Lamp optical system and the lithographic equipment for using the lamp optical systemTechnical field
The present invention relates to a kind of lamp optical system, especially a kind of lamp optical system of multi-wavelength LED array of source,It is mainly used in microlithography technology, applies also for other to brightness of illumination and the higher optical system of visual field uniformity requirement.Further relate to a kind of lithographic equipment using the lamp optical system.
Background technique
Microlithography technology in semiconductors manufacture is exactly that the figure on mask plate is accurately projected exposure using optical systemOn light to the silicon wafer of coated photoresist.
There are mainly two types of the light sources that existing lamp optical system uses, and one is mercury lamp light source, another kind is LED lightSource.
However, system assembling and setting is whole it has been found that existing mercury lamp light source lamp optical system is designed in systemIt is had the following disadvantages: in machine use process
1, in design process, the lamp house design comparison of mercury lamp light source is complicated；
2, in system equipment debugging process, mercury lamp light source lamp house is by lamp house mechanical device, ellipsoidal reflector, plane mirrorAnd mercury lamp composition, component is more, causes the freedom degree in debugging process more, during system is equipped and debugged, should not adjustIt tries to optimum position, debugging process is complicated, and debugging cycle is longer；
3, mercury lamp light source has certain risk.High-pressure mercury vapor is full of in mercury lamp light source light bulb, if improper use is sent outRaw leakage has very big harm to environment and staff；
4, existing mercury lamp light source lighting system due to component it is more, optical energy loss is serious in entire optical path, effective wave bandThe efficiency of light energy utilization is low.
With the development of LED light source technology, it is high-power high-strength that the power of LED light source becomes closer to modern semiconductors industryThe demand of degree, LED light source have very big application prospect.LED light source generally comprises substrate, and LED lamp, LED are provided on substrateIt is potting resin outside wick.LED light source has the characteristics that small in size, the service life is long, outgoing optical power is easily controllable.In different usesUnder scene, LED light source carrys out meet demand by using different collection of energy and light balancing device.
Summary of the invention
The present invention in view of the above technical problems, proposes a kind of lamp optical system and the light using the lamp optical systemEquipment is carved, the lamp optical system structure is simple, and capacity usage ratio is high, is easily installed debugging and control, highly-safe.
Technical scheme is as follows:
A kind of lamp optical system, comprising:
The mutually different at least two groups LED light source array of peak wavelength；
It is arranged in each group LED light source array light emission side correspondingly respectively, so that every group of LED light source array issuedLight beam becomes several beam collimation elements of collimated light beam after its transmission；
Each beam collimated light beam for transmiting each beam collimation element synthesizes a whole total collimated light beam of beamSeveral beam combining elements；
Light beam coupling element in the optical path of total collimated light beam；
And
Positioned at the equal optical element of the light beam coupling element light emission side；
Total collimated light beam injects the equal optical element after the coupling of the light beam coupling element, described equalThe exit end of optical element obtains the collimated light beam that light is evenly distributed.
The present invention further includes following preferred embodiment based on the above technical solution:
The beam collimation element is collimation lens set.
The light beam coupling element is coupled lens group.
The equal optical element is quartz pushrod.
The beam combining element is prism.
The prism is right-angle prism.
The beam combining element is spectroscope.
The LED light source array shares three groups, respectively the first LED light source array, the second LED light source array and thirdLED light source array；There are three the collimation lens set is total, respectively the first collimation lens set, the second collimation lens set and thirdCollimation lens set；The spectroscope shares two pieces, respectively the first spectroscope and the second spectroscope；Wherein:
First collimation lens is mounted on the light emission side of first LED light source array, and the first LED light source array issuesLight beam through obtaining the first collimated light beam after first collimation lens set；
Second collimation lens is mounted on the light emission side of second LED light source array, and the second LED light source array issuesLight beam through obtaining the second collimated light beam after second collimation lens set；
The third collimation lens is mounted on the light emission side of the third LED light source array, and third LED light source array issuesLight beam through obtaining third collimated light beam after the third collimation lens set；
First spectroscope is located at the optical path of first collimated light beam and the light of second collimated light beam simultaneouslyOn the road, which transmits first collimated light beam and reflects second collimated light beam, and the second collimated light beamReflection direction it is identical as the transmission direction of the first collimated light beam, so that the first collimated light beam and the second collimated light beam be synthesizedSecond spectroscopical 4th collimated light beam described in directive；
Second spectroscope is located at the optical path of the third collimated light beam and the light of the 4th collimated light beam simultaneouslyOn the road, second spectroscope transmission is described reflects the third collimated light beam at the 4th collimated light beam, and third directional lightThe reflection direction of beam is identical as the transmission direction of the first collimated light beam, so that third collimated light beam and the 4th collimated light beam be synthesizedFor total collimated light beam of coupled lens group described in directive；
Total collimated light beam becomes convergent beam after the coupling of coupled lens group, which injects the stoneEnglish stick, through the even light of multiple reflections in the quartz pushrod, the exit end of the quartz pushrod obtain light be evenly distributed it is parallelLight beam.
First LED light source array, the first collimation lens set, the first spectroscope, the second spectroscope, coupled lens group andQuartz pushrod is arranged on same straight line, and is successively arranged along the straight line.
LED light source array described in each group is arranged by the identical several LED light sources of peak wavelength, and each groupThe LED light source array is centrosymmetric structure, and the straight line is the symmetrical center line of first LED light source array.
The peak wavelength of each LED light source is 435nm, 405nm or 365nm in the LED light source array.
First spectroscope and the second spectroscope be mutually perpendicular to arrange, first spectroscope and second directional lightThe angle of beam, first spectroscope and the angle of the third collimated light beam, second spectroscope are parallel with the described 4thThe angle of the angle of light beam and second spectroscope and total collimated light beam is 45 °；Second LED light source arrayThe light beam that light beam is issued with the first LED light source array is issued to be mutually perpendicular to；Light beam that the third LED light source array issues and theThe light beam that one LED light source array issues is mutually perpendicular to, and parallel with the light beam that the second LED light source array issues.
The collimation lens set includes the first lens, the second lens and the third lens successively arranged along optical axis, wherein theThe object plane of one lens is located at the light end out of LED light source array.
In each collimation lens set, light hole of first lens towards the LED light source array sideDiameter is greater than the circumradius of the LED light source array.
The clear aperature of first lens towards the LED light source array side is the external of the LED light source array5~6 times of radius of circle.
The object-side numerical aperture of the collimation lens set is 0.7~0.8, and object plane bore is 2~11mm, and amplification factor is 5Times or more.
This lithographic equipment provided by the present invention, the lamp optical system including above structure.
The light beam that the present invention is emitted the LED light source array of different wave length, synthesize a branch of wide spectrum multi-peak wavelength,The collimated light beam that light is evenly distributed, coupled lens group are converted to convergent beam, into quartz pushrod, have the advantage that
1, relative to lighting system of the mercury lamp as light source is used, the present invention uses LED light source, and light path design is simply skilfulWonderful, capacity usage ratio is high, reduces optical energy loss, is easily installed debugging, highly-safe.
2, relative to single led array of source is used, the present invention uses the multiple groups LED light source array of different peak wavelengths,Luminous energy is high, and brightness is high, spectral width, and peak wavelength is more.
3, relative to the illumination scheme for using the even light collimation LED array transmitting light beam of microlens array in traditional technology, originallyInvention uses collimation lens set, and structure is simpler, and cost is cheaper.
Detailed description of the invention
The invention will be described further in the following with reference to the drawings and specific embodiments:
Fig. 1 is the structural schematic diagram of lamp optical system in the embodiment of the present invention, and in the Fig. 1, α is that the first collimated light beam existsIncidence angle on first spectroscope, β are angle of second collimated light beam on the first spectroscope, and γ is third collimated light beam theAngle on two spectroscopes；
Fig. 2 is the structural schematic diagram of collimation lens set in lamp optical system in the embodiment of the present invention；
Fig. 3 is the spatial distribution schematic diagram of total collimated light beam in the embodiment of the present invention；
Wherein: the first LED light source array of 101-, the first collimation lens set of 102-, the first spectroscope of 103-, 104- secondLED light source array, the second collimation lens set of 105-, 106- third LED light source array, 107- third collimation lens set, 108-Two spectroscopes, 109- coupled lens group, 110- quartz pushrod；
The first lens of 201-, the second lens of 202-, 203- the third lens.
Specific embodiment
This lamp optical system of the present invention, comprising:
The mutually different at least two groups LED light source array of peak wavelength；
It is arranged in each group LED light source array light emission side correspondingly respectively, so that every group of LED light source array issuedLight beam becomes several beam collimation elements of collimated light beam after its transmission；
Each beam collimated light beam for transmiting each beam collimation element synthesizes a whole total collimated light beam of beamSeveral beam combining elements；
Light beam coupling element in the optical path of total collimated light beam；
And
Positioned at the equal optical element of the light beam coupling element light emission side；
Total collimated light beam injects the equal optical element after the coupling of the light beam coupling element, described equalThe exit end of optical element obtains the collimated light beam that light is evenly distributed.
Fig. 1 shows a specific embodiment of this multi-wavelength LED array of source lighting system of the present invention, the system packetIt includes:
Three groups of LED light source arrays, the first LED light source array 101 of difference, the second LED light source array 104 and third LED lightSource array 106；
Three collimation lens sets (for beam collimation element described in the present invention), respectively the first collimation lens set 102,Two collimation lens sets 105 and third collimation lens set 107；
Two pieces of spectroscopes (for beam combining element described in the present invention), respectively the first spectroscope 103 and third light splittingMirror 108；
Coupled lens group 109 (for light beam coupling element described in the present invention)；
Quartz pushrod 110 (for equal optical element described in the present invention).Wherein:
This three groups of LED lights of first LED light source array 101, the second LED light source array 104 and third LED light source array 106The peak wavelength of source array is different, and every group of LED light source array is by several LED light sources of same model according to certain sideFormula is arranged in a combination, and each group of LED light source array is centrosymmetric structure, i.e., every group of LED light source array all hasThe symmetrical center line of oneself, at the angle of every group of LED light source array kind each LED light source, distribution is lambertian distribution.Why locateEach LED light source in same group of LED light source array selects same model, is the peak value wave in order to guarantee these LED light sourcesLength is identical.
First collimation lens set 102 is set to the light emission side of the first LED light source array 101, the first LED light source array 101 hairLight beam out obtains the first collimated light beam after the transmission of the first collimation lens set 102.
Second collimation lens set 105 is set to the light emission side of the second LED light source array 104, the second LED light source array 104 hairLight beam out obtains the second collimated light beam after the transmission of the second collimation lens set 105.
Third collimation lens set 107 is set to the light emission side of third LED light source array 106, and third LED light source array 106 is sent outLight beam out obtains third collimated light beam after the transmission of third collimation lens set 107.
The object plane of each collimation lens set is respectively positioned on the light end out of corresponding LED light source array.The effect of collimation lens setIt is that will to correspond to the beam collimation of LED light source array outgoing be directional light, and the angle of emergence is evenly distributed.
First spectroscope 103 had not only been located in the optical path of first collimated light beam, but also was located at second collimated light beamIn optical path.First spectroscope 103 transmits first collimated light beam and reflects second collimated light beam, and second is flatThe reflection direction of row light beam is identical as the transmission direction of the first collimated light beam, thus by the first collimated light beam and the second collimated light beamSynthesize the 4th collimated light beam of the second spectroscope 108 described in directive (two beam directional lights are synthesized into a branch of directional light).
Second spectroscope 108 had not only been located in the optical path of the third collimated light beam, but also was located at the 4th collimated light beamIn optical path.Second spectroscope 103 transmit it is described reflect the third collimated light beam at the 4th collimated light beam, and thirdThe reflection direction of collimated light beam is identical as the transmission direction of the first collimated light beam, thus by third collimated light beam and the 4th directional lightBeam synthesizes the 5th collimated light beam (two beam directional lights are synthesized a branch of directional light) of coupled lens group 109 described in directive, isIt helps reader to understand the solution of the present invention, the 5th collimated light beam is referred to as total collimated light beam herein.From the second spectroscope103 outgoing synthesis light beam, that is, total collimated light beam spatial distributions as shown in figure 3, it is not difficult to find out that, which isWide spectrum multi-peak wavelength light beam.
Coupled lens group 109 is set in the optical path of total collimated light beam.Quartz pushrod 110 is located at the coupled lens groupThe front end face of 109 light emission side, quartz pushrod is located in the image planes of coupled lens group.Total collimated light beam passes through coupled lens groupBecome convergent beam after 109 coupling, it is (i.e. described total parallel that coupled lens group changes resulting wide spectrum multi-peak wavelength light beamLight beam) NA, so that its is all injected the quartz pushrods 110, to improve capacity usage ratio.Light beam passes through in the quartz pushrod 110The even light of multiple reflections, in the directional light that the exit end of the quartz pushrod 110 obtains wide spectrum multi-peak wavelength, light is evenly distributedBeam (namely forming the Uniform Illumination visual field of certain visual field size in the exit end of quartz pushrod).
It refers again to shown in Fig. 1, in the present embodiment, first LED light source array 101, the first collimation lens set 102,One spectroscope 103, the second spectroscope 108, coupled lens group 109 and quartz pushrod 110 are arranged on same straight line, and along thisStraight line is successively arranged.This straight line is specially the symmetrical center line of first LED light source array 101.
Referring again to shown in Fig. 1, the second LED light source array 104 issues light beam and the sending of the first LED light source array 101Light beam is mutually perpendicular to, in other words, first collimated light beam being emitted from the first collimation lens set 102 with from the second collimation lensSecond collimated light beam of 105 outgoing of group is mutually perpendicular to.The light beam and the first LED that the third LED light source array 106 issuesThe light beam that array of source 101 issues is mutually perpendicular to, and parallel with the light beam that the second LED light source array 104 issues, in other words, fromThe 4th collimated light beam that third collimation lens set 107 is emitted be emitted from the first collimation lens set 102 it is described first flatRow light beam is parallel, and the 4th collimated light beam being emitted from third collimation lens set 107 goes out with from the second collimation lens set 105Second collimated light beam penetrated is mutually perpendicular to.
Referring again to shown in Fig. 1, first spectroscope 103 and the second spectroscope 108 are mutually perpendicular to arrange, and firstAngle formed by spectroscope 103 and incident beam, the reflected beams is 45 °, the second spectroscope 108 and incident beam, reflected lightAngle formed by beam is also 45 °.That is: angle=first spectroscope 103 of the first spectroscope 103 and second collimated light beamWith angle=45 ° of the third collimated light beam, angle=second light splitting of the second spectroscope 108 and the 4th collimated light beamAngle=45 ° of mirror 108 and total collimated light beam.
Referring to shown in Fig. 2, the collimation lens set includes the first lens 201, the second lens 202 and the third lens 203, andAnd first lens 201, the second lens 202 and the third lens 203 are successively arranged along optical axis, wherein the object plane of the first lens 201Positioned at the light end that goes out of corresponding LED light source array, (such as: the object plane of the first lens is located at the first LED light source in the first collimation lens setArray goes out light end), that is to say, that in this three pieces lens, for the first lens 201 near LED light source array, taking second place is secondThird lens 202 are the third lens 203.In each collimation lens set, in each collimation lens set, describedThe clear aperature (radius) of one lens towards the corresponding LED light source array side is greater than the circumradius of the LED light source array,90% or more divergent beams, which are assembled, in 110 ° of angular ranges that first lens 201 can issue the LED light source array entersCorresponding collimation lens set, the effect of the second lens 202 and the third lens 203 are further to collimate light beam.
Collimation lens set is not limited only to only be made of three pieces lens, can add more eyeglasses on this basis to optimizeCollimate performance.
The group number of the LED light source array is not limited to three groups of the present embodiment, is also possible to two groups, four groups or five groupsEtc..In other embodiments that those use remaining group number LED light source array, the collimation lens set and spectroscopicalNumber also needs accordingly to adjust.On the basis of disclosed in the present embodiment, skilled person will know how adjustment collimation is saturatingMicroscope group and spectroscopical number and position are come corresponding with the group number LED light source array of respective sets number, and details are not described herein.
Generally, the clear aperature of first lens towards the corresponding LED light source array side is the LED light source array5~6 times of circumradius.Preferably, the object-side numerical aperture of each collimation lens set (packet preferably in 0.7~0.8 rangeContaining 0.7,0.8), object plane bore is preferably 2~11mm (more preferably 10mm), and amplification factor is generally at 5 times or more.
The peak wavelength of each LED light source is preferably 435nm, 405nm, 365nm or more shortwave in single group LED light source arrayLong, specifically in the present embodiment, the peak wavelength of each LED light source is 435nm, the second LED light source in the first LED light source arrayThe peak wavelength of each LED light source is 405nm in array, and the peak wavelength of each LED light source is in third LED light source array365nm。
The present embodiment is using collimation lens set as beam collimation element, and spectroscope is as beam combining element, couplingLens group is closed as light beam coupling element, quartz pushrod is as equal optical element.It should be understood that the light beam of other forms can also be usedCollimating element, beam combining element, light beam coupling element and equal optical element implement the present invention, and peak wavelength is mutually differentThe light that multiple groups LED light source array issues collects utilization, obtains light and is evenly distributed and the higher collimated light beam of intensity.Such as technologyPersonnel can be using right-angle prism or other prisms substitution spectroscope as beam combining element.It is basic disclosed in the present embodimentOn skilled person will know how using other forms beam collimation element, beam combining element (such as right-angled edgeMirror or other prisms), light beam coupling element and equal optical element implement the present invention, details are not described herein.
This lighting system of the present embodiment is applicable not only to the optical system in microlithography technology, applies in litho machine,Other are applied also for brightness of illumination and the higher optical system of visual field uniformity requirement.
Certainly, the above embodiments merely illustrate the technical concept and features of the present invention, and its object is to make people much of thatThe solution contents of the present invention are simultaneously implemented accordingly, and it is not intended to limit the scope of the present invention.All major techniques according to the present inventionThe equivalent transformation or modification that the Spirit Essence of scheme is done, should be covered by the protection scope of the present invention.