Optical: systems and elements – Lens – With field curvature shaping
Reexamination Certificate
2003-03-20
2004-09-14
Sugarman, Scott J. (Department: 2873)
Optical: systems and elements
Lens
With field curvature shaping
C359S754000, C359S683000
Reexamination Certificate
active
06791761
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention generally relates to an optical projection system comprising a light source, a mask holder, a projection lens system, and specifically relates to an optical projection system for photolithography used in producing microstructured devices, i.e., microlithography, such as integrated circuits or other semiconductor devices. During the fabrication of such devices, photolithography transfers an image from a photographic mask to a resultant pattern on a semiconductor wafer. Such photolithography generally includes a light exposure process, in which a semiconductor wafer is exposed to light having information of a mask pattern. Optical projection systems are used to perform the light exposure process.
In general, the transferred mask patterns are very fine, so that optical projection lens systems are required to have a high resolution. The high resolution necessitates a large numerical aperture of the optical projection lens system and also nearly no aberration of the optical projection lens system in the light exposure field.
For example, some projection lens systems are proposed in the German Patent Application DE 198 18 444 A1. The shown projection lens system comprises 6 lens groups. The first, third, fifth and sixth lens groups have positive refractive power and the second and fourth lens groups have negative refractive power. To get a high resolution in all shown examples, aspherical surfaces are in the fourth and fifth lens groups.
Some purely refractive projection exposure objectives of microlithography are discussed in SPIE Vol. 237 (1980), page 310 ff. There are shown objectives of the planar style and the distagon style, wherein the new style of objective comprises two waists for setzval correction.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a further excellent optical projection lens system for photolithography.
The optical projection lens system of the invention comprises in a direction of the light (propagating radiation) a first lens group having positive refractive power and a second lens group having negative refractive power and establishing a beam waist (i.e., constriction) of minimal beam height. A further lens arrangement follows the second lens group. At least one lens, which is arranged before the first beam waist, has an aspherical surface. Further, lenses comprising aspherical surfaces in all other groups will be helpful to reduce the needed amount of material and to reduce the length of the optical projection lens system.
REFERENCES:
patent: 5059006 (1991-10-01), Kikuchi et al.
patent: 5260832 (1993-11-01), Togino et al.
patent: 5398064 (1995-03-01), Saka
patent: 5414561 (1995-05-01), Wakimoto et al.
patent: 5623365 (1997-04-01), Kuba
patent: 5636000 (1997-06-01), Ushida et al.
patent: 5696631 (1997-12-01), Hoffman
patent: 5856884 (1999-01-01), Mercado
patent: 5969803 (1999-10-01), Mercado
patent: 5986824 (1999-11-01), Mercado
patent: 5990926 (1999-11-01), Mercado
patent: 6008884 (1999-12-01), Yamaguchi et al.
patent: 6084723 (2000-07-01), Matsuzawa et al.
patent: 6088171 (2000-07-01), Kudo
patent: 6166865 (2000-12-01), Matsuyama
patent: 6185050 (2001-02-01), Ota et al.
patent: 6198576 (2001-03-01), Matsuyama
patent: 6259508 (2001-07-01), Shigematsu
patent: 6259569 (2001-07-01), Kasai
patent: 6349005 (2002-02-01), Schuster et al.
patent: 6377338 (2002-04-01), Suenaga
patent: 6512633 (2003-01-01), Konno et al.
patent: 6538821 (2003-03-01), Takahashi
patent: 6560031 (2003-05-01), Shafer et al.
patent: 6606144 (2003-08-01), Omura
patent: 6674513 (2004-01-01), Omura
patent: 2003/0086183 (2003-05-01), Wagner et al.
patent: 1 235 092 (2002-08-01), None
patent: 1 237 043 (2002-09-01), None
patent: 1 245 984 (2002-10-01), None
patent: 1088192 (1967-10-01), None
patent: 10-282411 (1998-10-01), None
patent: 10-325922 (1998-12-01), None
patent: 11-006957 (1999-01-01), None
patent: 11-095095 (1999-04-01), None
patent: 11-214293 (1999-08-01), None
Bruning, John H. et al., “Optical Lithography—Thirty years and three orders of magnitude, The evolution of optical lithography tools”,SPIE, vol. 3049, pp. 14-27 (1997).
Buckley, Jere D. et al., “Step and Scan: A systems overview of a new lithography tool”,SPIE, vol. 1088, pp. 424-433 (1989).
Glatzel, E., “New Developments in Photographic Objectives”,Offprint from Optical Instruments and Techniques, Oriel Press, pp. 413-415 (1969).
Glatzel, Erhard, “New Lenses for Microlithography”,SPIE, vol. 237, pp. 310-320 (1980).
Sheats, James R. et al.,Microlithography Science and Technology, pp. 263-270.
Wöltche, Walter, “Optical Systems Design with Reference to the Evolution of the Double Gauss Lens”,SPIE, vol. 237, pp. 202-215 (1980).
Shafer David R.
Ulrich Wilhelm
Hasan M.
Sugarman Scott J.
Zeiss SMT AG
LandOfFree
Optical projection lens system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Optical projection lens system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical projection lens system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3273592