Catadioptric optical system and exposure apparatus having the same

Abstract
A projection exposure lens system has an object side catadioptric system, and intermediate image and a refractive lens system. The refractive lens system from its intermediate image side and in the direction of its image plane has a first lens group of positive refractive power, a second lens group of negative refractive power, a third lens group of positive refractive power, a fourth lens group of negative refractive power, and a fifth lens group of positive refractive power.
Description


STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] Not applicable.



INCORPORATION BY REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

[0003] Not applicable.



BACKGROUND OF THE INVENTION


Field of the Invention

[0004] The present invention relates to a projection exposure lens in a projection exposure apparatus such as a wafer scanner or a wafer stepper used to manufacture semiconductor elements or other microstructure devices by photolithography and, more particularly, to a catadioptric projection optical lens with an object side catadioptric system, an intermediate image and a refractive lens system for use in such a projection exposure apparatus.



DESCRIPTION OF RELATED ART INCLUDING INFORMATION DISCLOSED UNDER 37 CFR 1.97 AND 1.98

[0005] U.S. Pat. No. 4,779,966 to Friedman gives an early example of such a lens, however the catadioptric system being arranged on the image side. Its development starting from the principle of a Schupmann achromat is described. It is an issue of this patent to avoid a second lens material, consequently all lenses are of fused silica. Light source is not specified, band width is limited to 1 nm.


[0006] U.S. Pat. No. 5,052,763 to Singh (EP 0 475 020) is another example. Here it is relevant that odd aberrations are substantially corrected separately by each subsystem, wherefore it is preferred that the catadioptric system is a 1:1 system and no lens is arranged between the object and the first deflecting mirror. A shell is placed between the first deflecting mirror and the concave mirror in a position more near to the deflecting mirror. All examples provide only fused silica lenses. NA is extended to 0.7 and a 248 nm excimer laser or others are proposed. Line narrowing of the laser is proposed as sufficient to avoid chromatic correction by use of different lens materials.


[0007] U.S. Pat. No. 5,691,802 to Takahashi is another example, where a first optical element group having positive refracting power between the first deflecting mirror and the concave mirror is requested. This is to reduce the diameter of the mirror, and therefore this positive lens is located near the first deflecting mirror. All examples show a great number of CaF2 lenses.


[0008] EP 0 736 789 A to Takahashi is an example, where it is requested that between the first deflecting mirror and the concave mirror three lens groups are arranged, with plus minus plus refractive power, also with the aim of reducing the diameter of the concave mirror. Therefore, the first positive lens is located rather near to the first reflecting mirror. Also many CaF2 lenses are used for achromatization.


[0009] DE 197 26 058 A to Omura describes a system where the catadioptric system has a reduction ratio of 0.75</β1/<0.95 and a certain relation for the geometry of this system is fulfilled as well. Also many CaF2 lenses are used for achromatization.


[0010] For purely refractive lenses of microlithography projection exposure system a lens design where the light beam is twice widened strongly is well know, see e.g. Glatzel, E., Zeiss-Information 26 (1981), No. 92 pages 8-13. A recent example of such a projection lens with +−+−+ lens groups is given in EP 0 770 895 to Matsuzawa and Suenaga.


[0011] The refractive partial objectives of the known catadioptric lenses of the generic type of the invention, however show much simpler constructions.


[0012] The contents of these documents are incorporated herein by reference. They give background and circumstances of the system according to the invention.


[0013] The contents of these documents are incorporated herein by reference. They given background and circumstances of the system according to the invention.



BRIEF SUMMARY OF THE INVENTION

[0014] It is an object of the present invention to obtain a catadioptric optical system of new construction principles allowing for large numerical aperture, large image field, sufficient laser bandwidth, solid and stable construction, which takes into account the present limitations on availability of CaF2 in quantity and quality. This holds for a DUV projection lens and gives the basis for a one material only lens for VUV (157 nm).


[0015] In order to achieve the above object, according to the present invention, there is provided a projection exposure lens according to one of claims 1 to 7 or any combination of them as claimed in claim 8.


[0016] Advantageous versions are obtained when including features of one or more of the dependent claims 8 to 28.


[0017] An advantageous projection exposure apparatus of claim 29 is obtained by incorporating a projection exposure lens according to at least one of claims 1 to 28 into a known apparatus.


[0018] A method of producing microstructured devices by lithography (claim 30) according to the invention is characterized by the use of a projection exposure apparatus according to the preceeding claim 29. Claim 31 gives an advantageous mode of this method.


[0019] The present invention will be more fully understood from the detailed description given hereinbelow and the accompanying drawings, which are given by way of illustration only and are not to be considered as limiting the present invention. Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will be apparent to those skilled in the art from this detailed description.







BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

[0020]
FIG. 1 is a view showing the arrangement of an exposure apparatus to which a catadioptric optical system according to the present invention can be applied;


[0021]
FIG. 2 is a section view of the lens arrangement of a first embodiment;


[0022]
FIG. 3 is a section view of the lens arrangement of a second embodiment;


[0023]
FIG. 4 is a section view of the lens arrangement of a third embodiment;


[0024]
FIG. 5 is a section view of the lens arrangement of a fourth embodiment;


[0025]
FIG. 6

a
is a section view of the lens arrangement of a fifth embodiment;


[0026]
FIG. 6

b
is a representation of an imaging error of the fifth embodiment;


[0027]
FIG. 7 is a schematic section view of part of the lens arrangement of a sixth embodiment.







DETAILED DESCRIPTION OF THE INVENTION

[0028] The projection exposure apparatus as schematically shown in FIG. 1 includes an excimer laser light source 1 with an arrangement 11 moderately narrowing bandwidth. An illumination system 2 produces a large field, sharply limited and illuminated very homogeneously, which matches the telecentricity requirements of the projection lens, and with an illumination mode to choice. Such mode may be conventional illumination of variable degree of coherence, annular or quadrupole illumination.


[0029] A mask 3 is displaced in the illuminated area by a mask holding and handling system 31, which includes the scanning drive in case of a wafer scanner projection exposure apparatus. Subsequently follows the catadioptric projection exposure lens 4, according to the invention to be described in detail subsequently.


[0030] This lens 4 produces a reduced scale image of the mask 3 on a wafer 5. The wafer 5 is held, handled and eventually scanned by unit 51.


[0031] All systems are controlled by control unit 6. Such unit and the method of its use is known in the art of microlithographic projection exposure.


[0032] However, for exposure of structures in the regime of about 0.2 μm and less resolution at high throughput there is a demand for various projection exposure lenses capable to be operated at 193 nm, eventually also at 248 nm or 157 nm excimer laser wavelengths with reasonably available bandwidths (e.g. 15 pm at 193 nm), at high image side numerical aperature of 0.65 to 0.8 or more with reasonably large rectangular or circular scanning image fields of e.g. 7×20 to 10×30 mm2.


[0033] Catadioptric systems of the type cited above are in principle suitable for this.


[0034] However, according to the invention a number of measures and features have been found to improve these systems.


[0035] The example shown in the sectional view of FIG. 2 has the lens data given in Table 1 and makes use only of fused silica lenses. As only one lens material is used, this design can easily be adapted for other wavelengths as 248 nm or 157 nm.


[0036] The intermediate image IMI is freely accessible, so that it is easily possible to insert a field stops. The aperture stop AP is located between lens surfaces 239 and 240 and is also well accessible.


[0037] The deflecting mirrors DM1 and DM2 in the catadioptric system CS are defined in their geometry by the demands of separation of the light beams to and from the concave mirror 209 and of clearance from lens 201, 202. It is advantageous that the mirror angle of mirror DM1 differs from 45°, such that the beam deflection angle is greater than 90°. This helps to ascertain large free working distance as well as wide clearance for the light beam relative to the first lens element 201, 202 and also gives full clearance of the lens barrel of the catadioptric systems CS from the object plane 0.


[0038] The arrangement of the two deflection mirrors DM1, DM2 allows for a straight optical axis and parallel situation of origin plane 0 and image plane IM, i.e. mask and wafer are parallel and can easily be scanned. However, one of the deflecting mirrors DM1, DM2 can be abandoned or eventually be replaced by a deflecting mirror in the refractive lens RL, e.g. in the air space between lens surfaces 225 and 226. It is also clear the deflecting mirrors can be replaced by other deflecting optical elements (as e.g. the prism in embodiment 6 or others).


[0039] A moderate positive lens 201, 202 is placed near the origin plane 0 in the single pass beam area. Its focal length is approximately equal to its distance from the concave mirror 209. This makes that the concave mirror 209 is situated in a pupil plane and thus the diameter required is minimized.


[0040] A second positive lens is located in the doubly passed area between the deflecting mirrors DM1, DM2 and the concave mirror 209. As the production conditions of concave mirrors of 200 mm to 300 mm diameter give no strong preference to smaller units—in contrast to lenses, namely such made from CaF2, where inhomogeneties etc. given strong limitations—there is no need to use this positive lens 203, 204 for reduction of the radius of the concave mirror 209. It is located nearer to the concave mirror 209 than to the first reflection mirror DM1 at a location where it serves best to minimize imaging errors.


[0041] The two negative menisci 205, 206; 207, 208 cooperate with the concave mirror 209 in a known manner, giving increased angles of incidence and stronger curvature, thus stronger correcting influence of the concave mirror 209.


[0042] It is significant, that the number of lenses in the doubly passed area of the catadoptric system CS is restricted to three, as here every lens counts doubly with respect to system energy transmission and wavefront quality degradation—without giving more degrees of freedom for correction.


[0043] Of a total reduction ratio of β=0.25 the catadioptric system CS delivers its part of βcs=1,008.


[0044] At the intermediate image plane IMI preferably a field stop FS is inserted, which reduces stray light favorably.


[0045] The refractive lens RL following to the intermediate image IMI is of more elaborate design than usual in the art. It is more of a quality as fully refractive projection exposure lenses of recent developments tend to be.


[0046] One can see that the five lens group design known from sophisticated refractive microlithography lens designs featuring two waists and three bellies with +−+−+ lens groups in this sequence is adopted. Though the first two bellies (lens surfaces 210 to 219, 224 to 227) are not very strongly expressed, the two waists W1, W2 are significantly established, each by a pair of negative menisci 220, 221; 222, 223 and 228, 229; 230, 231, whose convex surfaces face outwardly.


[0047] It is known that these lens groups at the waists W1, W2 as the others can be developed further by incorporating more lenses, e.g. to increase the numerical aperture or the image area.


[0048] From another point of view, the refractive lens RL is composed of a field lens group (lens surfaces 210 to 219) of positive power for turning the diverging chief ray into a converging chief ray, an image side positive focusing lens group (lens surfaces 232 to 251), which generates the required large numerical aperture, and intermediately arranged lens elements, which correct imaging errors, especially including sets of oppositely arranged negative menisci (w1, w2).


[0049] The −+ power doublets with surfaces 235 to 238 and 239 to 242 are the key to the wide spectral bandwidth at good correction of the chromatic variation in spherical aberration, which is the main residual aberration in these designs. It was found that the alternative arrangement there of +− power doublets gives much worse chromatic variation of spherical aberration. Here a value of 0, 35 μm is obtained at 15 pm laser bandwidth.


[0050] This example of FIG. 2 is suitable for printing microstructures at a resolution of less than 0.2 μm over an image field of 30×7 mm2 rectangle at 6 mm off axis, with an excimer laser source of 0.015 nm bandwidth.


[0051]
FIG. 3 and Table 2 show a design variant. The catadioptric system CS remains very similar, however its reduction ratio now is less than unity at βcs=0.944.


[0052] In the refractive lens the second lens 212, 213 of FIG. 2 is abandoned, while the thick negative lens 245, 246 is split into three units 342, 343; 344, 345; 346, 347.


[0053] Also two lenses now are made of CaF2, namely the elements with the surfaces 342, 343 and 348, 349. Related to the diameter of the greatest lens 330, 331 of ca. 250 mm their diameters of ca. 205 mm and approx. 165 mm are less than 0.81 fold and 0.67 fold. Therefore, their dimension is not too great and effective production is ascertained.


[0054] Also they are arranged in the converging light beam in the fifth lens group after the third belly, near the image plane. They help with achromatization. The other features are quite similar as those of the example of FIG. 2, including e.g. the −+ power doublets 332 to 339.


[0055]
FIG. 4 and table 3 show another example of a catadioptric lens according to the invention.


[0056] Now, the catadioptric system CS shows a major revision, as all lenses in the doubly passed region are combined into a single lens group next to the concave mirror 411. It includes the positive lens 403, 404 and three negative lenses 405 to 410. Change from two to three such negative lenses provides smoother increase of beam angles and thus optimizes correction. Thus, the construction of the lens barrel of the catadioptric system CS is simplified. The lenses 403 to 410 and the mirror 411 can be mounted in a compact unit of conventional construction as known from refractive projection exposure lenses. The long distance to the deflecting mirrors DM1, DM2 can be bridged by a thermally stable tubular body, e.g. made of fiber compound, glass ceramics or a bi-metal compound structure.


[0057] The positive lens 403, 404 now is made of fluorite (ca. 200 mm dia.), thus helping in achromatization. It is significant for the invention, that at most three to four lenses in total made of a second material are sufficient to provide good achromatization in this basic design.


[0058] The reduction ratio of the catadioptric system is βcs =0.931. The refractive lens system is constructed very similar to the one of table 2.


[0059] A fourth embodiment is given in FIG. 5 and table 4.


[0060] Now the catadioptric system CS again is free of any CaF2 element. Its principal construction with a compact unit of one positive (503, 504), three negative lenses (505-510) and the concave mirror 511 in one compact unit remains the same as in the third embodiment. The reduction ratio βcs is 0.961 in the most preferred range.


[0061] Also the refractive lens RL is of the same overall design as the before mentioned examples. However, the use of CaF2 lens elements has a novel character: While lens element 544, 545 in a known manner serves for achromatization, the reason for use of CaF2 in the two lenses 552, 553; 554, 555 next to the image plane IM is another one.


[0062] The reason for use of CaF2 here is the reduction of the “compaction” degradation effect which is rather strong with fused silica lenses at high light intensity and strong asymmetry (caused by narrow scanning image field) at 193 nm wavelength, but far less with CaF2 lenses (or other crystalline material).


[0063] With an overall length—object 0 to image IM—of 1455 mm, a deviation off the axis of the concave mirror 511 of 590 mm, diameter of the concave mirror 511 of 250 mm, greatest lens diameter in the refractive lens system RL of 240 mm (at lens 534, 535) and diameters of the CaF2 lenses of 195 mm (544, 545), 135 mm (552, 553) and 85 mm (554, 555) the dimensions of this construction are very acceptable. At Lambda =193 nm, 15 pm band width, reduction ratio 0.25, numerical aperture of 0.7, an image field of 26×9 mm2 rectangular is imaged at a resolution of better than 0.20 μm.


[0064] A fifth embodiment is given in FIG. 6a and table 5. This is distinguished from embodiment 4 in that only the last two lenses C1, C2 (654, 655; 656, 657) are made of CaF2 with the aim of reduction of long-time degradation by compaction of fused silica under 193 nm radiation, but no CaF2 is used for the purpose of achromatization.


[0065] The catadioptric system CS consists of a field lens 601, 602 with a focal length f′ related to its distance B to the concave mirror by f′/B=1.004.


[0066] Deflecting mirror DM1 deflects the optical axis. Its normal is tilted with respect to the optical axis by 50°. This gives better beam clearance from the field lens 601, 602 than the normal 45°.


[0067] The positive lens 603, 604 is combined with three negative lenses 605-610 and the concave mirror 611 into a compact unit. The distance DM1-603 is 432 MM, compared to the distance DM1-611 to the concave mirror of 597 mm; this is 72%.


[0068] The reduction ratio of the catadioptric system βcs 0.9608 lies in a preferable range near unity, where the achromatizing effect of the concave mirror is best exploited as well as other imaging errors (e.g. curvature of field) are kept small. The positive effect on Petzval sum is very good.


[0069] However, the concept of odd aberrations correction (Singh loc. cit.) is not adapted: At the intermediate image plane IMI the values of coma—0.1724—and distortion—0.0833—by far exceed good correction values, while at the final image plane IM coma (−0.00098) and distortion (−0.000115) are very well corrected, as other typical errors are.


[0070] A field stop FS at the intermediate image plane IMI advantageously cuts off disturbing stray light.


[0071] According to the invention the catadioptric system is designed with very few elements in compact arrangement for its function is focused on the implementation of the achromatizing and Petzval sum influence of the concave mirror 611.


[0072] Detailed correction is the realm of the refractive lens system RL. This is composed of a field lens group FL (surfaces 612 to 621) and a focusing lens group FG (surfaces 634 to 657). Correcting lens elements are inserted in between, including two pairs of opposing negative menisci 622-625 and 630-633. These form two beam waists W1, W2. Thus the +−+−+ five lens group design known from sophisticated refractive projection exposure lenses is established.


[0073] The focusing lens group FG hosts the system aperture AP as well as two −+ power lens groups PG1 and PG2 with the above-mentioned advantages.


[0074] No achromatizing CaF2 lens is provided, but as in embodiment 4 the two lenses C1, C2 (654-657) located next the image plane IM are made of CaF2 for the above mentioned reason of avoidance of compaction.


[0075] At a length of O-IM of 1400 mm and a sideward deviation of 590 mm to the concave mirror 611, the diameter of the concave mirror 611 (and the neighboring lens 609, 610) is limited to 252 mm, while the largest lens 636, 637 of the refractive lens system RL has a diameter of 240 mm and the CaF2 lenses have only 130 mm (C1) and 85 mm (C2) diameter. Thus requirements of production to avoid extreme diameters are well fulfilled.


[0076]
FIG. 6

b
shows the longitudinal spherical aberration and its chromatic variation at Lambda=193, 30 nm+0.015 nm for this embodiment 5, which as before mentioned is the remnant imaging error limiting the performance of this system.


[0077] It can be seen that with a moderately narrowed excimer laser source of Lambda=193.3 nm with 15 pm band width a rectangular field of 26×9 mm can be imaged at a resolution of better than 0.2 μm.


[0078] A sixth embodiment is shown in FIG. 7 and table 6. Here, a deflecting prism DP is inserted for deflecting the light path towards the concave mirror 711.


[0079] Since the light rays inside the prism DP spread apart less than when they are in air (or nitrogen or helium), the field size can be increased by a certain amount without introducing any vignetting of the light rays by the prism edges. The importance of this design modification increases at higher numerical Aperture. Vignetting of rays limits how large a field size can be handled by the folding elements, and even a relatively small increase in field size is very desirable—for a variety of reasons, including the possibility of shrinking all lens diameters for a given field required. It turns out not to be relevant to try this for the second flat mirror DM2. While FIG. 7 schematically shows the deflecting mirror region, exemplary lens data for a full system are given in table 6. This Prism arrangement can also help to extend the free working distance or to use other mirror angles (e.g. 45°).


[0080] Embodiment 7, for which design data are given in table 7, shows the possible extension of the image with side numerical aperture well beyond the 0.7 value of the other examples. The value of NA=0.8 is not yet limiting to this type of lens. The overall construction is as given in the other embodiments, thus no extra drawing is needed for explanation.


[0081] Embodiment 8 with lens data of table 8 gives a pure CaF2 deign for 157 nm wavelength as an example showing the possibilities of the inventive design for use with VUV wavelengths. The overall construction is very much like FIG. 6a.


[0082] Other combinations of claimed features than explicitly described above are within a scope of the invention.


[0083] The possibilities of the Schupman achromat for achromatization with only one lens material are fully exploited in embodiments 1 and 8. In consequence, this embodiment 8 presents the first 157 nm design of the Schupman achromat suitable for VUV lithography. Insertion of aspheres and consequent reduction of number and thickness of lenses will further optimize this.


[0084] A new aspect of using a second material in a lens for avoiding compaction is given in embodiments 4 to 7.


[0085] To simplify achromatization by use of a second material very few elements made from this are sufficient as embodiments 3, 4, 6 and 7 show.


[0086] Preferably the lenses between the deflecting elements and the concave mirror are arranged in a compact unit with the latter as in embodiments 3 to 8. All lenses are more distant from the deflecting elements than from the concave mirror, their minimal distances do not exceed their maximum thicknesses (both taken over the diameter), or the length of the compact unit does not exceed its diameter, at least not by more than 50%. The sophisticated design of the refractive lens system as presented allows for good correction at increased image side numerical apertures in the 0.65 to 0.85 range.


[0087] While examples are given for the scanning scheme of exposure, the invention as well is useful with step-and-repeat or stitching. Stitching allows for specifically smaller optics.
1TABLE 1Lambda = 193.3 nmβ = 0.25NA = 0.7No.RadiusThicknessGlass 0Infinity40.000201433.82320.000SIO2202Infinity76.000DM1Infinity286.798Angle 50.5°203371.25725.000SIO2204855.824216.212205−242.81315.000SIO2206−957.70229.987207−191.56315.000SIO2208−420.74412.000209267.741Reflector(203)281.798DM2Infinity141.534Angle 39.5°210341.60545.000SIO2211−302.3900.266212−314.72515.000SIO2213−535.92121.847214−293.71215.000SIO2215242.0742.808216253.64950.000SIO2217−418.7161.000218387.62132.000SIO2219Infinity23.536220338.43920.000SIO2221180.07356.252222−200.45217.000SIO2223−406.8721.000224830.48535.000SIO2225−406.246137.396226564.46632.000SIO2227−1292.8001.000228288.76422.000SIO2229169.29757.016230−189.64228.572SIO2231−398.13581.777232−476.26832.000SIO2233−238.6181.000234505.68417.000SIO2235259.77013.056236455.63838.000SIO2237−469.4181.000238236.17815.000SIO2239 = AP145.0302.543240149.63645.000SIO22411347.2001.000242138.08629.000SIO2243273.91916.837244−2450.80036.643SIO2245114.86812.598246183.26933.000SIO2247−427.0930.100248119.17756.567SIO2249352.5820.100250176.81742.544SIO2251−263.40215.000IMInfinity0.000


[0088]

2









TABLE 2













Lambda = 193.3 nm
β = −0.25
NA = 0.7














No.
Radius
Thickness
Glass





 0
Infinity
40.000


301
501.959
20.000
SIO2


302
6701.736
83.000


DM1
Infinity

Angle 53.00°


303
−477.089

SIO2


304
−5445.982


305
282.396

SIO2


306
1204.642


307
216.126

SIO2


308
519.194


309
298.619

Reflector


(303)


DM2
Infinity

Angle 37.00°


310
−277.399

SIO2


311
876.072


312
384.127

SIO2


313
−245.187


314
−297.630

SIO2


315
778.473


316
−422.020

SIO2


317
945.111


318
−336.194

SIO2


319
−169.717


320
208.247

SIO2


321
414.789


322
−639.842

SIO2


323
420.685


324
−508.419

SIO2


325
1843.176


326
−315.017

SIO2


327
−182.247


328
197.495

SIO2


329
764.726


330
572.623

SIO2


331
246.349


332
−592.087

SIO2


333
−240.082


334
−314.738

SIO2


335
745.437


336
−219.102

SIO2


337
−178.632


338
−269.565

SIO2


339 = AP
−8665.509


340
−165.739

SIO2


341
−378.291


342
−5121.046

CAF2


343
457.764


344
511.311

SIO2


345
−143.061


346
−134.125

SIO2


347
−125.446


348
−158.475

CAF2


349
451.948


350
−122.592

SIO2


351
−830.354


352
−374.272

SIO2


353
500.000


IM
Infinity










[0089]

3









TABLE 3













Lambda = 193.3 nm
β = −0.25
NA = 0.7














No.
Radius
Thickness
Glass













 0
Infinity
40.000



401
441.354
20.000
SIO2


402
−3082.575
82.000


DM1
Infinity
404.580
Angle 51°


403
379.755
40.000
CAF2


404
−503.571
10.819


405
−538.291
15.000
SIO2


406
−11216.000
23.000


407
−289.982
15.000
SIO2


408
1481.373
35.434


409
−212.610
15.000
SIO2


410
−422.622
10.747


411
281.484
10.747
Reflector


(403)

391.580


DM2
Infinity
95.000
Angle 39°


412
304.777
35.000
SIO2


413
−414.139
36.096


414
−217.633
15.000
SIO2


415
291.419
15.871


416
372.431
48.000
SIO2


417
−351.209
1.000


418
478.050
34.000
SIO2


419
−840.313
52.353


420
336.231
20.000
SIO2


421
175.364
55.562


422
−230.487
17.000
SIO2


423
−430.797
1.000


424
648.294
40.000
SIO2


425
−404.757
99.810


426
527.066
30.000
SIO2


427
−13296.000
1.000


428
288.592
22.000
SIO2


429
167.355
54.577


430
−201.179
20.000
SIO2


431
−801.011
103.872


432
−585.801
36.000
SIO2


433
−252.132
1.000


434
457.102
17.000
SIO2


435
260.610
9.580


436
343.579
43.000
SIO2


437
−739.447
1.000


438
226.319
18.500
SIO2


439
173.228
16.103


440
272.220
34.000
SIO2


441 = AP
−7972.902
1.000


442
165.067
34.000
SIO2


443
374.040
12.889


444
2219.918
22.000
CAF2


445
−490.695
0.100


446
−715.705
12.000
SIO2


447
134.285
0.100


448
123.907
36.879
SIO2


449
111.965
9.498


450
147.332
35.000
CAF2


451
−967.651
0.100


452
115.241
69.555
SIO2


453
921.256
0.100


454
294.383
28.447
SIO2


455
−500.000
15.000


IM
Infinity










[0090]

4









TABLE 4













Lambda = 193.3 nm
β = −0.25
NA = 0.7














No.
Radius
Thickness
Glass













 0
Infinity
35.000



501
407.048
16.000
SIO2


502
−85814.000
82.000


DM1
Infinity
431.676
Angle 50°


503
524.134
35.000
SIO2


504
−657.304
8.785


505
−587.479
15.000
SIO2


506
1940.811
25.643


507
−324.153
15.000
SIO2


508
−23676.000
37.709


509
−201.728
15.000
SIO2


510
−422.094
12.854


511
282.375

Reflector


(503)

422.676


DM2
Infinity
110.772
Angle 40°


512
373.692
35.000
SIO2


513
−410.297
50.772


514
−222.817
15.000
SIO2


515
317.101
6.370


516
349.335
48.000
SIO2


517
−362.479
1.000


518
729.698
34.000
SIO2


519
−931.019
57.653


520
371.363
20.000
SIO2


521
210.389
53.764


522
−248.647
17.000
SIO2


523
−428.501
1.000


524
937.198
40.000
SIO2


525
−388.007
113.824


526
567.461
30.000
SIO2


527
−4351.070
1.000


528
282.352
22.000
SIO2


529
185.586
56.362


530
−234.431
20.000
SIO2


531
−557.904
132.665


532
−408.165
35.442
SIO2


533
−266.966
1.000


534
404.076
17.000
SIO2


535
238.987
14.763


536
379.049
43.000
SIO2


537
−737.556
1.000


538
245.637
18.500
SIO2


539
178.878
12.206


540
245.508
34.000
SIO2


541
2061.364
10.000


AP
Infinity
0.000


542
168.071
34.000
SIO2


543
473.781
9.798


544
1851.461
22.000
CAF2


545
−494.253
0.100


546
−719.297
12.000
SIO2


547
132.814
0.100


548
127.155
34.780
SIO2


549
118.260
11.187


550
169.575
35.000
SIO2


551
−844.545
0.100


552
111.623
74.968
CAF2


553
1756.460
0.100


554
239.829
26.117
CAF2


555
−500.000
15.000


IM
Infinity
0.000










[0091]

5









TABLE 5













Lambda = 193.3 nm
β = −0.25
NA = 0.7














No.
Radius
Thickness
Glass













 0
Infinity
35.000



601
443.397
16.000
SIO2


602
−3263.101
82.000


DM1
Infinity
431.967
Angle 50°


603
510.641
35.000
SIO2


604
−953.685
12.327


605
−534.546
15.000
SIO2


606
1546.359
27.623


607
−295.422
15.000
SIO2


608
−1911.545
32.819


609
−212.072
15.000
SIO2


610
−404.269
12.229


611
279.883

Reflector


(603)

422.967


DM2
Infinity
109.448
Angle 40°


612
338.847
28.000
SIO2


613
−769.850
31.900


614
1373.814
18.000
SIO2


615
−915.108
37.909


616
−239.573
15.000
SIO2


617
279.202
6.538


618
301.416
46.477
SIO2


619
−437.969
1.000


620
722.212
30.074
SIO2


621
−1063.807
23.211


622
381.419
19.000
SIO2


623
193.859
52.872


624
−235.061
17.000
SIO2


625
−412.453
1.000


626
990.052
40.000
SIO2


627
−337.530
95.112


628
529.636
30.000
SIO2


629
−0.208
1.000


630
264.737
20.000
SIO2


631
173.477
55.898


632
−213.164
19.000
SIO2


633
−478.343
127.971


634
−384.253
29.998
SIO2


635
−241.972
1.000


636
381.178
17.000
SIO2


637
218.858
11.314


638
296.282
43.000
SIO2


639
−966.118
1.000


640
230.570
18.500
SIO2


641
172.880
14.657


642
271.493
30.000
SIO2


643
−49526.000
4.000


AP
Infinity
0.000


644
156.048
36.000
SIO2


645
474.860
12.986


646
−4892.676
20.000
SIO2


647
−452.665
0.100


648
−711.904
34.541
SIO2


649
122.051
9.933


650
171.475
33.021
SIO2


651
−967.318
0.100


652
112.494
72.297
CAF2


653
3642.643
0.100


654
250.427
26.033
CAF2


655
−500.000
15.000


IM
Infinity
0.000










[0092]

6









TABLE 6













Lambda = 193.3 nm
β = −0.25
NA = 0.7














No.
Radius
Thickness
Glass













 0
Infinity
35.000



701
396.818
16.000
SIO2


702
−411120.000
1.000


DP
Infinity
85.500
SIO2


DP
Infinity
435.933
Angle 50°


703
559.897
35.000
SIO2


704
−763.942
2.707


705
−627.112
15.000
SIO2


706
2056.900
24.065


707
−323.749
15.000
SIO2


708
−4114.500
41.268


709
−197.452
15.000
SIO2


710
−416.693
13.024


711
278.696

Reflector


(703)

420.933


DM2
Infinity
84.857
Angle 40°


712
391.689
35.000
SIO2


713
−391.139
54.674


714
−217.120
15.000
SIO2


715
328.292
6.584


716
363.974
48.000
SIO2


717
−352.092
11.973


718
753.003
34.000
SIO2


719
−915.634
62.045


720
369.054
20.000
SIO2


721
218.165
56.274


722
−247.872
17.000
SIO2


723
−420.231
1.000


724
970.166
40.000
SIO2


725
−383.655
110.429


726
556.298
30.000
SIO2


727
−5145.200
1.000


728
275.093
22.000
SIO2


729
186.724
57.861


730
−249.939
24.499
SIO2


731
−573.695
138.278


732
−424.514
35.114
SIO2


733
−274.834
1.000


734
391.263
17.000
SIO2


735
226.128
16.728


736
383.272
43.000
SIO2


737
−863.203
1.000


738
239.284
18.500
SIO2


739
178.197
11.299


740
237.727
34.000
SIO2


741
1618.000
10.000


AP
Infinity
0.000


742
165.688
34.000
SIO2


743
445.266
9.217


744
1247.900
22.000
CAF2


745
−503.423
0.000


746
−771.731
12.000
SIO2


747
131.678
0.100


748
124.872
29.133
SIO2


749
115.885
13.283


750
179.986
35.000
SIO2


751
−802.711
0.100


752
110.497
77.422
CAF2


753
2393.500
0.100


754
234.953
25.804
CAF2


755
−500.000
15.000


IM
Infinity
0.000










[0093]

7









TABLE 7













Lambda = 193 nm
β = −0.25
NA = 0.8














No.
Radius
Thickness
Glass













 0
Infinity
35.000



801
355.625
15.000
SIO2


802
Infinity
84.000


DM1
Infinity
393.919
Angle 50°


803
621.321
30.000
SIO2


804
17349.000
15.577


805
−522.771
15.000
SIO2


806
7450.061
28.795


807
−279.969
15.000
SIO2


808
−692.552
26.633


809
−231.205
15.000
SIO2


810
−419.760
13.994


811
283.256

Reflector


(803)

384.919


DM2
Infinity
103.131
Angle 40°


812
363.520
35.000
SIO2


813
−312.546
19.745


814
−203.460
15.000
SIO2


815
417.901
4.913


816
637.371
44.999
SIO2


817
−299.660
1.000


818
670.513
36.000
SIO2


819
−607.949
99.443


820
409.543
20.000
SIO2


821
184.175
56.726


822
−190.739
18.000
SIO2


823
−300.666
1.000


824
2541.548
35.000
SIO2


825
−423.211
82.343


826
529.976
40.000
SIO2


827
−575.433
1.000


828
338.904
22.000
SIO2


829
161.992
77.036


830
−180.233
20.000
SIO2


831
−286.886
60.230


832
1358.390
50.000
SIO2


833
−310.335
1.000


834
299.546
17.000
SIO2


835
185.330
22.475


836
318.393
15.000
SIO2


837
240.343
11.470


838
351.936
35.000
SIO2


839
−1892.972
1.000


840
241.744
18.500
SIO2


841
201.167
6.992


842
233.761
35.000
SIO2


843
1187.547
0.000


AP
Infinity
6.993


844
173.633
65.000
CAF2


845
−647.630
0.100


846
−1026.314
15.000
SIO2


847
134.041
12.672


848
177.508
43.000
SIO2


849
−552.796
0.100


850
111.087
82.051
CAF2


851
366.445
0.100


852
201.556
9.977
CAF2


853
Infinity
15.000


IM
Infinity










[0094]

8









TABLE 8













Lambda 157.000 nm ± 2 pm
NA = 0.7
β = −0.25














No.
Radius
Thickness
Glass













 0
Infinity
35.000



901
509.596
16.000
CAF2


902
−1709.182
82.000


DM1
Infinity
430.770
Angle 50°


903
559.504
35.000
CAF2


904
−1229.460
18.117


905
−727.847
15.000
CAF2


906
1261.260
27.332


907
−297.498
15.000
CAF2


908
−1565.150
32.707


909
−205.835
15.000
CAF2


910
−396.253
12.181


911
279.103
Reflector
φ 252 mm


(903)

420.578


DM2
Infinity
73.026
Angle 40°


IMI
Infinity
34.034


912
341.070
28.000
CAF2


913
−1505.473
32.408


914
969.048
18.000
CAF2


915
−805.764
37.523


916
−248.947
15.000
CAF2


917
286.272
5.893


918
307.931
45.973
CAF2


919
−386.903
1.000


920
1003.377
28.290
CAF2


921
−945.839
20.042


922
397.781
19.000
CAF2


923
197.943
53.200


924
−231.060
17.000
CAF2


925
−406.748
1.000


926
878.953
40.000
CAF2


927
−351.000
100.639


928
481.080
30.000
CAF2


929
11551.730
1.000


930
282.768
20.000
CAF2


931
179.880
51.341


932
−217.737
19.000
CAF2


933
−511.417
127.776


934
−377.857
29.786
φ240 mm CAF2


935
−241.099
1.000


936
377.020
17.000
CAF2


937
218.220
11.262


938
299.020
43.000
CAF2


939
−943.927
1.000


940
228.020
18.500
CAF2


941
168.921
13.866


942
263.149
30.000
CAF2


943
−27570.214
0.752


AP
Infinity
8.754


944
157.192
36.000
CAF2


945
476.977
13.281


946
−5291.918
20.000
CAF2


947
−428.700
0.100


948
−634.165
34.624
CAF2


949
123.520
10.454


950
180.781
33.303
CAF2


951
−732.821
0.100


952
115.913
72.125
CAF2


953
3615.409
0.100


954
308.142
25.802
CAF2


955
−500.000
15.000


IM
Infinity












Refractive Indices CaF2











Lambda = 157.002
157.000
156.998



n = 1.560047
1.560052
1.560057











Claims
  • 1. A projection exposure lens system, comprising: a catadioptric system, an intermediate image, and a refractive lens system, with lenses made of a first material and lenses made of a second material, in which no more than four lenses are made of said second material.
  • 2. The projection exposure lens system according to claim 1, in which no more than three lenses are made of said second material.
  • 3. A projection exposure lens system, comprising: a catadioptric system, an intermediate image, and a refractive lens system, in which said catadioptric system has at least one deflecting element, a concave mirror and a plurality of lenses between said at least one deflecting element and said concave mirror, and in which said concave mirror and all lenses arranged between said deflecting element and said concave mirror are arranged in a compact unit.
  • 4. A projection exposure lens system, comprising: a catadioptric system, in which said catadioptric system has at least one deflecting element, at least one concave mirror and a plurality of lenses, and in which said catadioptric system has at least one positive lens between an object and a first deflecting element, and not more than one positive and not more than three negative lenses between said first deflecting element and said concave mirror.
  • 5. A projection exposure lens system comprising: a catadioptric system, and intermediate image and a refractive lens system, in which said refractive lens system from its intermediate image side and in the direction of its image plane has a first lens group of positive refractive power, a second lens group of negative refractive power, a third lens group of positive refractive power, a fourth lens group of negative refractive power, and a fifth lens group of positive refractive power.
  • 6. A projection exposure lens system comprising: a catadioptric system, an intermediate image, and a refractive lens system, in which at least one −+ power doublet with a negative power lens and a positive power lens in this sequence from an object side is arranged in said refractive lens system.
  • 7. A projection exposure lens system comprising: a catadioptric system, an intermediate image, and a refractive lens system, in which said refractive lens system comprises a field lens group, an intermediate correcting lens group and a focussing lens group.
  • 8. A projection exposure lens system comprising: a catadioptric system, an intermediate image, and a refractive lens system, in which said catadioptric system has an imaging ratio of greater than 0.95, and different from unity.
  • 9. The projection exposure lens system according to claim 1, in which said refractive lens system contains at least a pair of menisci, the convex surface of an intermediate-image-side meniscus facing said intermediate image, the convex surface of the other meniscus facing oppositely.
  • 10. The projection exposure lens system according to claim 9, in which said at least one pair of menisci is arranged in a correcting lens group.
  • 11. The projection exposure lens system according to claim 7, in which one of said −+ power doublets is arranged in a focussing lens group.
  • 12. A projection exposure lens system, comprising: a refractive lens system and on an object side of the refractive lens system a catadioptric system generating an intermediate image, with lenses made of a first material and lenses made of a second material, in which no more than four lenses are made of said second material.
  • 13. The projection exposure lens system according to claim 12, in which no more than three lenses are made of said second material.
  • 14. A projection exposure lens system, comprising: a refractive lens system and on an object side of the refractive lens system a catadioptric system generating an intermediate image, with lenses made of a first material and lenses made of a second material, in which no more than four lenses are made of said second material, in which said catadioptric system has at least one deflecting element, a concave mirror and a plurality of lenses between said at least one deflecting element and said concave mirror, and in which said concave mirror and all lenses arranged between said deflecting element and said concave mirror are arranged in a compact unit.
  • 15. A projection exposure lens system comprising: a refractive lens system and on an object side of the refractive lens system a catadioptric system generating an intermediate image, with lenses made of a first material and lenses made of a second material, in which no more than four lenses are made of said second material, in which said refractive lens system from its intermediate image side and in the direction of its image plane has a first lens group of positive refractive power, a second lens group of negative refractive power, a third lens group of positive refractive power, a fourth lens group of negative refractive power, and a fifth lens group of positive refractive power.
  • 16. A projection exposure lens system comprising: a refractive lens system and on an object side of the refractive lens system a catadioptric system generating an intermediate image, with lenses made of a first material and lenses made of a second material, in which no more than four lenses are made of said second material, in which at least one −+ power doublet with a negative power lens and a positive power lens in this sequence from an object side is arranged in said refractive lens system.
  • 17. A projection exposure lens system comprising: a refractive lens system and on an object side of the refractive lens system a catadioptric system generating an intermediate image, with lenses made of a first material and lenses made of a second material, in which no more than four lenses are made of said second material, in which said refractive lens system comprises a field lens group, an intermediate correcting lens group and a focusing lens group.
  • 18. A projection exposure lens system, comprising: a refractive lens system and on an object side of the refractive lens system a catadioptric system generating an intermediate image, with lenses made of a first material and lenses made of a second material, in which no more than four lenses are made of said second material, in which said catadioptric system has an imaging ratio of greater than 0.95, and different from unity.
  • 19. The projection exposure lens system according to claim 12, in which said refractive lens system contains at least a pair of menisci, the convex surface of an intermediate-image-side meniscus facing said intermediate image, the convex surface of the other meniscus facing oppositely.
  • 20. The projection exposure lens system according to claim 19, in which said at least one pair of menisci is arranged in a correcting lens group.
  • 21. The projection exposure lens system according to claim 17, in which one of said −+ power doublets is arranged in a focusing lens group.
  • 22. A projection exposure lens system comprising a refractive lens system with a first lens second next to its image plane and a second lens next to its image plane, said first lens being concave on its image ward surface, said second lens being convex on its surface facing said first lens, said concave surface and said convex surface being substantially concentric.
  • 23. A system according to claim 22, said first lens being a meniscus lens.
  • 24. A system according to claim 22, said second lens being a plano-convex lens.
  • 25. A system according to claim 22, said first lens and said second lens both being of the same material.
  • 26. A system according to claim 25, said material being CaF2 .
  • 27. A system according to claim 22, an axial distance between said first and second lens being of the order of magnitude of one millimeter.
  • 28. A system according to claim 22, a difference of ratio of said concave and said convex surface being of the order of magnitude of one millimeter.
  • 29. The projection exposure lens system according to claim 6, in which one of said −+ power doublets is arranged next to a system aperture.
  • 30. The projection exposure lens system according to claim 1, in which no more than one lens of said catadioptric system is made of said second lens material.
  • 31. The projection exposure lens system according to claim 1, in which the diameter of lenses made of said second lens material does not exceed a 0.85 fold of the diameter of a biggest optical element.
  • 32. The projection exposure lens system according to claim 1, in which the diameter of lenses made of said second lens material does not exceed 220 mm.
  • 33. The projection exposure lens system according to claim 1, in which said catadioptric system contains no more than six lenses.
  • 34. The projection lens system according to claim 16, in which said catadioptric system contains no more than five lenses.
  • 35. The projection exposure lens system according to claim 1, in which longitudinal chromatic aberration is less than 0.015 μm per a band width of 1 pm at 193 nm.
  • 36. The projection exposure lens according to claim 1, in which longitudinal chromatic aberration is less than 0.05 μm per a band width of 1 pm at 157 nm.
  • 37. The projection exposure lens system according to claim 1, in which an imaging ratio of said catadioptric system is greater than 0.8.
  • 38. The projection exposure lens system according to claim 21, in which said imaging ratio of said catadioptric system is greater than 0.95.
  • 39. The projection exposure lens according to claim 1, in which in said refractive lens system all lenses made of said second lens material are arranged in a converging light beam next to an image plane.
  • 40. The projection exposure lens system according to claim 1, in which said projection exposure lens system is both side telecentric.
  • 41. The projection exposure lens system according to claim 6, having at least one beam waist in a refracting subsystem, and said −+ power doublets are arranged behind a last beam waist.
  • 42. The projection exposure lens system according to claim 6, in which said −+ doublets are arranged such that a light beam diameter inside lens elements of said −+ doublets is more than 80% of a maximum beam diameter.
  • 43. The projection exposure lens system according to claim 1, further comprising a concave mirror in said catadioptric lens system, and a reflecting prism inserted for reflection of a light beam between an object and said concave mirror.
  • 44. The projection exposure lens system according to claim 1, in which said projection exposure lens system is designed for use with one of 248 nm and 193 nm light and said first material comprises fused silica and said second material comprises calcium fluoride.
  • 45. The projection exposure lens system according to claim 1, in which said first material comprises calcium fluoride.
  • 46. The projection exposure lens system according to claim 1, further comprising a first deflecting element in said catadioptric lens system, in which exactly one lens is placed between an object and said first deflecting element.
  • 47. The projection exposure lens system according to claim 29, in which the ratio of focal length of said one lens before said first deflecting element over the distance from said one lens to said deflecting element is unity within (+/−) fifteen percent.
  • 48. A projection exposure apparatus, comprising: a projection exposure lens system according to claim 1, an excimer laser light source, an illuminating system, a mask handling and positioning system, and a wafer handling and positioning system.
  • 49. A method of producing microstructured devices by lithography comprising using a projection exposure apparatus according to claim 31.
  • 50. The method according to claim 32, further comprising using one of step- and repeat, scanning, and stitching exposure schemes.
Parent Case Info

[0001] This is a Continuation of U.S. patent application Ser. No. 10/079,964 filed on Feb. 20, 2002, of the same inventors. This Continuation Application claims the benefit of U.S. patent application Ser. No. 10/079,964 under 35 USC 120.

Continuations (1)
Number Date Country
Parent 10079964 Feb 2002 US
Child 10787809 Feb 2004 US