Patent EP0102728A1 successfully refreshed from Google Patents.
Patent EP0489426B1 successfully refreshed from Google Patents.
EP0489426B1
Expired / Lapsed
EP
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Projection exposure method
Assignee: Sony Corp
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Filing: 1991-12-04
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Granted: 1997-08-20
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Expires: 2011-12-04
Abstract
No abstract record available.
Inventors
- 👤 Tetsuya Kitagawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 19:12
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70216; G03F7/70325; G03F7/70333; H; H10; H10P; H10P34/00; H10P34/40; G03F7/20; G03F7/2022; G03F7/70241; G03F7/70358
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
87 words
A method for projection exposure of projecting a photomask (5) pattern on a wafer (10) by a projection optical system (1-4,6) comprising setting an image plane of said pattern on said wafer (10) at three or more positions along the optical axis of said optical system (1-4,6) within a predetermined extent, and carrying out light exposure operations sequentially at these positions, characterized in that the exposure light volume at or near the mid point of said extent is smaller than that at both ends of said extent.
Claim 2
Dependent Claim
22 words
The method as claimed in claim 1 wherein setting of said image plane is performed by driving said projection optical system (1-4,6).
Claim 3
Dependent Claim
20 words
The method as claimed in claim 1 wherein setting of said image plane is performed by driving said photomask (5).
Claim 4
Dependent Claim
22 words
The method as claimed in claim 1 wherein setting of said image plane is performed by driving (see 8) said wafer (10).
References Cited (Backward Citations)
No citation records indexed.
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