US5424154A
Expired / Lapsed
US
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Lithographic emhancement method and apparatus for randomly spaced structures
Assignee: Intel Corp
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Filing: 1993-12-10
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Granted: 1995-06-13
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Expires: 2013-12-10
Abstract
Abstract A method of enhancing the lithographic resolution of randomly laid out isolated structures is disclosed. A first mask comprises an active layer with isolated features such as gates. Portions of the active layer have a reduced dimension typical of periodic structures. The first mask additionally has complementary features provided along side the reduced active features to provide periodicity. In this way, the resolution of the lithographic process is enhanced, and other enhanced resolution technologies additionally can be used to best advantage to form a patterned photosensitive layer having isolated features of reduced width. The photosensitive layer is then exposed to a second mask which exposes the complementary features so that they are removed from the latent image in the photosensitive layer. This second exposure also further improves resolution by enhancing the contrast between exposed and unexposed regions. A method is disclosed for automatically providing random logic device layouts having the complementary features, as well as for providing a layout for the second mask.
Inventors
- 👤 Yan A. Borodovsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:47
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/26; G03F1/68; G03F1/70; G03F7/00; G03F7/70; G03F7/70058; G03F7/70125; G03F7/70216; G03F7/70283
Claims Analysis
Total Claims: 49
Claim 1
Independent Claim
67 words
A method of patterning a feature in a photosensitive layer comprising the steps of: exposing said photosensitive layer to a first mask, said first mask having an active feature and a first complementary feature proximate at least a portion of said active feature along a first edge of said active feature; exposing said photosensitive layer to a second mask, said second mask exposing said first complementary feature.
Claim 2
Independent Claim
67 words
A method of patterning a feature in a photosensitive layer comprising the steps of: exposing said photosensitive layer to a first mask, said first mask having an active feature and a first complementary feature proximate at least a portion of said active feature along a first edge of said active feature; exposing said photosensitive layer to a second mask, said second mask exposing said first complementary feature.
Claim 3
Dependent Claim
54 words
The method as described in claim 1 wherein said portion of said active feature further comprises a second edge, said first mask comprising said first complementary feature proximate said first edge and a second complementary feature proximate said second edge, wherein said second mask exposes said first complementary feature and said second complementary feature.
Claim 4
Dependent Claim
17 words
The method as described in claim 2 wherein said active feature comprises a gate of a transistor.
Claim 5
Dependent Claim
32 words
The method as described in claim 3 wherein said first complementary feature and said second complementary feature are spaced an approximately equal distance from said first edge and said second edge, respectively.
Claim 6
Dependent Claim
21 words
The method as described in claim 4 wherein said exposure to said first mask is performed using a resolution enhancement technique.
Claim 7
Dependent Claim
26 words
The method as described in claim 5 wherein said resolution enhancement technique is selected from the group consisting of oblique illumination, pupil filtering, and phase shifting.
Claim 8
Dependent Claim
21 words
The method as described in claim 3 wherein said exposure to said first mask is performed using a resolution enhancement technique.
Claim 9
Dependent Claim
26 words
The method as described in claim 7 wherein said resolution enhancement technique is selected from the group consisting of oblique illumination, pupil filtering, and phase shifting.
Claim 10
Dependent Claim
32 words
The method as described in claim 2 wherein said first complementary feature and said second complementary feature are spaced an approximately equal distance from said first edge and said second edge, respectively.
Claim 11
Dependent Claim
21 words
The method as described in claim 9 wherein said exposure to said first mask is performed using a resolution enhancement technique.
Claim 12
Dependent Claim
26 words
The method as described in claim 10 wherein said resolution enhancement technique is selected from the group consisting of oblique illumination, pupil filtering, and phase shifting.
Claim 13
Dependent Claim
21 words
The method as described in claim 2 wherein said exposure to said first mask is performed using a resolution enhancement technique.
Claim 14
Dependent Claim
26 words
The method as described in claim 12 wherein said resolution enhancement technique is selected from the group consisting of oblique illumination, pupil filtering, and phase shifting.
Claim 15
Dependent Claim
17 words
The method as described in claim 1 wherein said active feature comprises a gate of a transistor.
Claim 16
Dependent Claim
21 words
The method as described in claim 14 wherein said exposure to said first mask is performed using a resolution enhancement technique.
Claim 17
Dependent Claim
26 words
The method as described in claim 15 wherein said resolution enhancement technique is selected from the group consisting of oblique illumination, pupil filtering, and phase shifting.
Claim 18
Dependent Claim
21 words
The method as described in claim 1 wherein said exposure to said first mask is performed using a resolution enhancement technique.
Claim 19
Dependent Claim
26 words
The method as described in claim 17 wherein said resolution enhancement technique is selected from the group consisting of oblique illumination, pupil filtering, and phase shifting.
Claim 20
Independent Claim
141 words
A method of forming a device layer comprising: providing a substrate having a first layer and a first photosensitive layer on said first layer; exposing said first photosensitive layer to a first mask, said first mask having an active feature and a first complementary feature proximate at least a portion of said active feature; developing said first photosensitive layer to form a patterned first photosensitive layer; removing said first layer in regions exposed by said patterned first photosensitive layer to form a patterned first layer; providing a second photosensitive layer over said patterned first layer; exposing said second photosensitive layer to a second mask; developing said second photosensitive layer to from a patterned second photosensitive layer, said patterned second photosensitive layer exposing said complementary feature and masking said active feature; and, removing said patterned first layer to remove said complementary feature.
Claim 21
Independent Claim
141 words
A method of forming a device layer comprising: providing a substrate having a first layer and a first photosensitive layer on said first layer; exposing said first photosensitive layer to a first mask, said first mask having an active feature and a first complementary feature proximate at least a portion of said active feature; developing said first photosensitive layer to form a patterned first photosensitive layer; removing said first layer in regions exposed by said patterned first photosensitive layer to form a patterned first layer; providing a second photosensitive layer over said patterned first layer; exposing said second photosensitive layer to a second mask; developing said second photosensitive layer to from a patterned second photosensitive layer, said patterned second photosensitive layer exposing said complementary feature and masking said active feature; and, removing said patterned first layer to remove said complementary feature.
Claim 22
Dependent Claim
59 words
The method as described in claim 19 wherein said portion of said active features comprises a first edge and a second edge, said first mask comprising said first complementary feature proximate said first edge and a second complementary feature proximate said second edge, wherein said patterned second photosensitive layer exposes said first complementary feature and said second complementary feature.
Claim 23
Dependent Claim
60 words
A mask set for forming a device layer comprising: a first mask having an active feature and a first complementary feature proximate at least a portion of said active feature along a first edge of said active feature; and, a second mask designed to form a patterned photosensitive layer which exposes said first complementary feature and masks said active feature.
Claim 24
Dependent Claim
60 words
A mask set for forming a device layer comprising: a first mask having an active feature and a first complementary feature proximate at least a portion of said active feature along a first edge of said active feature; and, a second mask designed to form a patterned photosensitive layer which exposes said first complementary feature and masks said active feature.
Claim 25
Dependent Claim
41 words
The mask set as described in claim 21, wherein said portion of said active feature further comprises a second edge, said first mask comprising said first complementary feature proximate said first edge and a second complementary feature proximate said second edge.
Claim 26
Dependent Claim
18 words
The mask set as described in claim 22 wherein said active feature comprises a gate of a transistor.
Claim 27
Dependent Claim
33 words
The mask set as described in claim 23 wherein said first complementary feature and said second complementary feature are spaced an approximately equal distance from said first edge and said second edge, respectively.
Claim 28
Dependent Claim
33 words
The mask set as described in claim 22 wherein said first complementary feature and said second complementary feature are spaced an approximately equal distance from said first edge and said second edge, respectively.
Claim 29
Dependent Claim
18 words
The mask set as described in claim 21 wherein said active feature comprises a gate of a transistor.
Claim 30
Dependent Claim
64 words
The mask set as described in claim 21 wherein said mask set is designed to pattern one or more positive photosensitive layers, wherein said first mask comprises first opaque regions corresponding to said active feature and said complementary feature, and wherein said second mask comprises a radiation transmitting region corresponding to said complementary feature and a second opaque region corresponding to said active feature.
Claim 31
Dependent Claim
67 words
The mask set as described in claim 21 wherein said mask set is designed to pattern a first and a second negative photosensitive layer, wherein said first mask comprises first radiation transmitting regions corresponding to said active feature and said complementary feature and wherein said second mask comprises a second radiation transmitting region corresponding to said active feature and an opaque region corresponding to said complementary feature.
Claim 32
Independent Claim
68 words
A method of patterning a feature in a photosensitive layer comprising the steps of: exposing said photosensitive layer to a first mask, said first mask having an active feature and one or more complementary feature, wherein said active feature and said one or more complementary feature form a periodic structure; exposing said photosensitive layer to a second mask, said second mask exposing said one or more complementary feature.
Claim 33
Independent Claim
68 words
A method of patterning a feature in a photosensitive layer comprising the steps of: exposing said photosensitive layer to a first mask, said first mask having an active feature and one or more complementary feature, wherein said active feature and said one or more complementary feature form a periodic structure; exposing said photosensitive layer to a second mask, said second mask exposing said one or more complementary feature.
Claim 34
Dependent Claim
57 words
The method as described in claim 29 wherein said portion of said active features comprises a first edge and a second edge, said first mask comprising a first complementary feature proximate said first edge and a second complementary feature proximate said second edge, wherein said second mask exposes said first complementary feature and said second complementary feature.
Claim 35
Dependent Claim
17 words
The method as described in claim 30 wherein said active feature comprises a gate of a transistor.
Claim 36
Dependent Claim
32 words
The method as described in claim 31 wherein said first complementary feature and said second complementary feature are spaced an approximately equal distance from said first edge and said second edge, respectively.
Claim 37
Dependent Claim
32 words
The method as described in claim 30 wherein said first complementary feature and said second complementary feature are spaced an approximately equal distance from said first edge and said second edge, respectively.
Claim 38
Dependent Claim
33 words
The mask set as described in claim 31 wherein said first complementary feature and said second complementary feature are spaced an approximately equal distance from said first edge and said second edge, respectively.
Claim 39
Dependent Claim
17 words
The method as described in claim 29 wherein said active feature comprises a gate of a transistor.
Claim 40
Dependent Claim
21 words
The method as described in claim 29 wherein said exposure to said first mask is performed using a resolution enhancement technique.
Claim 41
Dependent Claim
26 words
The method as described in claim 36 wherein said resolution enhancement technique is selected from the group consisting of oblique illumination, pupil filtering, and phase shifting.
Claim 42
Dependent Claim
60 words
A mask set for forming a device layer comprising: a first mask having an active feature and one or more complementary feature, wherein said active feature and said one or more complementary feature form a periodic structure; a second mask designed to form a patterned photosensitive layer that exposes said one or more complementary feature and masks said active feature.
Claim 43
Dependent Claim
60 words
A mask set for forming a device layer comprising: a first mask having an active feature and one or more complementary feature, wherein said active feature and said one or more complementary feature form a periodic structure; a second mask designed to form a patterned photosensitive layer that exposes said one or more complementary feature and masks said active feature.
Claim 44
Dependent Claim
44 words
The mask set as described in claim 38, wherein said portion of said active feature comprises a first edge and a second edge, said first mask comprising a first complementary feature proximate said first edge and a second complementary feature proximate said second edge.
Claim 45
Dependent Claim
18 words
The mask set as described in claim 39 wherein said active feature comprises a gate of a transistor.
Claim 46
Dependent Claim
33 words
The mask set as described in claim 39 wherein said first complementary feature and said second complementary feature are spaced an approximately equal distance from said first edge and said second edge, respectively.
Claim 47
Dependent Claim
18 words
The mask set as described in claim 38 wherein said active feature comprises a gate of a transistor.
Claim 48
Dependent Claim
64 words
The mask set as described in claim 38 wherein said mask set is designed to pattern one or more positive photosensitive layers, wherein said first mask comprises first opaque regions corresponding to said active feature and said complementary feature, and wherein said second mask comprises a radiation transmitting region corresponding to said complementary feature and a second opaque region corresponding to said active feature.
Claim 49
Dependent Claim
67 words
The mask set as described in claim 38 wherein said mask set is designed to pattern a first and a second negative photosensitive layer, wherein said first mask comprises first radiation transmitting regions corresponding to said active feature and said complementary feature and wherein said second mask comprises a second radiation transmitting region corresponding to said active feature and an opaque region corresponding to said complementary feature.
References Cited (Backward Citations)
US5308741A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-06-12 | 1998-12-12 | 1999-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-06-12 | 2002-12-12 | 2003-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-06-12 | 2006-12-12 | 2007-06-13 | $7700.00 | Window Closed / Lapsed |