CN215932365U - Photoetching system for super surface processing - Google Patents

Abstract

The embodiment of the application provides a photoetching system for super-surface processing, and belongs to the field of super-surfaces. The system comprises a light source, an exposure projection system and a double-sided mark alignment system; a marking unit; the double-sided mark alignment system is arranged below the exposure projection system; the double-sided mark alignment system comprises a collimated light source, a microscope system, a workbench and a control system; the workbench comprises a pose adjusting device and a carrier; the carrier is detachably connected with the pose adjusting device; the pose adjusting device is used for adjusting the position and/or the posture of the carrier; the precision of the worktable is hundreds of nanometers to micron-scale precision. The system realizes the super-surface processing through the middle-precision workbench, replaces the ultrahigh-precision workbench, and reduces the super-surface processing cost.

Description

Photoetching system for super surface processing

Technical Field

The application relates to the technical field of super surface processing, in particular to a photoetching system for super surface processing.

Background

At present, the common process for processing a super-surface is a photolithography process, in which a layer of photoresist with high photosensitivity is covered on the surface of a wafer (generally, a silicon wafer), and then light (generally, ultraviolet light, deep ultraviolet light, and extreme ultraviolet light) is irradiated on the surface of the wafer through a mask, and the photoresist irradiated by the light reacts. The irradiated/non-irradiated photoresist is then washed away with a specific solvent, and the transfer of the circuit pattern from the mask to the photoresist is achieved. And etching the silicon wafer without the protection of the photoresist after the photoetching is finished, and finally washing off the residual photoresist to realize the construction process of the super-surface nano structure on the surface of the wafer.

Existing super-surface processing uses a lithography machine for semiconductor processing. A lithography machine for semiconductor processing typically includes an ultraviolet light source, an exposure projection system, and an ultra-high precision stage. Wherein, the ultra-high precision workbench is a workbench with the precision reaching the nanometer precision.

In the super-surface processing, the cost of the super-precision workbench is high, so that the price of the photoetching machine is high, and the super-surface processing cost is high; also, the photolithography machine for semiconductor processing is designed for planar processing, and has a limitation in processing a super surface of a non-planar substrate. Therefore, there is a need for a lithography system that can process non-planar substrates at a low processing cost.

Disclosure of Invention

In order to solve the existing technical problem, the embodiment of the present application provides a lithography system for super surface processing, so as to solve the problem of high cost of super surface processing.

The embodiment of the application provides a photoetching system for super-surface processing, which comprises a light source, an exposure projection system and a double-surface mark alignment system for aligning a first surface and a second surface of a photoetching object; for double-sided exposure alignment of a super-surface lithography system, the lithography system further comprises: the marking unit is used for making an alignment mark on the photoetching object;

wherein the light source is disposed above the exposure projection system and the double-sided indicia alignment system is disposed below the exposure projection system;

the double-sided mark alignment system comprises a collimated light source, a microscope system, a workbench and a control system;

the workbench comprises a pose adjusting device and a carrier; the carrier is detachably connected with the pose adjusting device; the pose adjusting device is used for adjusting the position and/or the posture of the carrier; the precision of the workbench is hundreds of nanometers to micron-scale precision.

Optionally, the pose adjusting device comprises an X-axis linear displacement platform, a Y-axis linear displacement platform, a Z-axis linear displacement platform and a rotating platform;

the Z-axis linear displacement platform is vertically and fixedly installed with a horizontal plane;

the Y-axis linear displacement platform is connected with a displacement piece of the Z-axis linear displacement platform, and the Y-axis linear displacement platform is perpendicular to the Z-axis linear displacement platform;

the X-axis linear displacement platform is connected with a displacement piece of the Y-axis linear displacement platform, and the X-axis linear displacement platform is respectively vertical to the Y-axis linear displacement platform and the Z-axis linear displacement platform;

the rotating platform is connected with a displacement piece of the X-axis linear displacement platform;

the Z axis is perpendicular to the horizontal plane, and the X axis and the Y axis are perpendicular to the Z axis respectively.

Optionally, the maximum displacement travel of the pose adjustment apparatus is greater than the size of the lithographic object.

Optionally, the pose adjustment device has a rotational stroke of 360 °.

Optionally, the minimum rotation angle of the posture adjustment device is less than or equal to 0.1 °.

Optionally, the lithographic object comprises a planar lithographic object or a non-planar lithographic object.

Optionally, the marking unit is located on a side surface of the lithographic object near an edge.

Optionally, the marking elements are made of a material that is opaque to near infrared light.

Optionally, the marking unit includes a coarse alignment mark and a fine alignment mark.

Optionally, the shape of the marking unit comprises one or more of a cross shape, a comb shape, a rectangular shape, a circular shape, and a ring shape.

The technical scheme provided by the embodiment of the application has the advantages that at least:

according to the photoetching system for super-surface processing, the marking unit on the first surface of the photoetching object is imaged through the collimated light source, so that the marking unit is positioned in the center of the visual field of the microscope system and is photographed into an initial picture; the alignment of the second surface of the photoetching object is realized by aligning the marking unit with the marking unit in the initial picture when the second surface of the photoetching object is placed. Through the alignment of the marking units under the imaging of the collimated light wave band, the workbench with the precision of hundreds of nanometers to micron order moves through the middle precision, so that the photoetching processing of the super surface is realized; by replacing the ultra-high precision stage with a precision in the order of hundreds of nanometers to microns, the cost of the lithography system for super-surface machining is reduced, thereby reducing the cost of super-surface machining. The lithography system also enables the processing of the super-surface of a non-planar substrate by movement and/or rotation of the stage during exposure.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments or the background art of the present application, the drawings required to be used in the embodiments or the background art of the present application will be described below.

FIG. 1 is a schematic diagram illustrating an alternative configuration of a lithography system for super-surface processing according to an embodiment of the present application;

FIG. 2 is a schematic diagram illustrating alignment of a marking unit of a lithography system for super-surface processing provided by an embodiment of the present application;

FIG. 3 depicts an alternative misalignment schematic of a marking unit of a lithography system for super-surfacing provided by an embodiment of the present application;

FIG. 4 depicts a schematic diagram of yet another alternative misalignment of a marking unit of a lithography system for super-surfacing provided by an embodiment of the present application;

FIG. 5 depicts a schematic view of an alternative misalignment of a marking unit of a lithography system for super-surfacing provided by an embodiment of the present application;

FIG. 6 is a flow chart illustrating a photolithography method for super-surface processing according to an embodiment of the present application.

The reference numerals in the drawings denote:

1-a light source;

2-exposing the projection system;

31-a collimated light source; 32-a microscope system; 33-a workbench; 34-a control system;

331-pose adjusting means; 332-a carrier;

3311-X axis linear displacement platform; 3312-Y axis linear displacement stage; 3313-Z axis linear displacement stage; 3314-rotating platform;

321-a microscope objective; 322-connecting tube; 323-imaging detector;

4-a lithographic object;

5-a marking unit;

51-coarse alignment marks; 52-Fine alignment marks.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

It should be noted that, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly and may include, for example, fixed connections, removable connections, or integral connections; either mechanically or electrically: the connection may be direct or indirect via an intermediate medium, and may be a communication between the two elements. Specific meanings of the above terms in the embodiments of the present application can be understood in specific cases by those of ordinary skill in the art.

It is to be understood that although the terms first, second, third, etc. may be used herein to describe various information, such information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present application. The word "if" as used herein may be interpreted as "at … …" or "when … …" or "in response to a determination", depending on the context. The features of the following examples and embodiments may be combined with each other without conflict. The embodiments of the present application will be described below with reference to the drawings.

FIG. 1 is a schematic diagram illustrating an alternative configuration of a lithography system for super-surface processing according to an embodiment of the present application. As shown in fig. 1, the system includes a light source 1, an exposure projection system 2, and a double-sided mark alignment system for aligning a first side and a second side of a lithography object 4, the double-sided mark alignment system including a collimated light source 31, amicroscope system 32, astage 33, and acontrol system 34, and further includes, in order to perform double-sided exposure alignment of the super-surface lithography system: and amarking unit 5 for performing alignment marking on the lithography object 4.

Wherein theworktable 33 is used for realizing the movement and/or rotation of the lithography object 4, and the precision of theworktable 33 is hundreds of nanometers to micron-scale precision.Control system 34 is used to controlstage 33 andmicroscopy system 32.

The light source 1 and the exposure projection system 2 are configured to: in the case of aligning the lithography object 4 by means of a double-sided mark alignment system, the lithography object 4 is subjected to first-side and second-side exposures, respectively.

Illustratively, the lithographic object 4 includes a planar lithographic object or a non-planar lithographic object. For example, a planar lithographic object includes a wafer or a planar substrate; non-planar lithographic objects include stepped or curved substrates, such as freeform or discretely curved substrates.

Illustratively, the collimated light source 31 includes a light source (e.g., a near infrared light LED) and a collimating lens. The light source and the collimating lens may be integrated into one device. The wavelength of the radiation generated by the light source (i.e. collimated light) has an extinction coefficient of less than 0.01 for the lithographic object 4 (e.g. a glass wafer) and a divergence angle of less than 10 ° after collimation. Optionally, the radiation generated by the light source comprises near infrared, mid infrared, far infrared, laser, and visible light. Preferably, the near-infrared light generated by the light source includes incoherent light having wavelengths of 850nm, 940nm, 1310nm and 1550nm, and the divergence angle of the near-infrared light generated by the light source after collimation is less than 10 °.

Specifically, as shown in fig. 1, an embodiment of a lithography system for super surface processing provided by the embodiments of the present application is as follows:

the system comprises a light source 1, an exposure projection system 2 and a double-sided mark alignment system for aligning a first side and a second side of a photoetching object 4, wherein the double-sided mark alignment system comprises a collimation light source 31, amicroscope system 32, aworkbench 33 and acontrol system 34, and in order to carry out double-sided exposure alignment of the super-surface photoetching system, the photoetching system for super-surface processing further comprises: and amarking unit 5 for performing alignment marking on the lithography object 4.

Wherein theworktable 33 is used for realizing the movement and/or rotation of the lithography object 4, and the precision of theworktable 33 is hundreds of nanometers to micron-scale precision.

The light source 1 and the exposure projection system 2 are configured to: in the case of aligning the lithography object 4 by means of a double-sided mark alignment system, the lithography object 4 is subjected to first-side and second-side exposures, respectively.

The movement patterns of the light source 1 and the exposure projection system 2 illustratively include a step-by-step type, a scanning type, or a combination of the step-by-step type and the scanning type.

Illustratively, the light source 1 is disposed above the exposure projection system 2, and the double-sided mark alignment system is disposed below the exposure projection system 2. The lithographic object 4 is set on astage 33 of a double-sided mark alignment system. The optical axes of the collimating light source 31 and the microscope objective of themicroscope system 32 are arranged in a coincident and opposite manner. Themicroscope system 32 and thestage 33 are each connected to acontrol system 34.

In the exemplary embodiment of the present application, the relative positions of the light source 1, the exposure projection system 2, the collimated light source 31, and themicroscope system 32 are fixed. The object 4 is set on thestage 33, and the markingunit 5 is set on the surface of one side of the object 4 near the edge. Thestage 33 is controlled to move the lithographic object 4 between themicroscope system 32 and the collimated light source 31 so that the markingunit 5 is located in the field of view of the microscope objective of themicroscope system 32. The lithographic object 4 is moved and/or rotated by thestage 33 such that the markingunit 5 is located in the center of the field of view of the microscope objective of themicroscope system 32 and the markingunit 5 is perpendicular to the optical axis of the collimated light source 31. At this time, the markingunit 5 is photographed by themicroscope system 32 and recorded as an initial picture, and the central point of the initial picture is recorded as the origin of coordinates (0, 0, 0). The first surface exposure is performed by moving the lithography object 4 below the exposure projection system 2.

Exemplarily, the focus position of the exposure projection system 2 is determined as a first coordinate and the center point of the area to be exposed of the lithographic object 4 is determined as a second coordinate. And calculating a vector which is required to move the center point of the area to be exposed to the first coordinate for photoetching to be a first vector according to the first coordinate and the second coordinate.

After the first side of the object 4 is exposed, the second side of the object 4 is set on thestage 33. The lithographic object 4 is moved such that the markingunit 5 is located in the field of view of the microscope objective of themicroscope system 32. The alignment is ended when the imaging of the markingunit 5 in themicroscope system 32 coincides with the markingunit 5 in the initial picture by moving or rotating the lithography object 4 by thestage 33. The height of the object 4 is lowered by thestage 33, the moving distance is the thickness of the object 4, and the center of the secondsurface marking unit 5 is recorded as the origin of coordinates (0, 0, 0).

Illustratively, the lithographic object 4 is first moved down by the thickness of the lithographic object 4. And then the photoetching object 4 is moved to the position corresponding to the first surface structure below the exposure projection system 2, namely the position of the first coordinate for carrying out second surface exposure. At this time, the motion vector is equal to the first vector.

Exemplarily, when the lithography object 4 is a non-planar surface, the second coordinate is a coordinate of a center of an equivalent plane of the area to be exposed, and the first vector further includes a rotation vector. The lithography object 4 is rotated according to the rotation vector such that the normal of the equivalent plane of the area to be exposed coincides with the optical axis of the exposure projection system 2. Since the write field of the exposure projection system 2 is only a few microns, the non-planar curvature variation over the write field is negligible and can be equated to a planar surface. The equivalent method is as follows:

determining the center point (x) of the area to be exposed₁,y₁,z₁) The normal vector of the center point is (k)_x,k_y,k_z) Then the equation of the equivalent plane is k_x(x-x₁)+k_y(y-y₁)+k_z(z-z₁)＝0。

It should be understood that in the present embodiment, the positions of the light source 1, the exposure projection system 2, and the double-sided mark alignment system are not limited to being placed one above the other. As long as the light source 1 is capable of projecting an image or structure onto the lithographic object 4 by means of the exposure projection system 2.

It should be understood that, as shown in fig. 2 to 5, in the embodiment of the present application, the markingunit 5 optionally includes acoarse alignment mark 51 and afine alignment mark 52. The alignment is completed when the imaging of the markingunit 5 in themicroscope system 32 coincides with both thecoarse alignment mark 51 and thefine alignment mark 52 of the markingunit 5 in the initial picture. The markingunit 5 is made of a material opaque to collimated light emitted from the collimated light source 31. Preferably, the material of the markingunit 5 is a near infrared opaque material. The shape of the markingunit 5 includes one or more of a cross shape, a comb shape, a rectangular shape, a circular shape, and a ring shape.

Illustratively, the shapes of the coarse alignment marks 51 and the fine alignment marks 52 include one or more of a cross shape, a comb shape, a rectangular shape, a circular shape, and a ring shape. Fig. 2 to 5 show the alignment and misalignment of the markingunit 5 in the imaging and initial pictures of the markingunit 5 in themicroscope system 32.

As shown in fig. 1, in the present embodiment, the table 33 optionally includes aposture adjustment device 331 and acarrier 332, and thecarrier 332 is detachably connected to theposture adjustment device 331. Thecarrier 332 is used for fixing the lithography object 4, and thepose adjusting device 331 is used for adjusting the position and/or pose of thecarrier 332, so that the position and/or pose of the lithography object 4 is adjusted. The maximum displacement stroke of thepose adjusting device 331 is larger than the size of the lithographic object 4, the rotation stroke of thepose adjusting device 331 is 360 °, and the minimum rotation angle of thepose adjusting device 331 is less than or equal to 0.1 °. The minimum rotation angle of theposture adjustment device 331 means the minimum angle at which theposture adjustment device 331 can rotate.

It should be noted that the pose adjustment refers to adjusting the position and/or the posture. The position adjustment includes movement along at least one of an X-axis, a Y-axis, and a Z-axis; the attitude adjustment includes rotation about at least one of an X-axis, a Y-axis, and a Z-axis. The Z axis is perpendicular to the horizontal plane, and the X axis and the Y axis are perpendicular to the Z axis respectively. It should be understood that thecarriers 332 are used to hold the lithography object 4, and thecorresponding carrier 332 may be selected according to the shape of the lithography object 4. For example, when the lithography object 4 is a wafer, thecarrier 332 is an object stage; when the lithographic object 4 is a non-planar substrate, thecarrier 332 is a gripper.

Exemplarily, as shown in fig. 2, the imaging of the markingunit 5 in themicroscope system 32 coincides completely with the markingunit 5 in the initial picture, and the second side of the lithographic object 4 is aligned. As shown in fig. 3, the imaging of the markingunit 5 in themicroscope system 32 is misaligned with the markingunit 5 in the initial picture in the X-axis direction, and the position of thecarrier 332 needs to be adjusted in the X-axis direction by thepose adjusting device 331 so that the imaging of the markingunit 5 in themicroscope system 32 completely coincides with the markingunit 5 in the initial picture, as shown in fig. 2.

As shown in fig. 4, the imaging of the markingunit 5 in themicroscope system 32 is misaligned with the markingunit 5 in the initial picture in the Y-axis direction, and the position of thecarrier 332 needs to be adjusted in the Y-axis direction by thepose adjustment device 331 so that the imaging of the markingunit 5 in themicroscope system 32 completely coincides with the markingunit 5 in the initial picture, as shown in fig. 2.

As shown in fig. 5, the imaging of the markingunit 5 in themicroscope system 32 is misaligned with the angle of rotation of the markingunit 5 in the initial picture around the Z-axis, and the posture of thecarrier 332 needs to be adjusted by rotating theposture adjustment device 331 around the Z-axis direction, so that the imaging of the markingunit 5 in themicroscope system 32 and the markingunit 5 in the initial picture completely coincide with each other as shown in fig. 2.

In the embodiment of the present application, preferably, thecoarse alignment mark 51 is used to complete the alignment along the X, Y axis direction, and then thefine alignment mark 52 is used to determine the angular alignment of the imaging of the markingunit 5 in themicroscope system 32 with the rotation of the markingunit 5 around the Z axis in the initial picture.

Preferably, theposture adjustment device 331 includes an X-axislinear displacement platform 3311, a Y-axislinear displacement platform 3312, a Z-axislinear displacement platform 3313, and arotation platform 3314.

Illustratively, as shown in fig. 1, the system includes a light source 1, an exposure projection system 2, and a double-sided mark alignment system for aligning a first side and a second side of a lithography object 4, the double-sided mark alignment system including a collimated light source 31, amicroscope system 32, astage 33, and acontrol system 34, and further includes, in order to perform double-sided exposure alignment of the super-surface lithography system: and amarking unit 5 for performing alignment marking on the lithography object 4.

The table 33 includes apose adjusting device 331 and acarrier 332. Theposture adjusting device 331 includes an X-axislinear displacement stage 3311, a Y-axislinear displacement stage 3312, a Z-axislinear displacement stage 3313, and arotation stage 3314. Wherein the Z-axislinear displacement platform 3313 is vertically fixed to the horizontal plane; the Y-axislinear displacement stage 3312 is connected to the displacement member of the Z-axislinear displacement stage 3313, and the Y-axislinear displacement stage 3312 is perpendicular to the Z-axislinear displacement stage 3313; the X-axislinear displacement stage 3311 is connected to the displacement member of the Y-axislinear displacement stage 3312, and the X-axislinear displacement stage 3311 is perpendicular to the Y-axislinear displacement stage 3312 and the Z-axislinear displacement stage 3313, respectively. Therotary platform 3314 is connected to the displacement member of the X-axislinear displacement platform 3311; the turret table 3314 rotates at least about the Z-axis.

The collimated light source 31 and themicroscope system 32 are mounted opposite to each other with the optical axis parallel to the Z-axis. The light source 1 and the exposure projection system 2 are configured to: in the case of aligning the lithography object 4 by means of a double-sided mark alignment system, the lithography object 4 is subjected to first-side and second-side exposures, respectively.

Taking the lithography object 4 as an example of a wafer, the implementation manner of the lithography system for super surface processing provided by the embodiment of the present application is as follows:

the wafer is set on thestage 33, and the markingunit 5 is set at the edge position of the wafer.Stage 33 is controlled to move the wafer betweenmicroscope system 32 and collimated light source 31 so that markingunit 5 is positioned in the field of view of the microscope objective ofmicroscope system 32. The wafer is moved and rotated by thestage 33 such that the markingunit 5 is positioned at the center of the field of view of the microscope objective of themicroscope system 32 and the markingunit 5 is perpendicular to the optical axis of the collimated light source 31. At this time, the markingunit 5 is photographed by themicroscope system 32 and recorded as an initial picture, and the center point of the picture is recorded as the origin of coordinates (0, 0, 0). The wafer is moved to a position below the exposure projection system 2 to perform the first surface exposure. The focus position of the exposure projection system 2 is determined as a first coordinate and the center point of the area to be exposed of the lithographic object 4 is determined as a second coordinate. And calculating a vector which is required to move the center point of the area to be exposed to the first coordinate for photoetching to be a first vector according to the first coordinate and the second coordinate.

After the first side of the object 4 is exposed, the second side of the wafer is set on thestage 33. The wafer is moved so that the markingunit 5 is located in the field of view of the microscope objective of themicroscope system 32. The alignment is ended when the imaging of the markingunit 5 in themicroscope system 32 coincides with the markingunit 5 in the initial picture by moving or rotating the wafer by thestage 33. The height of the wafer is lowered by thestage 33, the moving distance is the height of the wafer, and the center of the secondsurface marking unit 5 is recorded as the origin of coordinates (0, 0, 0). And moving the wafer to a position corresponding to the first surface structure below the exposure projection system 2 to perform second surface exposure.

The maximum displacement stroke of the X-axislinear displacement stage 3311, the Y-axislinear displacement stage 3312, and the Z-axislinear displacement stage 3313 is larger than the wafer diameter. The rotational travel of the rotating platform 334 is 360 ° and the minimum rotational angle is not greater than 0.1 °. Illustratively, when the lithographic object 4 is a 6 "wafer, the maximum displacement travel of the X-axislinear displacement stage 3311, the Y-axislinear displacement stage 3312, and the Z-axislinear displacement stage 3313 is greater than 150 mm.

Similarly, when the lithographic object 4 is a non-planar substrate, the first side alignment and the second side alignment of the lithographic object 4 are the same as the alignment embodiments when the lithographic object 4 is a wafer.

Taking the lithography object 4 as a free-form surface substrate as an example, the implementation manner of the lithography system for super surface processing provided by the embodiment of the present application is as follows:

taking a free-form surface substrate as an example, the implementation manner of the lithography system for super surface processing provided in the embodiments of the present application is as follows: the free-form surface substrate is set on the table 33 with the first surface thereof facing upward, and the markingunit 5 is set at the edge position of the first surface of the free-form surface substrate. The controlposture adjusting device 331 moves the free-form surface substrate between themicroscope system 32 and the collimated light source 31 so that themarker unit 5 is positioned in the field of view of the microscope objective lens of themicroscope system 32. The free-form surface substrate is moved and/or rotated by thepose adjustment device 331 so that themarker unit 5 is positioned at the center of the field of view of the microscope objective lens of themicroscope system 32 and themarker unit 5 is perpendicular to the optical axis of the collimated light source 31. At this time, the markingunit 5 is photographed by themicroscope system 32 and recorded as an initial picture, and the center point of the picture is recorded as the origin of coordinates (0, 0, 0). The first surface exposure is performed by moving the freeform substrate under the exposure projection system 2. When the first surface is exposed, thepose adjusting device 331 makes the equivalent plane of the area to be exposed of the free-form surface substrate on thecarrier 332 perpendicular to the optical axis of the exposure projection system 2 until the first surface is exposed.

After the first-side exposure of the object 4 is completed, the free-form surface substrate is set on thestage 33 with the second side facing upward. The free-form surface substrate is moved so that the markingunit 5 is located in the field of view of the microscope objective of themicroscope system 32. The alignment is ended when the imaging of the markingunit 5 in themicroscope system 32 coincides with the markingunit 5 in the initial picture by moving or rotating the wafer by thestage 33. The height of the free-form surface substrate is lowered by the table 33, the thickness of the free-form surface substrate is moved by the distance of the coordinate position, and the center of the secondsurface marking unit 5 is recorded as the origin of coordinates (0, 0, 0). And moving the free-form surface substrate to a position below the exposure projection system 2 corresponding to the first surface structure to perform second surface exposure. When the second surface is exposed, the equivalent plane of the area to be exposed of the free-form surface substrate on thecarrier 332 is kept perpendicular to the optical axis of the exposure projection system 2 through pose adjustment until the second surface is exposed.

The maximum displacement stroke of the X-axislinear displacement stage 3311, the Y-axislinear displacement stage 3312, and the Z-axislinear displacement stage 3313 is larger than the wafer diameter. The rotational travel of the rotating platform 334 is 360 ° and the minimum rotational angle is not greater than 0.1 °. Illustratively, when the lithographic object 4 is a 6 "wafer, the maximum displacement travel of the X-axislinear displacement stage 3311, the Y-axislinear displacement stage 3312, and the Z-axislinear displacement stage 3313 is greater than 150 mm.

It is to be understood that theposture adjustment device 331 is not limited to the combination of the linear displacement platform and the rotary platform.

In an alternative embodiment, themicroscope system 32 provided in the present embodiment includes amicroscope objective 321, a connectingtube 322, and animaging detector 323. Themicroscope 321 is a microscope, and themicroscope 321 and theimaging detector 323 are respectively located at two ends of the connectingpipe 322. The length of the connectingtube 322 is the back intercept of themicroscope objective 321, and the connectingtube 322 is also used to shield the ambient light to improve the signal-to-noise ratio. Illustratively, as shown in FIG. 1, a cantilevered mounting structure is provided on connectingtube 322 to support theentire microscope system 32.

Preferably, the operating band of theimaging detector 323 is an infrared band, and the total number of pixels is more than 30 ten thousand. In the embodiment of the present application, theimaging detector 323 may be a Complementary Metal Oxide Semiconductor (CMOS) or a Charge Coupled Device (CCD). Illustratively, themicroscope objective 321 has a magnification of 60x and a numerical aperture of 0.75. It should be understood that in the embodiment of the present application, the transmittance of the collimated light emitted from the collimated light source 31 by themicroscope objective 321 is high, for example, the transmittance of themicroscope objective 321 to near infrared light is greater than 80%.

Illustratively, as shown in fig. 1, an embodiment of the lithography system for super-surface processing provided by the embodiments of the present application is as follows:

the photoetching system comprises a light source 1, an exposure projection system 2 and a double-sided mark alignment system for aligning a first side and a second side of a photoetching object 4, wherein the double-sided mark alignment system comprises a collimation light source 31, amicroscope system 32, aworkbench 33 and acontrol system 34, and in order to carry out double-sided exposure alignment of the photoetching system with a super surface, the photoetching system for super surface processing further comprises: and amarking unit 5 for performing alignment marking on the lithography object 4.

Wherein theworktable 33 is used for realizing the movement and rotation of the lithography object 4, and the precision of theworktable 33 is hundreds of nanometers to micron-scale precision.

The light source 1 and the exposure projection system 2 are configured to: in the case of aligning the lithography object 4 by means of a double-sided mark alignment system, the lithography object 4 is subjected to first-side and second-side exposures, respectively.

The table 33 includes aposture adjustment device 331 and acarrier 332, and thecarrier 332 is detachably connected to theposture adjustment device 331. Thecarrier 332 is used for fixing the lithography object 4, and thepose adjusting device 331 is used for adjusting the position and/or pose of thecarrier 332, so that the position and/or pose of the lithography object 4 is adjusted. The maximum displacement stroke of thepose adjusting device 331 is larger than the size of the lithographic object 4, the rotation stroke of thepose adjusting device 331 is 360 °, and the minimum rotation angle of thepose adjusting device 331 is less than or equal to 0.1 °. The minimum rotation angle of theposture adjustment device 331 means the minimum angle at which theposture adjustment device 331 can rotate.

Theposture adjusting device 331 includes an X-axislinear displacement stage 3311, a Y-axislinear displacement stage 3312, a Z-axislinear displacement stage 3313, and arotation stage 3314. Wherein the Z-axislinear displacement platform 3313 is vertically fixed to the horizontal plane; the Y-axislinear displacement stage 3312 is connected to the displacement member of the Z-axislinear displacement stage 3313, and the Y-axislinear displacement stage 3312 is perpendicular to the Z-axislinear displacement stage 3313; the X-axislinear displacement stage 3311 is connected to the displacement member of the Y-axislinear displacement stage 3312, and the X-axislinear displacement stage 3311 is perpendicular to the Y-axislinear displacement stage 3312 and the Z-axislinear displacement stage 3313, respectively. The rotary platform 334 is connected to the displacement member of the X-axislinear displacement platform 3311.

The collimated light source 31 and themicroscope system 32 are mounted opposite to each other with the optical axis parallel to the Z-axis. The radiation emitted by the collimated light source 31 is incoherent near-infrared light with a wavelength of 940nm, and the divergence angle of the collimated near-infrared light is smaller than 10 degrees.

Microscope system 32 includesmicroscope objective 321, connectingtube 322, andimaging detector 323. Themicroscope 321 is a microscope, and themicroscope 321 and theimaging detector 323 are respectively located at two ends of the connectingpipe 322. The length of the connectingtube 322 is the back intercept of themicroscope objective 321, and the connectingtube 322 is also used to shield the ambient light to improve the signal-to-noise ratio.

Illustratively, the light source 1 is disposed above the exposure projection system 2, and the double-sided mark alignment system is disposed below the exposure projection system 2. The lithographic object 4 is set on astage 33 of a double-sided mark alignment system. The optical axes of the collimating light source 31 and the microscope objective of themicroscope system 32 are arranged in a coincident and opposite manner. Themicroscope system 32 and thestage 33 are each connected to acontrol system 34.

The object 4 is set on acarrier 332, and the markingunit 5 is set at an edge position of the object 4. Thecarrier 332 is controlled by thepose adjusting device 331 to move the lithography object 4 between themicroscope objective 321 and the collimated light source 31, so that the markingunit 5 is positioned in the field of view of themicroscope objective 321. The lithographic object 4 is moved and rotated by thestage 33 such that the markingunit 5 is located in the center of the field of view of the microscope objective of themicroscope system 32 and the markingunit 5 is perpendicular to the optical axis of the collimated light source 31. At this time, the markingunit 5 is photographed by themicroscope system 32 and recorded as an initial picture, and the center point of the picture is recorded as the origin of coordinates (0, 0, 0). The first surface exposure is performed by moving the lithography object 4 below the exposure projection system 2.

After the first side of the object 4 is exposed, the second side of the object 4 is set on thecarrier 332. The lithographic object 4 is moved such that the markingunit 5 is located in the field of view of the microscope objective of themicroscope system 32. The lithography object 4 is moved or rotated by theposture adjusting device 331 so that the imagedcoarse alignment mark 51 andfine alignment mark 52 of the markingunit 5 in themicroscope system 32 coincide with thecoarse alignment mark 51 andfine alignment mark 52 of the markingunit 5 in the initial picture, respectively, and the alignment is ended. The height of the lithography object 4 is lowered by thecarrier 332, the moving distance is the height of the lithography object 4, and the center of the secondsurface marking unit 5 is recorded as the origin of coordinates (0, 0, 0). And moving the photoetching object 4 to a corresponding exposure position below the exposure projection system 2 to perform second-side exposure.

In summary, in the lithography system for super-surface processing according to the embodiment of the present application, the marking unit on the first surface of the lithography object is imaged by the collimated light source, so that the marking unit is located at the center of the field of view of the microscope system and photographed as an initial picture; the alignment of the second surface of the photoetching object is realized by aligning the marking unit with the marking unit in the initial picture when the second surface of the photoetching object is placed. The alignment of a coarse alignment mark and a fine alignment mark under the imaging of a collimated light wave band enables a workbench with the precision of hundreds of nanometers to micron to realize the photoetching processing of the super surface through medium-precision movement; the cost of super-surface machining is reduced by replacing the ultra-high precision table with the medium precision table. The lithography system also enables the processing of the super-surface of a non-planar substrate by movement and/or rotation of the stage during exposure.

The embodiment of the application also provides a photoetching method for super surface processing, and as shown in FIG. 6, the method at least comprises the following steps.

In step S1, a markingunit 5 is disposed on the edge of the first surface of the lithography object 4. The object 4 is placed on astage 33, and amarking unit 5 is provided on an edge of a first face of the object 4.

And step S2, positioning the first surface and taking a picture to record as an initial picture. The lithography object 4 is moved and/or rotated such that the markingunit 5 is located at the center of the field of view of the microscope objective of themicroscope system 32, themicroscope system 32 takes a picture of the markingunit 5 and records it as an initial picture, and the coordinates of the center point of the initial picture are recorded as the origin of coordinates (0, 0, 0).

Exemplarily, if an XYZ coordinate system is established with the center of the initial picture as the origin and the direction perpendicular to the horizontal plane as the Z axis, the movement and rotation of the lithography object 4 satisfy:

where k is a normal vector of the equivalent plane of the lithography object 4, and θ is a rotation vector of the lithography object 4.

In step S3, the first surface is exposed. The lithography object 4 is exposed to the exposure position of the exposure projection system 2, and the exposure of the first side of the lithography object 4 is completed.

In step S4, after the exposure of the first surface is completed, the second surface of the lithographic object 4 is aligned using the initial picture. The lithographic object 4 with the first side exposed is placed upside down on the table 33 and the lithographic object 4 is moved and/or rotated such that the imaging of the markingunit 5 in themicroscope system 32 coincides with the markingunit 5 in the initial picture. Illustratively, the markingunit 5 includes acoarse alignment mark 51 and afine alignment mark 52. The second side completes the alignment when the imagedcoarse alignment mark 51 andfine alignment mark 52 of the markingunit 5 in themicroscope system 32 coincide with thecoarse alignment mark 51 andfine alignment mark 52, respectively, in the original picture.

In step S5, the second surface is exposed. The height of the lithography object 4 is reduced, which is the height of the lithography object 4. The second-side exposure is completed by moving the lithography object 4 to the exposure position of the exposure projection system 2.

Illustratively, the embodiments of the lithography method for super-surface processing provided by the embodiments of the present application are as follows:

the object 4 is set on thestage 33 with the first surface facing upward, and the markingunit 5 is set at the edge position of the object 4. Thestage 33 is controlled to move the lithographic object 4 between themicroscope system 32 and the collimated light source 31 so that the markingunit 5 is located in the field of view of the microscope objective of themicroscope system 32. The lithographic object 4 is moved and/or rotated by the stage 3 such that the markingunit 5 is located in the center of the field of view of the microscope objective of themicroscope system 32 and the markingunit 5 is perpendicular to the optical axis of the collimated light source 31. At this time, the markingunit 5 is photographed by themicroscope system 32 and recorded as an initial picture, and the central point of the initial picture is recorded as the origin of coordinates (0, 0, 0). The first surface exposure is performed by moving the lithography object 4 below the exposure projection system 2. When the lithography object 4 is a non-planar substrate, the equivalent plane of the region to be exposed of the non-planar substrate is always perpendicular to the optical axis of the projection exposure system 2 during exposure.

After the first side of the object 4 is exposed, the second side of the object 4 is set on thestage 33. The lithographic object 4 is moved such that the markingunit 5 is located in the field of view of the microscope objective of themicroscope system 32. The alignment is ended when the imaging of the markingunit 5 in themicroscope system 32 coincides with the markingunit 5 in the initial picture by moving or rotating the lithography object 4 by thestage 33. The height of the object 4 is lowered by thestage 33, the moving distance is the height of the object 4, and the center of the secondsurface marking unit 5 is recorded as the origin of coordinates (0, 0, 0). And moving the photoetching object 4 to a position corresponding to the first surface structure below the exposure projection system 2 to perform second surface exposure.

According to the photoetching system and the method for super-surface processing, provided by the embodiment of the application, a marking unit positioned in the center of the visual field of a microscope system is photographed into an initial picture; the marking unit is overlapped with the marking unit in the initial picture when the second surface of the photoetching object is placed, so that the second surface of the photoetching object is aligned. The alignment of a coarse alignment mark and a fine alignment mark under the imaging of a collimated light wave band enables a workbench with the precision of hundreds of nanometers to micron to realize the photoetching processing of the super surface through medium-precision movement; the cost of super-surface machining is reduced by replacing the ultra-high precision table with the medium precision table.

The above description is only a specific implementation of the embodiments of the present application, but the scope of the embodiments of the present application is not limited thereto, and any person skilled in the art can easily conceive of changes or substitutions within the technical scope of the embodiments disclosed in the present application, and all the changes or substitutions should be covered by the scope of the embodiments of the present application. Therefore, the protection scope of the embodiments of the present application shall be subject to the protection scope of the claims.

Claims (10)

1. A lithography system for super-surface processing, comprising a light source (1), an exposure projection system (2), a double-sided marking alignment system and a marking unit (5) for making alignment marks for a lithographic object (4);

wherein the light source (1) is arranged above the exposure projection system (2) and the double-sided mark alignment system is arranged below the exposure projection system (2);

the double-sided mark alignment system comprises a collimated light source (31), a microscope system (32), a workbench (33) and a control system (34);

the workbench (33) comprises a pose adjusting device (331) and a carrier (332); the carrier (332) is detachably connected with the pose adjusting device (331); the pose adjusting device (331) is used for adjusting the position and/or the posture of the carrier (332); the precision of the working table (33) is hundreds of nanometers to micron-scale precision.

2. The lithography system for super-surface processing according to claim 1, wherein the attitude adjusting device (331) includes an X-axis linear displacement stage (3311), a Y-axis linear displacement stage (3312), a Z-axis linear displacement stage (3313), and a rotation stage (3314);

wherein the Z-axis linear displacement platform (3313) is vertically and fixedly mounted with a horizontal plane;

the Y-axis linear displacement platform (3312) is connected to a displacement member of the Z-axis linear displacement platform (3313), and the Y-axis linear displacement platform (3312) is perpendicular to the Z-axis linear displacement platform (3313);

the X-axis linear displacement platform (3311) is connected to a displacement member of the Y-axis linear displacement platform (3312), and the X-axis linear displacement platform (3311) is perpendicular to the Y-axis linear displacement platform (3312) and the Z-axis linear displacement platform (3313), respectively;

the rotating platform (3314) is connected with a displacement piece of the X-axis linear displacement platform (3311);

the rotating platform (3314) rotates at least about the Z axis;

the Z axis is perpendicular to the horizontal plane, and the X axis and the Y axis are perpendicular to the Z axis respectively.

3. Lithography system for super-surface processing according to claim 1 or 2, wherein the maximum displacement travel of the pose adjustment means (331) is larger than the size of the lithographic object (4).

4. The lithography system for super-surface processing according to claim 1 or 2, wherein the rotational stroke of the attitude adjusting device (331) is 360 °.

5. The lithography system for super-surface processing according to claim 1 or 2, wherein the minimum rotation angle of the attitude adjustment device (331) is less than or equal to 0.1 °.

6. Lithography system for superfinishing according to claim 1, wherein the lithography object (4) comprises a planar lithography object or a non-planar lithography object.

7. Lithography system for super-surface processing according to claim 1 or 6, wherein the marking unit (5) is located close to an edge on a side surface of the lithography object (4).

8. Lithography system for super-surfacing according to claim 7, wherein the marking unit (5) is made of a material that is opaque to near-infrared light.

9. Lithography system for super-surface machining according to claim 8, wherein said marking unit (5) comprises a coarse alignment mark (51) and a fine alignment mark (52).

10. The lithography system for super-surface processing as claimed in claim 9, wherein the shape of said marking unit (5) comprises one or more of a cross, a comb, a rectangle, a circle and a ring.

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