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US5973767A
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Off-axis illuminator lens mask for photolithographic projection system
Assignee: Bell Semiconductor LLC
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Filing: 1998-06-26
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Granted: 1999-10-26
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Expires: 2018-06-26
Abstract
Abstract The present invention provides for novel off-axis illuminator lens masks for semiconductor photolithographic projection systems. The masks are rotationally symmetric along axes 60° or 120° apart. Such masks can increase the contrast 30° and 60° with respect to the X and Y axes of an integrated circuit in a semiconductor wafer for the optimum printing of conducting lines along these directions.
Inventors
- 👤 Nicholas F. Pasch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:38
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70058; G03F7/70091; G03F7/701
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
125 words
An improved semiconductor wafer photolithographic system for projecting an image pattern onto a semiconductor wafer, said system comprising: an optical source for generating light; a mask defining said image pattern; an illuminator lens disposed between said optical source and said mask for illuminating said image pattern from said optical source light; primary lens disposed between said mask and said semiconductor water for focussing said image pattern from said mask onto said semiconductor wafer; and an off-axis illuminator lens mask mounted between said optical source and said illuminator lens, centered about a central optical axis, said mask having a plurality of discrete transmissive portions and a contiguous opaque portion, said transmissive portions being spaced at 60 degree or 120 degree intervals with respect to each other.
Claim 2
Dependent Claim
125 words
An improved semiconductor wafer photolithographic system for projecting an image pattern onto a semiconductor wafer, said system comprising: an optical source for generating light; a mask defining said image pattern; an illuminator lens disposed between said optical source and said mask for illuminating said image pattern from said optical source light; primary lens disposed between said mask and said semiconductor water for focussing said image pattern from said mask onto said semiconductor wafer; and an off-axis illuminator lens mask mounted between said optical source and said illuminator lens, centered about a central optical axis, said mask having a plurality of discrete transmissive portions and a contiguous opaque portion, said transmissive portions being spaced at 60 degree or 120 degree intervals with respect to each other.
Claim 3
Dependent Claim
24 words
The improved semiconductor wafer photolithographic system of claim 1 wherein said pattern of said off-axis illuminator lens mask has transmissive portions along said axes.
Claim 4
Dependent Claim
56 words
For a semiconductor wafer photolithographic projection device, an off-axis illuminator lens mask centered about a central optical axis, comprising a substantially flat surface having a pattern thereon comprised of a plurality of discrete transmissive portions and an opaque portion, said discrete transmissive portions being spaced at 60 degrees or 120 degrees with respect to each other.
Claim 5
Dependent Claim
56 words
For a semiconductor wafer photolithographic projection device, an off-axis illuminator lens mask centered about a central optical axis, comprising a substantially flat surface having a pattern thereon comprised of a plurality of discrete transmissive portions and an opaque portion, said discrete transmissive portions being spaced at 60 degrees or 120 degrees with respect to each other.
Claim 6
Dependent Claim
23 words
The off-axis illuminator lens mask of claim 3 wherein said pattern of said off-axis illuminator lens mask has transmissive portions along said axes.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-10-25 | 2003-04-26 | 2003-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-10-25 | 2007-04-26 | 2007-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-10-25 | 2011-04-26 | 2011-10-26 | $7700.00 | Window Closed / Lapsed |