MFM, which is detected by the mask alignment system6, are provided to thereference member7 with a prescribed positional relationship. In addition, the surface of thereference member7 is substantially flat and serves the role of a reference surface of thefocus detection system4.
• Furthermore, the reference surface of thefocus detection system4 may be provided on theZ stage52 separately from thereference member7. In addition thereference member7 and theauxiliary plate57 may be integrally provided.
• Furthermore, aliquid absorbing member42, which recovers the liquid1 removed from thereference member7 by the firstliquid removing apparatus40, is provided on theZ stage52 in the vicinity of thereference member7. Theliquid absorbing member42 is disposed in agroove part44, which is formed in theZ stage52. Furthermore, a gas blow outport64A of anozzle part64 that constitutes part of a thirdliquid removing apparatus60, which removes the liquid1 that remains on and adheres to theoptical element2 at the front part of the projection optical system PL and the lens cell LS that holds thisoptical element2, is disposed at a separate corner of theZ stage52, and aliquid absorbing material65, which recovers the liquid1 removed from theoptical element2, is provided in the vicinity of that gas blow outport64A. Theliquid absorbing material65 is disposed in agroove part66 formed in theZ stage52.
• Furthermore, thelight transmitting member8A is provided at a separate corner of theZ stage52, and constitutes part of thelight receiving device8 that receives the light irradiated through the projection optical system PL to the image plane side (the substrate P side) thereof. Thelight transmitting member8A is patterned with a film that includes a light shielding material, such as chromium, on the surface of a glass plate, and at the center part thereof is provided a slit part88, which is a light transmitting part with its longitudinal direction in the Y axial direction. The light irradiated through the projection optical system PL to the image plane side thereof passes through theslit8S and is received by thelight receiving element8B, which is embedded in theZ stage52. Furthermore, aliquid absorbing member142, which recovers the liquid1 removed from thelight transmitting member8A, is provided on theZ stage52 in the vicinity of thelight transmitting member8A. Theliquid absorbing member142 is disposed in agroove part144, which is formed in theZ stage52.
• FIG. 4 is a cross sectional view that depicts the stageliquid recovery apparatus30. The stageliquid recovery apparatus30 includes: the above discussedliquid absorbing member31, which is disposed in the groove part (recovery part)33 formed annularly in theZ stage52; apassageway32 formed inside theZ stage52 and continuous with thegroove part33; aconduit36 provided external to theZ stage52 and wherein one end is connected to thepassageway32; atank37 connected to the other end of theconduit36 and provided external to theZ stage52; and apump39, which is a vacuum system (suction apparatus), connected to thistank37 through aconduit38 that has avalve38A. Thetank37 is provided with adischarge passageway37A, and is constituted so that theliquid1 is discharged from thedischarge passageway37A when a prescribed amount has accumulated. Furthermore, in the stageliquid recovery apparatus30, thepump39 is driven, which collects the liquid1 recovered by theliquid absorbing member31 so that it is sucked into thetank37.
• The following explains the procedure for using the exposure apparatus EK, which is discussed above, to expose the substrate P with the pattern of the mask M.
• Before supplying the liquid1 from theliquid supply mechanism10, the measurement process is first performed in a state wherein there is no liquid1 on the substrate P. The control apparatus CONT moves theXY stage53 while monitoring the outputs of thelaser interferometers56 so that the optical axis AX of the projection optical system PL proceeds along abroken line arrow18 inFIG. 3. During that movement, thesubstrate alignment system5 detects, although not through theliquid1, a plurality of alignment marks (not shown) formed on the substrate P corresponding to shot regions S1-S11. Furthermore, theXY stage53 stops when thesubstrate alignment system5 detects an alignment mark. As a result, the position information of each alignment mark is measured within a coordinate system defined by thelaser interferometers56. Furthermore, thesubstrate alignment system5 may detect all, or a portion of, the alignment marks on the substrate P.
• In addition, during the movement of theXY stage53, thefocus detection system4 detects, although not through theliquid1, the surface information of the substrate P. Thefocus detection system4 detects the surface information for all shot regions S1-S11 on the substrate P, and stores the detection results in the control apparatus CONT associated with the position on the substrate P in the scanning direction (X axial direction). Furthermore, thefocus detection system4 may detect the surface information of just a portion of the shot regions.
• When the detection of the alignment marks on the substrate P and of the surface information of the substrate P are complete, the control apparatus CONT moves theXY stage53 so that the detection area of thesubstrate alignment system5 is positioned on thereference member7. Thesubstrate alignment system5 detects the fiducial mark PFM on thereference member7, and measures the position information of the fiducial mark PFM within the coordinate system defined by thelaser interferometers56.
• The positional relationships between the fiducial mark PFM and the plurality of alignment marks on the substrate P, i.e., the positional relationships between the fiducial mark PFM and the plurality of shot regions S1-S11 on the substrate P, are each derived by the completion of the process of detecting the fiducial mark PFM. In addition, because the fiducial mark PFM and the fiducial mark MFM are in a prescribed positional relationship, the positional relationships between the fiducial mark MFM and the plurality of shot regions S1-S11 on the substrate P are each determined within the XY plane.
• In addition, before and after the detection of the fiducial mark PFM by thesubstrate alignment system5, the control apparatus CONT detects the surface information of the reference member7 (the reference surface) by thefocus detection system4. The relationship between the surface of thereference member7 and the surface of the substrate P is derived by completing the process of detecting the surface of thisreference member7.
• Next, the control apparatus CONT moves theXY stage53 so that the fiducial mark MFM on thereference member7 can be detected by the mask alignment system6. As might be expected, the front part of the projection optical system PL opposes thereference member7 in this state. At this point, the control apparatus CONT starts the supply and recovery of theliquid1 by theliquid supply mechanism10 and theliquid recovery mechanism20, and forms the immersion area by filling theliquid1 between the projection optical system PL and thereference member7.
• Next, the control apparatus CONT detects the fiducial mark MFM by the mask alignment system6 through the mask M, the projection optical system PL, and theliquid1. Thereby, the fiducial mark MFM is used to detect, through the projection optical system PL and theliquid1, the position of the mask M within the XY plane, i.e., the projection position information of the pattern image of the mask M.
• When the above measurement process is complete, the control apparatus CONT stops the operation of supplying theliquid1 to thereference member7 by theliquid supply mechanism10. However, the control apparatus CONT continues the operation of recovering theliquid1 on thereference member7 by theliquid recovery mechanism20 for a prescribed time period. Then, the control apparatus CONT stops the recovery operation by theliquid recovery mechanism20 after the above prescribed time period has elapsed, and moves the substrate stage PST in order to remove theliquid1 that was not completely recovered by theliquid recovery mechanism20 and therefore remains on thereference member7.
• FIGS. 5A and 5B depict an aspect wherein the firstliquid removing apparatus40 removes theliquid1 remaining on thereference member7, which is provided on the substrate stage PST (Z stage52);FIG. 5A is a schematic oblique view, andFIG. 5B is a cross sectional view. InFIG. 5A andFIG. 5B, the firstliquid removing apparatus40 includes a blowingapparatus41 that blows the gas against thereference member7, and a vibratingapparatus43B that vibrates thereference member7. As depicted inFIG. 5B, thereference member7 is supported by asupport part7A, which is installed in a recessedpart52A formed in theZ stage52, and aspace7S is formed between thereference member7 and the recessedpart52A. Thereference member7 is a plate shaped member, and thesupport part7A supports the edge parts of thelower surface7K of thereference member7. Furthermore, the vibratingapparatus43B is provided at the center part of thelower surface7K of thereference member7. The vibratingapparatus43B includes a piezoelectric device, and the control apparatus CONT uses thispiezoelectric device43B to vibrate thereference member7 by applying a prescribed voltage to the piezoelectric device (vibrating apparatus)43B.
• The blowingapparatus41 includes agas supply part41A, which is capable of feeding the gas, and anozzle part43, which is connected to thegas supply part41A. A gas blow outport43A of thenozzle part43 is formed in a slit shape, and is disposed proximate to thereference member7. Thegas supply part41A and thenozzle part43 are supported by a support part (not shown), which is independent of the projection optical system PL.
• Theliquid absorbing member42, which recovers (holds) the liquid removed from thereference member7 by the firstliquid removing apparatus40, is provided on theZ stage52 at a position proximate to thereference member7. Theliquid absorbing member42 is provided at a position opposing the gas blow outport43A of thenozzle part43 so that thereference member7 is interposed therebetween. Theliquid absorbing member42 is disposed in thegroove part44, which is a recovery port provided in theZ stage52. Like theliquid absorbing member31 of the stageliquid recovery apparatus30, theliquid absorbing member42 is made of a porous material, e.g., porous ceramics, sponge, or the like, and is capable of holding a prescribed amount of theliquid1.
• Thegas supply part41A feeds the gas, and high speed gas is thereby blown, from a diagonal direction, through the slit shaped gas blow outport43A of thenozzle part43 against thereference member7. The control apparatus CONT blows off and removes theliquid1 remaining on and adhered to thereference member7 by blowing the gas from thenozzle part43 of the firstliquid removing apparatus40 against thereference member7. At this time, the control apparatus CONT blows the gas from thenozzle part43 against thereference member7 while moving the substrate stage PST (i.e., the reference member7) with respect to the nozzle part43 (gas blow outport43A) of the firstliquid removing apparatus40, and the gas can thereby be blown against the entire surface of thereference member7 without missing any part. The liquid1 that was blown off is held (recovered) by theliquid absorbing member42, which is disposed at a position opposing the gas blow outport43A of thenozzle part43.
• In the present embodiment, the gas from the gas blow outport43A of thenozzle part43 is blown against thereference member7, while using thepiezoelectric device43B to vibrate thereference member7. Vibrating thereference member7 promotes the removal (shaking off) of theliquid1 and such can be satisfactorily removed from thereference member7 by blowing the gas thereagainst.
• Apassageway45, which is continuous with thegroove part44, is formed inside theZ stage52, and the bottom part of theliquid absorbing member42, which is disposed in thegroove part44, is connected to thepassageway45. Thepassageway45, which is connected to thegroove part44 wherein theliquid absorbing member42 is disposed, is connected to one end of aconduit46 that is provided external to theZ stage52. Meanwhile, the other end of theconduit46 is connected to apump49, which is a suction apparatus, through atank47 provided external to theZ stage52 and aconduit48 that has avalve48A. Adischarge passageway47A is provided to thetank47 and is constituted so that the liquid1 discharges from thedischarge passageway47A when a prescribed amount accumulates. Then, the control apparatus CONT drives thegas supply part41A of the firstliquid removing apparatus40 and drives thepump49, and the liquid1 recovered by theliquid absorbing member42 is thereby collected so that it is sucked into thetank47. Namely, theliquid absorbing member42, thetank47, thepump49; and the like constitute a liquid recovery mechanism that recovers the liquid1 removed from thereference member7.
• Subsequently, in order to expose each of the shot regions S1-S11 on the substrate P, the control apparatus CONT moves theXY stage53 so as to mutually oppose the projection optical system PL and the substrate P. After mutually opposing the projection optical system PL and the substrate P, the control apparatus CONT drives theliquid supply mechanism10 to start the operation of supplying the liquid onto the substrate P. The liquid, which is fed from theliquid supply apparatus11 of theliquid supply mechanism10 in order to form the immersion area AR2 on the substrate P, is distributed through thesupply pipe12, and then supplied onto the substrate P through thesupply nozzles13, thereby forming the immersion area AR2 between the projection optical system PL and the substrate P. The liquid1 supplied onto the substrate P forms the immersion area AR2, which has an area that is at least as large as the projection area AR1, on the substrate P. In addition, the control apparatus CONT controls theliquid recovery apparatus21 of theliquid recovery mechanism20, and theliquid supply mechanism10 performs the operation of recovering the liquid on the substrate P in parallel with the operation of supplying theliquid1. In other words, in order to form the immersion area AR2 during the exposure of the substrate P, the control apparatus CONT simultaneously performs the operations of supplying the liquid by theliquid supply mechanism10 and recovering the liquid by theliquid recovery mechanism20. Theliquid1 on the substrate P is recovered from the recovery port of therecovery nozzles23.
• Then, each of the shot regions S1-S11 on the substrate P is scanning exposed using the various information derived during the previously discussed measurement process. Namely, during the scanning exposure of each of the shot regions S1-S11, each shot region on the substrate P is aligned with the mask M based on: the information of the positional relationship between the fiducial mark PFM and each of the shot regions S1-S11 derived before supplying theliquid1; and the projection position information of the pattern image of the mask M derived using the fiducial mark MFM after supplying theliquid1.
• In addition, during the scanning exposure of each of the shot regions S1-S11, the positional relationship between the surface of the substrate P and the image plane formed through theliquid1 is adjusted, without using thefocus detection system4, based on the surface information of the substrate P, which was derived before supplying theliquid1.
• During the scanning exposure of each of the shot regions S1-S11, the liquid from the immersion area AR2 formed on the substrate P may scatter to the outer side of the substrate P. For example, if the liquid1 that scatters from the substrate P during the exposure thereof adheres to the reflecting surfaces of themovable mirrors55, then the measurement beam irradiated thereupon thelaser interferometers56 will scatter or the like due to theliquid1 adhering to themovable mirrors55, and there is a possibility that it will no longer be possible to accurately measure the position of the substrate stage PST by thelaser interferometers56. Accordingly, when the control apparatus CONT has determined that theliquid1, which scattered from the substrate P, has adhered to themovable mirrors55, it starts the process of removing the liquid from themovable mirrors55 by the secondliquid removing apparatuses90.
• At this point, when thelaser interferometers56 irradiates themovable mirror55 with the measurement beam, the amount of reflected light from thatmovable mirror55 received by thelaser interferometer56 is reduced if theliquid1 has adhered to themovable mirror55. The control apparatus CONT can determine whether theliquid1 has adhered to themovable mirror55 based on the measurement result (light receiving result) of thelaser interferometer56, i.e., based on the amount of reflected light received from thatmovable mirror55.
• For example, if it is determined that theliquid1 has adhered to themovable mirrors55 during the exposure of the sixth shot region S6, then, after the scanning exposure of the sixth shot region S6 is complete, the control apparatus CONT performs the process of removing the liquid by the secondliquid removing apparatus90 during the time period before the start of the scanning exposure of the following seventh shot region S7.
• FIG. 6 is a cross sectional view that depicts the operation of using the secondliquid removing apparatuses90 to remove theliquid1 that has adhered to the movable mirror55 (55X). Furthermore, the following explains the case of removing theliquid1 adhering to themovable mirror55X that is provided to the end part of theZ stage52 on the +X side, but a similar operation is executed also for the case of removing theliquid1 adhering to themovable mirror55Y that is provided to the end part of theZ stage52 on the +Y side.
• InFIG. 6, the movable mirror55 (55X) includes anupper groove part58 that is formed in the upper part of the movable mirror55 (55X) in a notch shape along the longitudinal direction (Y axial direction) thereof, and alower groove part59 that is formed in the lower part of the movable mirror55 (55X) in a notch shape along the longitudinal direction thereof, and substantially forms an H shape in a cross sectional view. Within themovable mirror55 formed in an H shape in a cross sectional view, an innerside flange part55A, which is formed on one side of aweb part55C, is connected to theZ stage52, and anouter side surface55S of an outerside flange part55B, which is formed on the other side of theweb part55C, includes a reflecting surface for the measurement beam irradiated by thelaser interferometer56. Furthermore, the outerside flange part55B of themovable mirror55 is supported at the center part in the height direction (Z axial direction) thereof by theweb part55C, and anupper end part55J constitutes a free end. The measurement beam from thelaser interferometer56 is irradiated upon the vicinity of theupper end part55J (namely, in the vicinity of the free end) of the reflecting surface (outer side surface)55S of the outerside flange part55B. Furthermore, the entirety of themovable mirror55 is made of ceramics, optical glass, or the like, and a reflecting surface is formed on theouter side surface55S by vacuum depositing thereupon a material that has light reflecting properties, such as a metal.
• The secondliquid removing apparatus90 includes the blow outnozzle91, which is provided in the vicinity of thelaser interferometer56 and has the gas blow outport91A, and the piezoelectric film (vibrating apparatus)92, which is provided on the inner side of thegroove part58 of themovable mirror55 and that vibrates such. Thepiezoelectric film92 is affixed to aninner side surface55D, which faces thegroove part58, of the outerside flange part55B that has the reflectingsurface55S of themovable mirror55. More specifically, thepiezeoelectric film92 is affixed at the vicinity of theupper end part55J, which is the free end of the vibrations, of theinner side surface55D of the outershape flange part55B. Thepiezoelectric film92 is constituted so that it expands and contracts in the vertical direction (Z axial direction), as depicted by the arrow z1 inFIG. 6, in a state affixed to theinner side surface55D, and the expanding and contracting operation of thispiezoelectric film92 vibrates the vicinity of theupper end part55J of the outerside flange part55B, with the web part (support part)55C as the base end, in the .theta.Y direction as depicted by the arrow b1. Vibrating the outerside flange part55B by thepiezoelectric film92 promotes the removal of the liquid1 adhering to the outerside flange part55B (reflectingsurface55S). In particular, by vibrating the vicinity of theupper end part55J, which is the free end of the outerside flange part55B, the position at which the measurement beam from thelaser interferometer56 irradiates the reflectingsurface55S is particularly vibrated, and theliquid1 adhering at the position where the measurement beam irradiates the reflectingsurface55S (i.e., the vicinity of theupper end part55J) can be satisfactorily removed.
• Blow outnozzles91 are provided respectively on both sides of each laser interferometer56 (refer toFIG. 3), and the gas blow outparts91A blow the gas against themovable mirror55 from the diagonally upward direction. Each blow outnozzle91 is provided movable in the vertical direction (Z axial direction) by a drive mechanism (not shown), and the gas can therefore be blown against themovable mirror55 without missing any part.
• A secondliquid recovery mechanism100, which recovers the liquid1 removed from themovable mirror55, is provided on the outer side of the substrate stage PST. The secondliquid recovery mechanism100 includes aprocessing mechanism101, which is provided on the outer side of the substrate stage PST, that processes theliquid1 removed and dropped from themovable mirror55. Theprocessing mechanism101 is provided on the outer side of the substrate stage PST below the blow outnozzle91, and includes adrain member102 that recovers theliquid1, and adischarge mechanism103 that discharges theliquid1 recovered by thedrain member102. Thedischarge mechanism103 includes atank105, which is connected to thedrain member102 through aconduit104, and apump107, which is a vacuum system (suction apparatus), that is connected to thetank105 through aconduit106. Avalve106A, which opens and closes the passageway of theconduit106, is provided midway therein. Thedrain member102 is disposed inside the chamber apparatus CH, and thedischarge mechanism103 is disposed outside of the chamber apparatus CH. Adischarge passageway105A is provided to thetank105, and is constituted so that the liquid1 from thedrain member102 is discharged from thedischarge passageway105A when a prescribed amount has accumulated. Furthermore, in thedischarge mechanism103, thepump107 is driven, and the liquid1 recovered by thedrain member102 is collected so that it is sucked into thetank105.
• For example, if it is determined that theliquid1 has adhered to themovable mirror55 during the exposure of the sixth shot region S6, then the control apparatus CONT stores that information related to the sixth shot region S6 after the scanning exposure thereof is complete. The information related to the sixth shot region S6 includes the position information of the substrate stage PST when that sixth shot region S6 was exposed (i.e., the position information of the sixth shot region S6). The position information of the substrate stage PST at that time can be derived based on the measurement result of thelaser interferometer56. Furthermore, after storing the information related to the sixth shot region S6, the control apparatus CONT moves the substrate stage PST so that themovable mirror55 approaches the vicinity of the blow outnozzles91, which is the liquid removing process position.
• The control apparatus CONT moves the substrate stage PST so that themovable mirror55 moves between the secondliquid recovery mechanism100 and the blow outnozzles91, which is the liquid removing process position, and then drives a compressed air supply apparatus (not shown) and blows the gas, from the diagonally upward direction, against the reflectingsurface55S of themovable mirror55 from the gas blow outports91A of the blow outnozzles91. Furthermore, the control apparatus CONT drives thepiezoelectric film92 to vibrate themovable mirror55 in parallel with the operation of blowing the gas from the blow outnozzles91. The vibration of themovable mirror55 promotes the removal (shaking off) of theliquid1, and theliquid1 adhering to the reflectingsurface55S, which the gas was blown against from the gas blow outports91A of the blow outnozzles91, is removed and dropped from the reflectingsurface55S. At this time, the gas can be blown against themovable mirror55, without missing any part, by blowing gas against themovable mirror55 from the blow outnozzle91 while moving them in the vertical direction and moving the substrate stage PST in the horizontal direction (the Y axial direction). Furthermore, because the blow outnozzles91 are respectively provided on both sides of thelaser interferometer56, the gas can be blown against themovable mirror55 without missing any part in a state wherein the range of movement of the substrate stage PST is suppressed.
• Furthermore, when blowing the gas against themovable mirror55 from the blow outnozzles91, the blow outnozzles91 may be provided so that they are also movable in the horizontal direction (Y axial direction), and the blow outnozzles91 may be moved in the horizontal direction (Y axial direction) without moving the substrate stage PST in the horizontal direction (Y axial direction), and both the substrate stage PST and the blow outnozzles91 may be moved in the horizontal direction (Y axial direction). Likewise, instead of moving the blow outnozzles91 in the vertical direction (Z axial direction), the substrate stage PST may be moved in the vertical direction, and both the substrate state PST and the blow outnozzles91 may be moved in the vertical direction.
• Theliquid1, which is removed and dropped from themovable mirror55, is recovered in thedrain member102 of the secondliquid recovery mechanism100 and discharged outside of the chamber apparatus CH by thedischarge mechanism103 In so doing, theliquid1 does not accumulate in thedrain member102, and environmental fluctuations (humidity fluctuations) inside the chamber apparatus CH can thereby be prevented.
• In the present embodiment, the blow outnozzles91 can remove theliquid1 adhering to themovable mirror55 by blowing the gas continuously thereagainst from the diagonally upward direction, thereby ensuring that theliquid1 does not adhere to themovable mirror55. In addition, the gas may be blown intermittently against themovable mirror55, as previously discussed, without blowing the gas continuously. In so doing, theliquid1 adhering to themovable mirror55 can be more satisfactorily removed. In other words, if the gas is blown against themovable mirror55 continuously from the blow outnozzles91, as in the schematic drawing depicted inFIG. 7A, then a laminar flow area of the gas tends to form on the surface of the movable mirror55 (the reflecting surface), and there are cases wherein it is difficult to remove thisliquid1, e.g., if the droplets (water droplets) of the adheringliquid1 are small. However, by blowing the gas against themovable mirror55 intermittently, as in the schematic drawing depicted inFIG. 7B, a turbulent flow is formed on the surface of themovable mirror55, and that turbulent flow area can smoothly remove theliquid1 adhering to themovable mirror55.
• Furthermore, instead of blowing the gas against themovable mirror55 intermittently, a turbulent flow can also be formed on the surface of themovable mirror55 by varying the flow speed of that blown gas at a high frequency, thereby enabling theliquid1 that adhered to themovable mirror55 to be smoothly removed.
• Furthermore, even if the gas is blown against thereference member7 from thenozzle part43, as explained referencingFIG. 5A andFIG. 5B, that gas can be blown intermittently or blown while varying its flow speed.
• After the process of removing the liquid on themovable mirror55 by the secondliquid removing apparatuses90 is complete, the control apparatus CONT moves the substrate stage PST, based on the information related to the sixth shot region S6 (the position information of the sixth shot region S6) that was stored earlier, in order to disposed the seventh shot region S7 at the exposure start position for performing the next scanning exposure thereof. Furthermore, after the seventh shot region S7 is disposed at the exposure start position, the control apparatus CONT starts the scanning exposure of the seventh shot region S7, and subsequently exposes each of the eighth through eleventh shot regions successively.
• When the scanning exposure of each of the shot regions S1-S11 on the substrate P is complete, the control apparatus CONT stops the supply of the liquid by theliquid supply mechanism10, and moves the subsequent stage PST so that therecovery port33 of the stageliquid recovery apparatus30, which is provided to the substrate stage PST, opposes the projection optical system PL. Furthermore, the control apparatus CONT recovers theliquid1 below the projection optical system PL using theliquid recovery mechanism20 and the stageliquid recovery apparatus30 in combination. Thus, because theliquid1 in the immersion area AR2 is recovered simultaneously by theliquid recovery mechanism20, wherein the recovery port is disposed above the substrate stage PST (substrate P), and the stageliquid recovery apparatus30, wherein the recovery port is disposed in the substrate stage PST, it is possible to reduce theliquid1 remaining on the front of the projection optical system PL and on the substrate P.
• In addition, after the exposure of the substrate P is complete, the stageliquid recovery apparatus30 can recover theliquid1 in the immersion area AR2, as well as theliquid1 that flowed to the outer side of the substrate P (the auxiliary plate57) during the immersion exposure. In addition, although therecovery port33 of the stageliquid recovery apparatus30 is provided in an annular (tonic) shape around the substrate P, it may also be provided partially at a prescribed position in the vicinity of the substrate P (the auxiliary plate57), taking into consideration the movement direction of the substrate stage PST after the exposure of the substrate P is complete. In addition, before and after the immersion exposure, it is acceptable if the vibrations attendant with the recovery operation are large and, consequently, the recovery power of theliquid recovery mechanism20 may be made larger than during immersion exposure.
• In addition, if theliquid1 on the substrate P is not totally recovered after the completion of an immersion exposure, then it is acceptable, for example, to move the substrate stage PST that supports the substrate P so that it is disposed at a position spaced apart from the projection optical system PL, specifically, below the blowingapparatus41, and then to blow the gas against the substrate P and recover the blown off liquid1 by the stageliquid recovery apparatus30. Of course, this operation of blowing the gas can also be performed against theauxiliary plate57, the surface of theZ stage52 on the outer side of theauxiliary plate57, and the like, and not just against the substrate P. In this case as well, the residual adhered liquid1 can be satisfactorily removed by blowing the gas intermittently (or while varying the flow speed).
• In other words, although the firstliquid removing apparatus40 removes theliquid1 remaining on thereference member7, it is also possible to remove theliquid1 remaining on the substrate stage PST on components other than thereference member7. For example, in the case of a state wherein, during immersion exposure, theliquid1 flows out or scatters to the outer side of the substrate P and is disposed on the substrate stage PST (Z stage52), then the firstliquid removing apparatus40 can remove theliquid1 thereon after the exposure of the substrate P is complete. In this case, theliquid1 that is blown off by the blowingapparatus41 of the firstliquid removing apparatus40 may be recovered by theliquid absorbing member31 disposed in the groove part (recovery port)33 of the stageliquid recovery apparatus30.
• In addition, thenozzle part43 of the blowingapparatus41 may be provided movable with respect to the substrate stage PST in advance, and the liquid1 that flowed to the outer side of the substrate P may be recovered during or after the exposure thereof.
• As explained above, a turbulent flow is formed on the surface of themovable mirror55 by blowing the gas, either intermittently or while varying the flow speed, against the movable mirror55 (or reference member7) that is disposed in the vicinity of the image plane of the projection optical system PL, and it is therefore possible to satisfactorily remove theunnecessary liquid1 adhering on themovable mirror55. Furthermore, vibrating themovable mirror55, in parallel with the operation of blowing the gas, promotes the removal of the liquid1 adhering on themovable mirror55, which enables the satisfactory removal of thatliquid1.
• Furthermore, if the control apparatus CONT in the present embodiment has determined, based on the measurement result of thelaser interferometer56, that the liquid1 scattered from the substrate P has adhered to themovable mirror55, then, without waiting for the completion of the exposure of all shot regions S1-S11 on one substrate P, the liquid removing process is performed immediately in the middle of those exposures (in the time period after the exposure of the sixth shot region S6 until the start of the exposure of the seventh shot region S7). Meanwhile, even if theliquid1 adheres to themovable mirror55, and the amount of reflected light therefrom that is received by thelaser interferometer56 decreases, it is possible to measure the position of the substrate stage PST if the amount of light received is maintained at greater than or equal to a prescribed value (greater than or equal to a threshold value), which is predetermined by, for example, the performance of thelaser interferometer56. Consequently, even if, for example, theliquid1 adheres to themovable mirror55 during the exposure of one substrate P, the control apparatus CONT may perform the liquid removing process by the secondliquid removing apparatus90 after completing the exposure of all of the short regions S1-S11 on that one substrate P. In other words, when sequentially exposing a plurality of substrates P, the control apparatus CONT may remove theliquid1 adhering to themovable mirror55 by using the secondliquid removing apparatus90 during the time period after the completion of the exposure of the eleventh shot region S11 on one substrate (first substrate) P until the start of the exposure of the first shot region S1 on the next substrate (second substrate) P.
• In addition, in the abovementioned embodiment, the control apparatus CONT assesses whether theliquid1 is adhering to themovable mirror55 based on the measurement relief of the laser interferometer56 (the light receiving result), and then determines the timing by which to perform the liquid removing process based on the result of that assessment. On the other hand, if only a slight amount of theliquid1 is adhering to themovable mirror55 as discussed above, then it is possible to measure the position of the substrate stage PST. Accordingly, the control apparatus CONT may perform the process of removing the liquid by the secondliquid removing apparatus90 periodically at a predetermined prescribed time interval (or at intervals of a prescribed number of processed substrates) without relying on the measurement result of thelaser interferometer56.
• As discussed above, the liquid removing operation for removing theliquid1 that adheres to themovable mirror55 can be performed during the exposure operation of one substrate P. Here, the liquid removing operation in the abovementioned embodiment is performed between the exposure of the sixth shot region S6 and the exposure of the seventh shot region S7, and the exposure operation is temporarily interrupted during that liquid removing operation. However, as depicted inFIG. 8, a constitution is also possible wherein theliquid1 is removed by the blow out nozzles91 (and the second liquid recovery mechanism100) accessing (approaching in the X axial direction) themovable mirror55 of the substrate stage PST, and blowing the gas against thatmovable mirror55 while continuing the exposure operation of that substrate P (in parallel with the exposure operation of the substrate P). At that time, the blown outnozzles91 are provided on both sides of thelaser interferometer56, and can consequently access themovable mirror55 and blow the gas thereagainst, while moving synchronized to thatmovable mirror55 in the X axial direction, without interfering with the optical path of the measurement beam of thelaser interferometer56. Furthermore, it is preferable to set the flow speed of the blown gas, and the like, to an optimal value that does not reduce the position measurement accuracy, without driving the vibrating apparatus, so that the position measurement accuracy of thelaser interferometer56 is not reduced by the vibration of themovable mirror55 due to the liquid removing operation. In addition, if the exposure operation and the liquid removing operation are performed in parallel, then the liquid removing operation may be, in addition to blowing the gas, the operations of suctioning the liquid or supplying the dry gas.
• Furthermore, when theliquid1 has adhered to themovable mirror55, the control apparatus CONT can also blow the gas against the entire area of the surface (the reflecting surface) of themovable mirror55 from the blow outnozzles91, and can also blow the gas against part of the area where theliquid1 is adhered. If theliquid1 adheres to part of the area of themovable mirror55, then the amount of the reflected light received will decrease only when the measurement beam is irradiated upon that partial area, and therefore the control apparatus CONT can derive the area of themovable mirror55 where theliquid1 is adhered based on the amount of the reflected light of the measurement beam, which is irradiated by thelaser interferometer56, that is received from themovable mirror55. Accordingly, gas may be blown against only the partial area of themovable mirror55. In so doing, it is possible to reduce the work time for blowing the gas. Thus, based on the measurement result of thelaser interferometer56, the control apparatus CONT can determine the timing at which the liquid removing process is performed by the secondliquid removing apparatus90, and can also determine the area at which the secondliquid removing apparatus90 performs the liquid removing process.
• Furthermore, to remove theliquid1 adhering to themovable mirror55 in the abovementioned embodiment, the vibration operation by thepiezoelectric film92 is performed in parallel with the operation of blowing the gas from the gas blow outports91A; however, theliquid1 adhering to themovable mirror55 can be removed by performing only the vibration operation or the gas blowing operation. In particular, because the reflectingsurface55S of themovable mirror55 is provided perpendicular (or substantially perpendicular) to the horizontal plane, it is possible to satisfactorily remove theliquid1 by the self weight (self weight action) of theliquid1 by performing either the vibration operation or the gas blowing operation.
• Furthermore, there is a possibility that error will arise, for example, in the orthogonality with respect to the reference coordinate system within the XY plane if, for example, themovable mirror55 becomes mispositioned when vibrated, and the substrate stage PST is then moved based on the position measurement result, which is based on the measurement beam that was irradiated upon that mispositionedmovable mirror55. Consequently, it is preferable to periodically perform a calibration process that compensates the substrate stage position measurement error, including orthogonality error.
• To perform the liquid removing process after the exposure of the sixth shot region S6 in the abovementioned embodiment, the control apparatus CONT moves the substrate stage PST so that themovable mirror55 accesses the vicinity of the blow out nozzles91 (the liquid removing process position). However, the present invention is not limited thereto, and it is also possible to provide a movement mechanism to the blow out nozzles and the drain member102 (second liquid recovery mechanism100) so that they can access themovable mirror55 without moving the substrate stage PST after exposing the sixth shot region S6. Alternatively, thedrain member102, along with the substrate stage PST and the blow outnozzles91, may be moved.
• In the abovementioned embodiment, the vibratingapparatus92, which vibrates themovable mirror55, is made of a piezoelectric film that is attached (affixed) to themovable mirror55, but a constitution is also possible wherein it is not attached thereto. For example, as depicted inFIG. 9, a vibratingapparatus121, such as a piezoelectric device, is attached to the front part of anarm mechanism120, which is driven to bring thepiezoelectric device121 affixed to the front part of thearm mechanism120 into contact with themovable mirror55; further, when vibrating themovable mirror55 in order to remove theliquid1, themovable mirror55 can be vibrated by applying a voltage to thepiezoelectric device121 to drive it in a state wherein themovable mirror55 is made to contact thepiezoelectric device121. After the liquid removing operation is complete, thepiezoelectric device121 is withdrawn by thearm mechanism120. Furthermore, a constitution is also possible wherein thearm mechanism120 and thepiezoelectric device121 attached to the front part thereof are disposed on both sides of thelaser interferometer56.
• In the abovementioned embodiment, a vibrating apparatus (a piezoelectric device) is attached to every component, such as themovable mirror55 and thereference member7, and vibrated, but the entire substrate stage PST, which supports all of these components, may be vibrated by a vibrating apparatus during the liquid removing process, or may be jogged (vibrated) by driving the substrate stage drive apparatus PSTD. In so doing, it is possible to promote the removal of the liquid1 adhering on theauxiliary plate57 and the like—not just to themovable mirror55, thereference member7, and the like.
• In the abovementioned embodiment, the liquid adhering to themovable mirror55 is removed by blowing the gas thereagainst, but it is also possible to remove theliquid1 adhering to themovable mirror55 by using asuction apparatus130, as depicted inFIG. 10. InFIG. 10, thesuction apparatus130 includes asuction part131, which includes a tank and a pump, and asuction nozzle132, which is connected to thesuction part131. Furthermore, asuction port133 of thesuction nozzle132 is disposed proximate to themovable mirror55. When removing theliquid1 adhering to themovable mirror55, the control apparatus CONT drives thesuction part131 to suck and recover theliquid1 on themovable mirror55 through thesuction nozzle132. Furthermore, if using thesuction apparatus130 to recover theliquid1, the vibration operation may be performed in parallel by the vibratingapparatus92, and it is also acceptable to perform only the suction operation by thesuction apparatus130.
• Alternatively, it is also possible to remove theliquid1 adhering to themovable mirror55 using adrying apparatus160, as depicted inFIG. 11. InFIG. 11, the dryingapparatus160 includes acover member161, which covers themovable mirror55, and a drygas supply part162, which supplies dry gas to the space inside thecover member161. The drygas supply part162 supplies dry gas to the space inside thecover member161, which covers themovable mirror55, through aconduit163. This promotes the vaporization of the liquid1 adhering to themovable mirror55, which removes theliquid1.
• Furthermore, in the abovementioned embodiment, the vibrating apparatus was explained using a piezoelectric device, such as piezoelectric actuator, as an example, but it is also possible to use other actuators that use Lorentz's force, such as a voice coil motor, as the vibrating apparatus.
• FIG. 12 is a schematic oblique view that depicts another embodiment of the vibrating apparatus that vibrates themovable mirror55. In the present embodiment, themovable mirror55 does not have a groove part and is attached to the end part of theZ stage52. InFIG. 12, astep part52D, which is L shaped when viewed in a side view, is formed at the end part of theZ stage52 on the +X side, and extends in the Y axial direction. Furthermore, alower part area55G, which is on the surface of themovable mirror55 that opposes theZ stage52, is connected to theZ stage52, and aspacer28 is formed between anupper part area55H and theZ stage52. Namely, the upper part of themovable mirror55, the lower part of which is connected to theZ stage52, constitutes a free end of the vibration.
• Piezoelectric devices17 (17A,17B), which serve as vibrating apparatuses, are attached at a plurality of prescribed positions of theupper part area55H, which is on the surface of themovable mirror55 that opposes theZ stage52. Furthermore, other actuators, such as voice coil motors, may be used as the vibrating apparatuses. In the present embodiment, thepiezoelectric devices17A,17B are respectively attached to both end parts of theupper part area55H of themovable mirror55 in the longitudinal direction. Furthermore,weight members19A,19B are connected to thesepiezoelectric devices17A,17B respectively. At this point, thepiezoelectric devices17, which are affixed to themovable mirror55, and theweight members19 are spaced apart from theZ stage52. Thepiezoelectric devices17A,17B vibrate themovable mirror55 by expanding and contracting in the direction depicted by the arrows x1, x2 in the figure. At this point, theweight members19A,19B are connected to thepiezoelectric devices17A,17B, which amplifies the vibration force (momentum).
• In the present embodiment, the control apparatus CONT generates a traveling wave in themovable mirror55 by vibrating such at a plurality of (two) positions using the twopiezoelectric devices17A,17B, respectively. Specifically, a traveling wave is generated in themovable mirror55 by generating high frequencies, out of phase and at the same wavelength, at each of the positions where the twopiezoelectric devices17A,17B are attached.
• For example, it is possible to express the standing wave U.sub.0 generated at a given single point on themovable mirror55 by the sum of the traveling wave and the reverse wave. −.times. EQUATION .times. .times. 1 .times. −.times. .times. .times. U 0=A 0 .times. sin .times. .times. 2 .times. .pi. .function. (x/.lamda. −t/T)+A 0 .times. sin .times. .times. 2 .times. .pi. .function. (x/.lamda. +t/T)=2 .times. A 0 .times. sin .times. .times. 2 .times. .pi. .times. .times. x/.lamda. cos .times. .times. 2 .times. .times. .pi. .times. .times. t/T (1) ##EQU1## where:
• A.sub.0: Amplitude
• .lamda.: Wavelength
• T: Period
• x: Arbitrary point
• t: Arbitrary time
• The traveling wave U is generated by adding two of the standing waves in equation (1) and shifting the phase of one of them. −.times. EQUATION .times. .times. 2 .times. −.times. .times. .times. U=A .times. .times. sin .times. .times. 2 .times. .pi. .times. .times. x/.lamda. cos .times. .times. 2 .times. .pi. .times. .times. t/.lamda. +A .times. .times. sin .times. .times. 2 .times. .pi. function. (x+.alpha.)/.lamda. cos .times. .times. 2 .times. .pi. function. (2 .times. .pi. .times. .times. t/T+.beta.)=A .times. .times. sin .times. .times. 2 .times. .pi. function. (x /.lamda. −t/T) (2) ##EQU2## where:
• A: Amplitude
• .alpha.: Positional offset
• .beta.: Phase offset
• The control apparatus CONT generates the traveling wave in themovable mirror55 by using each of the twopiezoelectric devices17A,17B to vibrate themovable mirror55 so that the above equation (2) is satisfied. In so doing, it is possible to satisfactorily remove theliquid1 adhering to themovable mirror55.
• The following explains another embodiment of the liquid removing apparatus. In the following explanation, constituent parts that are identical or equivalent to those in the embodiment discussed above are assigned the identical symbol, and the explanation thereof is simplified or omitted.
• FIG. 13 depicts another embodiment of the firstliquid removing apparatus40. InFIG. 13, the firstliquid removing apparatus40 includes asuction apparatus81, which sucks the liquid1 adhering on thereference member7. Thesuction apparatus81 includes asuction part81A, which includes a tank and a pump, and asuction nozzle82 connected to thesuction part81A. Furthermore, asuction port82A of thesuction nozzle82 is disposed proximate to thereference member7. When removing theliquid1 remaining on thereference member7, the blowingapparatus41 blows gas thereagainst, and thesuction apparatus81 sucks theliquid1 on thereference member7.
• Furthermore, in the example explained referencingFIG. 13, the blowingapparatus41 and thesuction apparatus81 were provided in combination to the firstliquid removing apparatus40, but a constitution is also acceptable wherein just thesuction apparatus81 is provided. Thesuction apparatus81 sucks, by thesuction port82A, theliquid1 remaining on thereference member7, and thisliquid1 can thereby be removed (recovered). In addition, it is possible, of course, to perform the vibration operation by thepiezoelectric device43B in parallel with the suction operation by thesuction apparatus81. Furthermore, thenozzle part82 of thesuction apparatus81 may be provided movable with respect to the substrate stage PST, and the liquid1 that flows to the outer side of the substrate P may be recovered during or after the exposure thereof.
• FIG. 14 is a cross sectional view that depicts another embodiment of the firstliquid removing apparatus40. As depicted inFIG. 14, the firstliquid removing apparatus40 includes acover member84, which covers thereference member7, and a drygas supply part85, which supplies dry gas to the space inside thecover member84. The drygas supply part85 supplies dry gas to the space inside thecover member84, wherein thereference member7 is disposed, through aconduit86. This promotes the vaporization of theliquid1 remaining on thereference member7, which removes theliquid1.
• FIG. 15 depicts an aspect of thelight receiving devices8 wherein theliquid1 adhering to light transmittingmember8A, which is provided on the substrate stage PST, is removed. In the present embodiment, thelight receiving device8 is a sensor (AIS sensor) that measures the imaging characteristics adjustment information in order to compensates for changes in the imaging characteristics of the projection optical system PL by receiving the light (exposure light) irradiated through the projection optical system PL to the image plane side (substrate P side) thereof, and measuring the aerial image of a measurement mark through the projection optical system PL. Thelight receiving device8 includes: thelight transmitting member8A, which is provided on the substrate stage PST (Z stage52), that patterns a light shielding film on the surface of the glass plate, and wherein theslit part8S, which is a light transmitting part, is formed as the center part; a condenseroptical system8C, which is embedded in theZ stage52 and whereupon the light that passed through theslit part8S of thelight transmitting member8A is irradiated; and alight receiving element8B that receives the light that passed through the condenseroptical system8C. Furthermore, a relay optical system is provided, for example, between the condenseroptical system8C and thelight receiving element8B, and thelight receiving element8B can also be disposed on the outer side of theZ stage52.
• When measuring the serial image by thelight receiving device8, it is conceivable to perform an operation wherein theliquid1 is filled between the projection optical system PL and thelight transmitting member8A of thelight receiving device8 in a state wherein the projection optical system PL and thelight transmitting member8A are mutually opposed, and the light (exposure light) is irradiated upon thelight receiving device8 through the projection optical system PL and theliquid1. After the measurement of the aerial image through theliquid1 is complete, the control apparatus CONT moves the substrate stage PST to dispose thelight transmitting member8A (light receiving device8) below thenozzle part43 of the firstliquid removing apparatus40. Thelight transmitting member8A is supported in anaperture part52C, which is formed in theZ stage52, and a vibratingapparatus8E is provided at a prescribed position outside of theslit part8S on alower surface8K of thelight transmitting member8A. The vibratingapparatus8E includes a piezoelectric device, and the control apparatus CONT vibrates thelight transmitting member8A using thispiezoelectric device8E by applying a prescribed voltage thereto.
• Theliquid absorbing member142, which recovers the liquid1 that was removed from thelight transmitting member8A by the firstliquid removing apparatus40 is provided on theZ stage52 at a position adjacent to thelight transmitting member8A. Thelight absorbing member142 is provided at a position opposing the gas blow outport43A of thenozzle part43 so that thelight transmitting member8A is interposed therebetween. Theliquid absorbing member142 is disposed in agroove part144, which is a recovery port provided in theZ stage52. Like theliquid absorbing member31 of the stageliquid recovery apparatus30, theliquid absorbing member142 is made of a porous material, e.g., porous ceramics, sponge, or the like, and can hold a prescribed amount of theliquid1.
• The control apparatus CONT blows off and removes theliquid1 remaining on and adhering to thelight transmitting member8A by blowing gas thereagainst via thenozzle part43 of the firstliquid removing apparatus40. The blown offliquid1 is held (recovered) by theliquid absorbing member142, which is disposed at a position opposing the gas blow outport43A of thenozzle part43.
• Furthermore, while using thepiezoelectric device8E to vibrate thelight transmitting member8A, the gas from the gas blow outport43A of thenozzle part43 is blown against thatlight transmitting member8A. The vibration of thelight transmitting member8A promotes the removal (shaking off) of theliquid1, enabling it to be satisfactorily removed from thelight transmitting member8A by the blowing of the gas. In addition, even in this case, the gas may be intermittently blown against thelight transmitting member8A.
• Apassageway145, which is continuous with thegroove part144, is formed inside theZ stage52, and the bottom part of theliquid absorbing member142, which is disposed in thegroove part144, is connected to thepassageway145. Thepassageway145, which is connected to thegroove part144 wherein theliquid absorbing member142 is disposed, is connected to one end of aconduit146, which is provided external to theZ stage52. On the other hand, the other end of theconduit146 is connected to apump149, which is a suction apparatus, through aconduit148 that has atank147, which is provided external to theZ stage52, and avalve148A. Adischarge passageway147A is provided to thetank147, and theliquid1 is discharged from thedischarge passageway147A when a prescribed amount has accumulated. Furthermore, the control apparatus CONT drives thegas supply part41A of the firstliquid removing apparatus40 and drives thepump149, which collects the liquid1 that was recovered by theliquid absorbing member142 so that it is sucked into thetank147.
• Furthermore, the light receiving device8awas explained by using as an example a space image measuring sensor for measuring the imaging characteristics adjustment information of the projection optical system PL, but, for example, an illumination intensity sensor that detects the illumination intensity of the exposure light EL irradiated to the image plane side of the projection optical system PL, or an illumination intensity uniformity sensor for measuring the illumination intensity distribution of the projection area AR1, may also be used as thelight receiving device8.
• The following explains the thirdliquid removing apparatus60, which removes theliquid1 remaining on theoptical element2 at the front part of the projection optical system PL, the lens cell LS that holds theoptical element2, and the like, referencingFIG. 16. InFIG. 16, the thirdliquid removing apparatus60 includes a blowingapparatus61 that blows gas against theoptical element2, which constitutes the front component of the projection optical system PL, the lens cell LS that holds theoptical element2, and the like. Arecovery apparatus62 recovers the liquid remaining at the front of the projection optical system PL and that is blown off and drops due to the blowing of the gas by the blowingapparatus61. The blowingapparatus61 includes agas supply part63 and anozzle part64, which is connected to thegas supply part63 and provided to a recessedpart64B of theZ stage52, and the gas blow outport64A of thenozzle part64 can be disposed in the vicinity of the front of the projection optical system PL facing upward. Meanwhile, therecovery apparatus62 includes: the recovery port (groove part)66, which is provided to theZ stage52; theliquid absorbing material65, which is disposed in therecovery port66 and is made of a porous material; apassageway67, which is formed inside theZ stage52 and is continuous with thegroove part66; aconduit68, which is provided external to theZ stage52 and one end of which is connected to thepassageway67; atank69, which is connected to the other end of theconduit68 and is provided external to theZ stage52; and apump71, which is a suction apparatus, connected to thistank69 through aconduit70 that has avalve70A. Adischarge passageway69A is provided to thetank69, and theliquid1 is discharged from thedischarge passageway69A when a prescribed amount has accumulated. Furthermore, in therecovery apparatus62, thepump71 is driven and collects the liquid1 that was recovered by theliquid absorbing material65 so that it is sucked into thetank69.
• In the present embodiment, the gas blow outport64A of thenozzle part64 of the blowingapparatus61 is a slit shape, wherein its longitudinal direction is set to the Y axial direction (refer toFIG. 3), and therecovery port65 of therecovery apparatus62 is rectangularly formed, wherein its longitudinal direction is set to the Y axial direction, at a position adjacent to the gas blow outport64A on the +X side. Furthermore, after the exposure of the substrate P is complete, the thirdliquid removing apparatus60 removes theliquid1 remaining not only on the front of the projection optical system PL, which contacts theliquid1 in the immersion area AR2 during the exposure of the substrate P, but also theliquid1 remaining on thesupply nozzles13 of theliquid supply mechanism10 and therecovery nozzles23 of theliquid recovery mechanism20.
• After the immersion exposure of the substrate P is complete, the control apparatus CONT recovers theliquid1 on the substrate P using theliquid recovery mechanism20. Furthermore, after the recovery of theliquid1 on the substrate P by theliquid recovery mechanism20 is complete, the control apparatus CONT moves the substrate stage PST so that the thirdliquid removing apparatus60 is disposed below the projection optical system PL. Furthermore, the thirdliquid removing apparatus60 blows gas, from the diagonal direction, from thenozzle part64 of the blowingapparatus61 against the front of the projection optical system PL, and thereby blows off and removes theliquid1 remaining thereon. At this time, theliquid1 can be more satisfactorily removed by blowing the gas intermittently.
• The blown offliquid1 falls and is recovered in therecovery port66, wherein theliquid absorbing material65 of therecovery apparatus62 is disposed. At this point, the control apparatus CONT drives the thirdliquid removing apparatus60 while moving the substrate stage PST, for example, in the X axial direction orthogonal to the longitudinal direction (Y axial direction) of the gas blow outport64A and therecovery port65. In so doing, the gas is blown against the front of the projection optical system PL and, of course, thesupply nozzles13 of theliquid supply mechanism10 and therecovery nozzles23 of theliquid recovery mechanism20 disposed at the circumference of the front of the projection optical system PL, and theliquid1 remaining on thesesupply nozzles13 andrecovery nozzles23 can thereby be removed.
• In addition, the gas may also be blown against theoptical element2 at the front part of the projection optical system PL while vibrating such. Theoptical element2 is held by the lens cell LS, and the lens cell LS and the lens barrel PK of the projection optical system main body MPL are coupled by a plurality (for example, six)link parts151, which have actuators (vibrating apparatuses), such as voice coil motors and piezoelectric devices. The control apparatus CONT can vibrate the lens cell LS and theoptical element2 held thereby by driving the abovementioned actuators, which are built into thelink parts151. Furthermore, by constituting a parallel link mechanism by the provision of a plurality oflink parts151, each having a built-in actuator, it is possible to absorb/remove the vibrations that transmit to theoptical element2 through the liquid1 during the immersion exposure of the substrate P by driving the abovementioned parallel link mechanism.
• As explained above, by removing theliquid1 remaining on the front of the projection optical system PL, which contacts theliquid1 in the immersion area AR2 during exposure, on thesupply nozzles13, and on therecovery nozzles23, it is possible to suppress problems, such as theliquid1, which remains on the front of the projection optical system PL and the like, falling and causing environmental changes that adversely impact the peripheral apparatuses, even if, for example, the substrate stage PST moves from below the projection optical system PL (the exposure process position) to the position where the substrate P is loaded and unloaded (the substrate exchange position). In particular, it is possible to suppress the occurrence of adhered residue (water mark) by ensuring that theliquid1 does not remain on theoptical element2 at the front of the projection optical system PL.
• Furthermore, by providing the thirdliquid removing apparatus60 to the substrate stage PST, it is possible, if the thirdliquid removing apparatus60 is driven while moving the substrate stage PST, to blow gas against the projection optical system PL, the supply nozzles, and the recovery nozzles while scanning the thirdliquid removing apparatus60 without providing a new actuator. In addition, the liquid removing operation (gas blowing operation) and the stage movement operation can be performed simultaneously, which can improve time efficiency, by performing the operation of blowing the gas by the thirdliquid removing apparatus60 while moving the substrate stage PST from the exposure process position to the substrate exchange position after the immersion exposure is complete. The thirdliquid removing apparatus60 can be provided in advance at a position at which it passes below the projection optical system PL while the substrate stage PST moves from the exposure process position to the substrate exchange position.
• Furthermore, it is also possible to attach a vibrating apparatus, such as a piezoelectric device, to each of thesupply nozzles13 andrecovery nozzles23, and to vibrate such to remove the liquid.
• FIG. 17 andFIG. 18 are modified examples of the thirdliquid removing apparatus60. As depicted inFIG. 17, alarge groove part72 may be formed in theZ stage52, and thenozzle part64 of the blowingapparatus61 and the passageway (recovery port)67 of therecovery apparatus62 may be disposed in thegroove part72. Furthermore, in the example depicted inFIG. 17, theliquid absorbing material65 is not provided. Thus, a constitution is also possible wherein theliquid absorbing material65 is not provided. In addition, as depicted inFIG. 18, a plurality ofnozzle parts64 of the blowing apparatus61 (two in the example depicted inFIG. 18) may be provided inside thegroove part72. As in the examples depicted inFIG. 17 andFIG. 18, by providing agroove part72 larger than the front of the projection optical system PL and disposing thenozzle parts64 and therecovery port67 therein, thegroove part72 can suppress the scattering of theliquid1, which was blown by the gas, to the periphery. Furthermore, even in this case, the control apparatus CONT can satisfactorily remove theliquid1 by intermittently blowing the gas.
• Alternatively, as depicted inFIG. 19, acover member73 can also be provided around the gas blow outport64A of thenozzle part64 and therecovery port66 in order to prevent the scattering of theliquid1, which was blown by the gas, to the surrounding area. Thecover member73 depicted inFIG. 19 is formed in a U shape in a plan view, can dispose within it the front of the projection optical system PL, and is constituted so that the front of the projection optical system PL can go into and out of thecover member73 from the open side of the U shape. Furthermore, by aligning the longitudinal direction of thecover member73 with the movement direction (X axial direction) of the substrate stage PST, and by providing the gas blow outport64A and therecovery port66 so that their longitudinal direction is set to the Y axial direction inside thecover member73, it is possible to efficiently remove the liquid, while preventing the scattering thereof, in one scanning motion.
• Furthermore, it is also possible to recover theliquid1 that flowed to the outer side of the substrate P during the exposure thereof through therecovery port65 of therecovery apparatus62 of the thirdliquid removing apparatus60. At this time, it is preferable to provide, in advance, a plurality ofrecovery ports65 of therecovery apparatus62 at prescribed intervals around the substrate P.
• FIG. 20 is a schematic drawing that depicts blow out nozzles that constitute the liquid removing mechanism, which is provided at the substrate exchange position (load and unload position). InFIG. 20, the substrate stage PST moves between an exposure process position A and a substrate exchange position B. After the process of exposing the substrate P at the exposure process position A is complete, the control apparatus CONT moves the substrate stage PST, which holds the substrate P that was exposure processed, to the substrate exchange position B. Then, the control apparatus CONT intermittently blows the gas from the blow outnozzles171 against themovable mirrors55 of the substrate stage PST, which has moved to the substrate exchange position B. In so doing, theliquid1, which scattered from the substrate P during the exposure and adhered to themovable mirrors55, can be removed at the substrate exchange position B. Furthermore, a liquid recovery mechanism that has a drain member, as explained referencingFIG. 6, is also provided at the substrate exchange position B, and the liquid1 removed from eachmovable mirror55 is recovered by the liquid recovery mechanism. Furthermore, after (or before) the work of removing theliquid1 adhering to eachmovable mirror55, a substrate transport apparatus (not shown) unloads the substrate P, for which the exposure process was completed, from the substrate stage PST and loads an unexposed substrate P thereon.
• FIG. 21 is a side view that depicts an embodiment wherein a shield member (or eaves member)180 is provided to the upper side of themovable mirror55 in order to prevent the adherence of the liquid1 thereto. InFIG. 21, themovable mirror55 is attached to the side part of the Z stage52 (substrate stage PST). Furthermore, theshield member180 is attached to the upper surface of theZ stage52 so that it partially protrudes to the outer side thereof. Themovable mirror55 is shielded by providing theshield member180, and the liquid1 consequently does not adhere to themoveable mirror55 even if, for example, theliquid1 scatters from the substrate P to the outer side thereof.
• The upper surface of theshield member180 and the surface of theauxiliary plate57 are at substantially the same height. There is a gap of approximately 0.1-1 mm between theshield member180 and theauxiliary plate57, and virtually none of the liquid1 flows into the gap due to the surface tension thereof. Because the movable mirror55 (reflectingsurface55a) is provided below theshield member180, a measuring light56afrom theinterferometer56 passes below theshield member180, which moves together with the substrate stage PST, and impinges the reflectingsurface55aof themovable mirror55. The upper end of the movable mirror55 (reflectingsurface55a) is positioned below the immersion area AR2, but theliquid1 does not adhere to the reflectingsurface55aof themovable mirror55, which is shielded by the protruding part of theshield member180.
• Theshield member180 is a plate shaped member and at least the upper surface thereof is liquid repellant. In the present embodiment, theshield member180 is made of a liquid repellant material, e.g., polytetrafluoroethylene, or the like. Furthermore, the surface (upper surface) of the plate shaped member, which serves as theshield member180, is made of, for example, a prescribed metal material or a synthetic resin material, and may be given a surface treatment, such as coating it with a liquid repellant material, e.g., a fluorine compound. By making the upper surface of theshield member180 liquid repellant, thescattered liquid1 is shaken off, even if it adheres to the upper surface of theshield member180, and is easily recovered by theprocessing mechanism101, which has thedrain member102 disposed below theshield member180, without pooling on the shield member180 (on the substrate stage PST).
• The end surface and the lower surface—not just the upper surface—of theshield member180 can also be treated in advance to make them liquid repellant. In addition, agroove180amay be provided in the lower surface of theshield member180, in the vicinity of the end part thereof, over all or part of the reflecting surface of themovable mirror55 in the longitudinal direction thereof. Thisgroove180acan prevent the adherence of theliquid1, which comes around from the end of theshield member180 to themovable mirror55.
• In the present embodiment, the size of thedrain member102, which constitutes the secondliquid removing mechanism100, is set in accordance with the size of theshield member180, a distance H between theshield member180 and thedrain member102, and the travel speed V of the substrate stage PST that supports theshield member180. More specifically, when, for example, the substrate stage PST moves in the +X direction at the speed V and then stops at a liquid removal process position SH, a distance L1 between the front part of theshield member180 and the end part of thedrain member102 on the +X side is set in accordance with the travel speed V of the substrate stage PST and the distance H between theshield member180 and thedrain member102 in the Z axial direction. Namely, if a droplet of theliquid1 is disposed on the upper surface of theshield member180 at the front part as depicted inFIG. 21, then the substrate stage PST moves in the +X direction at the speed V and then stops at the liquid removal process position SH. Using that stopped time as a reference, the position x of the droplet in the X axial direction after time t is defined by x=Vt, and the position z in the Z axial direction is defined by z=H−(gt.sup.2)/2 (wherein g if the gravitational acceleration). Accordingly, it is possible to derive the minimum value of the size L1 of thedrain member102 from these two equations so that the droplet of theliquid1, which dropped fromshield member180, can be recovered by thedrain member102. At this time, the upper surface of theshield member180 is liquid repellant, and therefore theliquid1 adhering to that upper surface is smoothly separated therefrom and drops to thedrain member102.
• In addition, as depicted inFIG. 21, a vibratingapparatus182, which includes a piezoelectric device and the like, can be attached to theshield member180. Vibrating theshield member180 with the piezoelectric device (vibrating apparatus)182 promotes the removal of the liquid1 from theshield member180. In addition,piezoelectric devices182 may be provided at a plurality of prescribed positions so that they generate a traveling wave in theshield member180.
• Furthermore, thedrain member102 used in the present embodiment may be disposed not only at the lower part of themovable mirror55, but also at the bottom part of theZ stage52 around the entire circumference thereof. For example, the secondliquid removing mechanism100 explained inFIG. 6 may be provided on theXY stage53 that supports theZ stage52, and thedrain member102 of this second liquid removingmechanism100 may be disposed so that it surrounds theZ stage52. In this case, as depicted in the figure, the surface at which thedrain member102 receives the liquid is set so that it is positioned below (in the −Z direction) the holding surface at which theZ stage52 holds the substrate P (e.g., the support surface of the substrate holder), the aperture surface of the groove part (recovery port)33 that constitutes part of theliquid recovery apparatus30 formed in the upper surface of theauxiliary plate57 and in theZ stage52, and the like. In addition, the end part of the holding surface of the Z stage52 (including the end part of the movable mirror55) is positioned in advance above the part of thedrain member102 that receives the liquid. According to such a constitution, the liquid, which was not completely recovered by theliquid recovery apparatus30 and that dropped from the end part of theZ stage52, is received by thedrain member102, and that liquid can be removed or recovered by the liquid removingmechanism100. In addition, the liquid, which dropped from theoptical element2 at the front of the projection optical system PL and from the lens cell LS that holds theoptical element2, is received by thisdrain member102 and can be removed or recovered.
• Furthermore, thedrain member102 can also prevent the liquid from dropping on and adhering to theXY stage53. Consequently, it is possible to prevent the scattering of the liquid to locations where it is undesirable for such to adhere, such as the drive parts of theZ stage52 and theXY stage53, the surface of thebase54, and the like. Accordingly, it is possible to suppress a decrease in the positioning accuracy of the substrate and to form the desired pattern thereon with good accuracy. Furthermore, thedrain member102 may also be provided on the upper surface of the XY stage53 (on the side of theXY stage53 with the surface opposing the Z stage52), so that it acts like a shield for the lower surface, and the side part of the end surface, of the Z stage52 (on the side of theZ stage52 with the surface opposing the XY stage).
• As discussed above, theliquid1 in the present embodiment includes pure water. Pure water is advantageous because it can be easily obtained in large quantities ar a semiconductor fabrication plant and the like, and because pure water has no adverse impact on the optical elements (lenses), the photoresist on the substrate P, and the like. In addition, because pure water has no adverse impact on the environment and has an extremely low impurity context, it can also be expected to have the effect of cleaning the surface of the substrate P and the surface of the optical element provided on the front surface of the projection optical system PL.
• Further, because the refractive index n of pure water (water) for the exposure light EL that has a wavelength of approximately 193 nm is said to be substantially 1.44, the use of ArF excimer laser light (193 nm wavelength) as the light source of the exposure light EL would shorten the wavelength on the substrate P to 1/n, i.e., approximately 134 nm, thereby obtaining a high resolution. Furthermore, because the depth of focus will increase approximately n times, i.e., approximately 1.44 times, that of in air, the numerical aperture of the projection optical system PL can be further increased if it is preferable to ensure a depth of focus approximately the same as that when used in air, and the resolution is also improved from this standpoint.
• In the present embodiment, theoptical element2 is attached to the front of the projection optical system PL, and this lens can adjust the optical characteristics, e.g., aberrations (spherical aberration, coma aberration, and the like), of the projection optical system PL. Furthermore, the optical element attached to the front of the projection optical system PL may be the optical plate used to adjust the optical characteristic of the projection optical system PL. Alternatively, it may be a parallel plane plate capable of transmitting the exposure light EL.
• Furthermore, if the pressure generated by the flow of the liquid1 between the optical element at the front of the projection optical system PL and the substrate P is large, then the optical element may be rigidly fixed by that pressure so that it does not move, instead of making that optical element exchangeable.
• Furthermore, the present embodiment is constituted so that theliquid1 is filled between the projection optical system PL and the surface of the substrate P, but it may be constituted so that, for example, theliquid1 is filled in a state wherein a cover glass, including a parallel plane plate, is attached to the surface of the substrate P.
• Furthermore, although theliquid1 in the present embodiment is water, it may be a liquid other than water; for example, if the light source of the exposure light EL is an F.sub.2 laser, then the F.sub.2 laser light will not transmit through water, so it would be acceptable to use as the liquid1 a fluorine based fluid, such as perfluorinated polyether (PFPE) or fluorine based oil, that is capable of transmitting F.sub.2 laser light. In this case, the portion that contacts theliquid1 is given lyophilic treatment by, for example, forming a thin film with a substance that has a low polarity molecular structure that contains fluorine. In addition, it is also possible to use as theliquid1 one (e.g., cedar oil) that is transparent to the exposure light EL, has the highest possible refractive index, and is stable with respect to the projection optical system PL and the photoresist coated on the surface of the substrate P. In this case as well, the surface treatment is performed in accordance with the polarity of the liquid1 used.
• Furthermore, the substrate P in each of the abovementioned embodiments is not limited to a semiconductor wafer for fabricating semiconductor devices, and is also applicable to a glass substrate for a display device, a ceramic wafer for a thin film magnetic head, or a mask or original plate of a reticle (synthetic quartz, silicon wafer) used by an exposure apparatus, and the like.
• In addition to a step-and-scan system scanning type exposure apparatus (scanning stepper) that scans and exposes the pattern of the mask M by synchronously moving the mask M and the substrate P, a step-and-repeat system projection exposure apparatus (stepper) that exposes the full pattern of the mask M with the mask M and the substrate P in a stationary state and sequentially steps the substrate P is also applicable as the exposure apparatus EX. In addition, the present invention is also applicable to a step-and-stitch system exposure apparatus that partially and superimposingly transfers at least two patterns onto the substrate P.
• In addition, the present invention is also applicable to the twin stage type scanning steppers disclosed in Japanese Unexamined Patent Application, First Publication No. H10-163099 and the corresponding U.S. Pat. No. 6,341,007, Japanese Unexamined Patent Application, First Publication No. H10-214783 and the corresponding U.S. Pat. No. 6,341,007, Published Japanese Translation No. 2000-505958 of the PCT International Publication and the corresponding U.S. Pat. No. 5,969,441, and the like.
• Furthermore, the disclosures of the abovementioned Japanese publications and the corresponding U.S. patents are each hereby incorporated by reference in its entirety to the extent permitted by the national laws and regulations of the designated states (or elected states) designated by the present international patent application.
• In addition, in the embodiments discussed above, an exposure apparatus is used that locally fills liquid between the projection optical system PL and the substrate P, but the present invention is also applicable to a liquid immersion exposure apparatus that moves a stage, which holds the substrate to be exposed, in a liquid bath, as disclosed in Japanese Unexamined Patent Application, First Publication No. H06-124873.
• In addition, the disclosure of the abovementioned Japanese publication is hereby incorporated by reference in its entirety to the extent permitted by the national laws and regulations of the designated states (or elected states) designated by the present international patent application.
• The type of exposure apparatus EX is not limited to semiconductor device fabrication exposure apparatuses that expose the pattern of a semiconductor device on the substrate P, but is also widely applicable to exposure apparatuses for fabricating liquid crystal devices or displays, exposure apparatuses for fabricating thin film magnetic heads, imaging devices (CCD), or reticles and masks, and the like.
• If a linear motor is used in the substrate stage PST or the mask stage MST, as disclosed in U.S. Pat. No. 5,623,853 and U.S. Pat. No. 5,528,118, then either an air levitation type that uses an air bearing or a magnetic levitation type that uses Lorentz's force or reactance force may be used. In addition, each of the stage PST, MST may be a type that moves along a guide or may be a guideless type not provided with a guide.
• The disclosure of the abovementioned U.S. patents are each hereby incorporated by reference in its entirety to the extent permitted by the national laws and regulations of the designated states (or elected states) designated by the present international patent application.
• For the drive mechanism of each of the stages PST, MST, a planar motor may be used that opposes a magnet unit, wherein magnets are disposed two dimensionally to an armature unit, wherein coils are disposed two dimensionally, and drives each of the stages PST, MST by electromagnetic force. In this case, any one among the magnet unit and the armature unit is connected to the stages PST, MST and the other one of the magnet unit and the armature unit should be provided on the moving surface side of the stages PST, MST.
• The reaction force generated by the movement of the substrate stage PST may be mechanically discharged to the floor (ground) using a frame member so that it is not transmitted to the projection optical system PL, as recited in Japanese Unexamined Patent Application, First Publication No. H08-166475 and the corresponding U.S. Pat. No. 5,528,118.
• The disclosures of the abovementioned Japanese publication and the corresponding U.S. patent are each hereby incorporated by reference in its entirety to the extent permitted by the national laws and regulations of the designated states (or elected states) designated by the present international patent application.
• The reaction force generated by the movement of the mask stage MST may be mechanically discharged to the floor (ground) using a frame member so that it is not transmitted to the projection optical system PL, as recited in Japanese Unexamined Patent Application, First Publication No. H08-330224 and the corresponding U.S. Pat. No. 5,874,820.
• The disclosures of the abovementioned Japanese publication and the corresponding U.S. patent are each hereby incorporated by reference in its entirety to the extend permitted by the national laws and regulations of the designated states (or elected states) designated by the present international patent application.
• The exposure apparatus EX of the embodiments in the present application as described above is manufactured by assembling various subsystems, including each constituent element recited in the claims of the present application, so that a prescribed mechanical accuracy, electrical accuracy, and optical accuracy are maintained. To ensure these various accuracies, adjustments are performed before and after this assembly, including an adjustment to achieve optical accuracy for the various optical systems, an adjustment to achieve mechanical accuracy for the various mechanical systems, and an adjustment to achieve electrical accuracy for the various electrical systems. The assembly process from the various subsystems to the exposure apparatus includes the mutual mechanical connection of the various subsystems, the wiring and connection of electrical circuits, the piping and connection of the atmospheric pressure circuit, and the like. Naturally, before the assembly process, ranging from these various subsystems to the exposure apparatus, there are processes for assembling each of the individual subsystems. When the assembly process from various subsystems to the exposure apparatus has completed, a comprehensive adjustment is performed to ensure the various accuracies of the exposure apparatus as a whole. Furthermore, it is preferable to manufacture the exposure apparatus in a clean room wherein the temperature, the cleanliness level, and the like, are controlled.
• As shown inFIG. 22, a micro-device, such as a semiconductor device is manufactured by: astep201 that designs the functions and performance of the micro-device; astep202 that fabricates a mask (reticle) based on this design step, astep203 that fabricates a substrate, which is the base material of the device; asubstrate processing step204 wherein the exposure apparatus EX of the embodiments discussed above exposes a pattern of the mask onto the substrate; a device assembling step205 (including a dicing process, a bonding process, and a packaging process); an inspectingstep206; and the like.
• According to the present invention, by removing unnecessary liquid, which remained after the exposure and adhered, and unnecessary liquid, which scattered during exposure and adhered, it is possible to prevent the deterioration of the exposure accuracy due to this unnecessary liquid, and to form a desired pattern on a substrate with good accuracy.

Claims (15)

1. A stage system used in an exposure apparatus having a projection optical system, the stage system comprising:

a substrate holding member that is movable in the exposure apparatus, the substrate holding member including:

(i) a holder portion that is configured to hold a substrate to be exposed via the projection optical system through a liquid in the exposure apparatus,

(ii) an outer side surface facing in a direction radially outward with respect to the holder portion,

(iii) an edge portion having an end part of an upper surface of the substrate holding member, the edge portion being provided below an end surface of the projection optical system, the edge portion protruding laterally beyond the outer side surface in the direction radially outward of the outer side surface with respect to the holder portion, and

(iv) a surrounding portion that surrounds the holder portion and is located between the substrate and the edge portion when the substrate is held by the holder portion.

2. The stage system according toclaim 1, wherein an upper surface of the edge portion and the upper surface of the substrate held by the holder portion are disposed in a substantially same plane.

3. The stage system according toclaim 1, wherein the edge portion is configured to hold the liquid of a liquid immersion area.

4. The stage system according toclaim 1, wherein

an optical path between a lower end surface of the projection optical system and an upper surface of the substrate is filled with the liquid of a liquid immersion area,

less than an entirety of the upper surface of the substrate is covered by the liquid immersion area during exposure of the substrate in the exposure apparatus, and

the liquid immersion area is moved relative to the substrate during the exposure.

5. The stage system according toclaim 1, wherein an upper surface of the surrounding portion is substantially in a same plane as a surface of the substrate when the substrate is held on the substrate holding member.

6. The stage system according toclaim 1, wherein

a shot area of the substrate held on the substrate holding member is exposed while moving the substrate holding member in the exposure apparatus.

7. The stage system according toclaim 1, wherein the edge portion has a groove on a lower surface of the edge portion.

8. The stage system according toclaim 1, further comprising a vibrating apparatus including a piezoelectric device attached to the edge portion.

9. The stage system according toclaim 1, further comprising a plurality of piezoelectric devices provided at a plurality of prescribed positions to generate a traveling wave in the edge portion.

10. The stage system according toclaim 1, wherein the surrounding portion and the edge portion are disposed side by side.

11. The stage system according toclaim 1, wherein a part of the edge portion projects outside the substrate holding member.

12. An exposure apparatus comprising:

a projection optical system;

a substrate holding member that is movable in the exposure apparatus, the substrate holding member including:

(i) a holder portion that is configured to hold a substrate to be exposed via the projection optical system through a liquid in the exposure apparatus,

(ii) an outer side surface facing in a direction radially outward with respect to the holder portion,

(iii) an edge portion having an end part of an upper surface of the substrate holding member, the edge portion being provided below an end surface of the projection optical system, the edge portion protruding laterally beyond the outer side surface in the direction radially outward of the outer side surface with respect to the holder portion, and

(iv) a surrounding portion that surrounds the holder portion and is located between the substrate and the edge portion when the substrate is held by the holder portion.

13. A device manufacturing method comprising:

exposing a substrate by using the exposure apparatus according toclaim 12; and

processing the exposed substrate.

14. An exposure method comprising:

holding a substrate on a substrate holding member which has a holder portion to hold the substrate;

supplying a liquid onto the substrate such that an optical path between a lower end surface of a projection optical system and an upper surface of the substrate is filled with the supplied liquid forming a liquid immersion area; and

exposing the substrate held on the substrate holding member with an exposure beam through the liquid immersion area, while moving the substrate holding member, wherein

the liquid immersion area is moved relative to the substrate during the exposure, and

the substrate holding member further includes:

an outer side surface facing in a direction radially outward with respect to the holder portion,

an edge portion having an end part of an upper surface of the substrate holding member, the edge portion being provided below an end surface of the projection optical system, the edge portion protruding laterally beyond the outer side surface in the direction radially outward of the outer side surface with respect to the holder portion, and

a surrounding portion that surrounds the holder portion and is located between the substrate and the edge portion when the substrate is held by the holder portion.

15. The exposure method according toclaim 14, further comprising vibrating the edge portion with a piezoelectric device to promote removal of the liquid from the edge portion.

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