US5563012A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multi mask method for selective mask feature enhancement
Assignee: International Business Machines Corp
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Filing: 1994-06-30
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Granted: 1996-10-08
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Expires: 2014-06-30
Abstract
Abstract The preferred embodiment of the present invention is a method of enhancing normally unenhanced features types. Pattern shapes are placed on two or more relatively simple, modified masks instead of using a single mask containing diverse feature types. On these modified masks, (hereinafter "overlay masks"), all of the features are the type normally enhanced. A composite pattern is printed into photoresist through successive exposure to the overlay masks.
Inventors
- 👤 Mark O. Neisser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:47
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/26; G03F1/32; G03F1/29; G03F1/68; G03F1/70; G03F7/00; G03F7/20; G03F7/2022; G03F7/70; G03F7/70425; G03F7/70466
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
111 words
A method of image enhancement of a pattern having diverse feature types, said method comprising: grouping pattern shapes into a plurality of shape groups according to feature type, said plurality of shape groups including at least one enhanced feature group and at least one unenhanced feature group; forming a plurality of overlay groups from at least one unenhanced feature group; forming a plurality of overlay masks, each said overlay mask including a different one of said plurality of overlay groups, and, one of said overlay masks including said at least one enhanced feature group; and successively exposing the overlay masks on a photosensitive layer without intermediate development of the photosensitive layer.
Claim 2
Independent Claim
111 words
A method of image enhancement of a pattern having diverse feature types, said method comprising: grouping pattern shapes into a plurality of shape groups according to feature type, said plurality of shape groups including at least one enhanced feature group and at least one unenhanced feature group; forming a plurality of overlay groups from at least one unenhanced feature group; forming a plurality of overlay masks, each said overlay mask including a different one of said plurality of overlay groups, and, one of said overlay masks including said at least one enhanced feature group; and successively exposing the overlay masks on a photosensitive layer without intermediate development of the photosensitive layer.
Claim 3
Dependent Claim
33 words
The method of claim 1 wherein said plurality of shape groups is two shape groups, said plurality of overlay groups is 2 overlay groups, and said plurality of overlay masks is two masks.
Claim 4
Dependent Claim
60 words
The method of claim 2 wherein said 2 overlay groups is formed by replicating shapes in said unenhanced feature group into two arrays of said shapes, one said array in each said overlay group, whereby shapes in both said overlay groups interleave when said masks are overlain, cancelling said replicated shapes out and forming said pattern in a photoresistive layer.
Claim 5
Dependent Claim
23 words
The method of claim 3 wherein said overlay masks are off-axis illumination masks and said unenhanced feature type is an isolated feature type.
Claim 6
Dependent Claim
56 words
The method of claim 3 wherein said one of said overlay groups is formed by replicating isolated shapes in said unenhanced group on a predetermined pitch to form an array, and the second said overlay group is formed by replicating said isolated shapes and shifting said replicated isolated shapes by one half the pitch of replication.
Claim 7
Dependent Claim
46 words
The method of claim 2 wherein said 2 overlay groups are formed by grouping shapes in said unenhanced feature group into two subgroups, such that when said overlay masks are overlain, said two subgroups are interleaved, and pattern images in said unenhanced feature group are formed.
Claim 8
Dependent Claim
22 words
The method of claim 6 wherein said overlay masks are phase shift masks and said feature type is an array feature type.
Claim 9
Dependent Claim
14 words
The method of claim 6 wherein said overlay masks are attenuated phase shift masks.
Claim 10
Dependent Claim
12 words
The method of claim 6 wherein said overlay masks are Rim masks.
Claim 11
Independent Claim
59 words
A method of semiconductor chip manufacture comprising: forming a first portion of an array in a resist layer, said first portion comprising at least a first isolated image; and forming a second portion of an array in said resist layer, said second portion comprising at least a second isolated image, said second portion being interleaved with said first portion.
Claim 12
Independent Claim
59 words
A method of semiconductor chip manufacture comprising: forming a first portion of an array in a resist layer, said first portion comprising at least a first isolated image; and forming a second portion of an array in said resist layer, said second portion comprising at least a second isolated image, said second portion being interleaved with said first portion.
Claim 13
Dependent Claim
27 words
The method of claim 10 wherein a phase shift mask is used to expose said resist layer to form said first and second portions of said array.
Claim 14
Independent Claim
63 words
A method of semiconductor chip manufacture comprising: forming a first array layer in a resist layer; and forming a second array in said resist layer, said second array being interleaved with said first array such that said first and second arrays merge to form uniform exposure except in at least one predetermined area, said at least one predetermined area forming an isolated shape.
Claim 15
Independent Claim
63 words
A method of semiconductor chip manufacture comprising: forming a first array layer in a resist layer; and forming a second array in said resist layer, said second array being interleaved with said first array such that said first and second arrays merge to form uniform exposure except in at least one predetermined area, said at least one predetermined area forming an isolated shape.
Claim 16
Dependent Claim
51 words
The method of claim 12 wherein each of said first and second arrays comprise at least one desired feature and at least one dummy feature, off-axis illumination is used to expose said resist layer to form said first and second arrays, and wherein said isolated shape corresponds to said desired pattern.
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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) | 1999-10-08 | 2000-04-08 | 2000-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-10-08 | 2004-04-08 | 2004-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-10-08 | 2008-04-08 | 2008-10-08 | $7700.00 | Window Closed / Lapsed |