Title:
PROJECTION EXPOSURE METHOD AND APPARATUS AND PROJECTION OPTICAL SYSTEM
Document Type and Number:
WIPO Patent Application WO/2001/023935
Kind Code:
A1
Abstract:
A refractive projection optical system preferable to a projection exposure apparatus used at a lithography step when a microdevice such as a semiconductor device is fabricated. The projection optical system comprises a positive front lens group (GF), an aperture stop (AS), and a positive rear lens group (GR) and is a both-side telecentric optical system. The relationship between the focal length f2 of the rear lens group (GR) and the overall distance L is 0.065 < f2 / L < 0.125. The projection optical system includes at least one aspherical surface (ASP1-ASP6).
Inventors:
OMURA YASUHIRO (JP)
Application Number:
PCT/JP2000/006706
Publication Date:
April 05, 2001
Filing Date:
September 28, 2000
Export Citation:
Assignee:
NIPPON KOGAKU KK (JP)
OMURA YASUHIRO (JP)
OMURA YASUHIRO (JP)
International Classes:
G02B13/14; G02B13/18; G02B13/22; G02B13/24; G03F7/20; (IPC1-7): G02B13/24; G02B13/18; H01L21/027; G03F7/20
Foreign References:
| JPH11133301A | 1999-05-21 | |||
| US5808814A | 1998-09-15 | |||
| JPH09329742A | 1997-12-22 |
Other References:
See also references of EP 1139138A4
Attorney, Agent or Firm:
Omori, Satoshi (Noborito Tama-ku Kawasaki-shi, Kanagawa, JP)
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