Patent US4720442A successfully refreshed from Google Patents.
US4720442A
Expired / Lapsed
US
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Photomask blank and photomask
Assignee: AGC Inc
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Filing: 1986-05-27
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Granted: 1988-01-19
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Expires: 2006-05-27
Abstract
Abstract A photomask blank comprising a transparent substrate and at least two layers including a masking layer and an antireflection layer, formed thereon, wherein said masking layer is a chromium masking layer containing more than 25% by atomic ratio of nitrogen, and said antireflection layer is a chromium oxide antireflection layer containing more than 25% by atomic ratio of nitrogen.
Inventors
- 👤 Norihiko Shinkai
- 👤 Takeshi Haranoh
- 👤 Junetsu Kanazawa
- 👤 Takashi Hatano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:43
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/38; G03F1/46; G03F1/50; G03F1/54
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
71 words
A photomask blank comprising a transparent substrate and at least two layers including a masking layer and an antireflection layer, formed thereon, wherein said masking layer is a chromium masking layer containing from more than 25% to not more than 50% by atomic ratio of nitrogen, and said antireflection layer is a chromium oxide antireflection layer containing from more than 25% to not more than 40% by atomic ratio of nitrogen.
Claim 2
Dependent Claim
71 words
A photomask blank comprising a transparent substrate and at least two layers including a masking layer and an antireflection layer, formed thereon, wherein said masking layer is a chromium masking layer containing from more than 25% to not more than 50% by atomic ratio of nitrogen, and said antireflection layer is a chromium oxide antireflection layer containing from more than 25% to not more than 40% by atomic ratio of nitrogen.
Claim 3
Dependent Claim
16 words
The photomask blank according to claim 1, wherein the chromium masking layer contains boron or carbon.
Claim 4
Dependent Claim
32 words
The photomask blank according to claim 1, wherein the chromium masking layer contains from 1 to 20% by atomic ratio of boron, or from 5 to 30% by atomic ratio of carbon.
Claim 5
Dependent Claim
35 words
The photomask blank according to claim 2, wherein a chromium layer containing more than 25% by atomic ratio of nitrogen is formed on the transparent substrate, as an under layer beneath the chromium masking layer.
Claim 6
Dependent Claim
20 words
The photomask blank according to claim 4, wherein the under layer has a thickness of from 50 to 300 Å.
Claim 7
Dependent Claim
34 words
The photomask blank according to claim 1, wherein the antireflection layer is formed on the transparent substrate and beneath the chromium masking layer, and another antireflection layer is formed on the chromium masking layer.
Claim 8
Dependent Claim
72 words
A photomask comprising a transparent substrate and at least two patternized layers including a patternized masking layer and a patternized antireflection layer, formed thereon, wherein said masking layer is a chromium masking layer containing from more than 25% to not more than 50% by atomic ratio of nitrogen, and said antireflection layer is a chromium oxide antireflection layer containing from more than 25% to not more than 40% atomic ratio of nitrogen.
Claim 9
Dependent Claim
72 words
A photomask comprising a transparent substrate and at least two patternized layers including a patternized masking layer and a patternized antireflection layer, formed thereon, wherein said masking layer is a chromium masking layer containing from more than 25% to not more than 50% by atomic ratio of nitrogen, and said antireflection layer is a chromium oxide antireflection layer containing from more than 25% to not more than 40% atomic ratio of nitrogen.
Claim 10
Dependent Claim
15 words
The photomask according to claim 7, wherein the chromium masking layer contains boron or carbon.
Claim 11
Dependent Claim
31 words
The photomask according to claim 7, wherein the chromium masking layer contains from 1 to 20% by atomic ratio of boron, or from 5 to 30% by atomic ratio of carbon.
Claim 12
Dependent Claim
34 words
The photomask according to claim 8, wherein a chromium layer containing more than 25% by atomic ratio of nitrogen is formed on the transparent substrate, as an under layer beneath the chromium masking layer.
Claim 13
Dependent Claim
19 words
The photomask according to claim 10, wherein the under layer has a thickness of from 50 to 300 Å.
Claim 14
Dependent Claim
33 words
The photomask according to claim 7, wherein the antireflection layer is formed on the transparent substrate and beneath the chromium masking layer, and another antireflection layer is formed on the chromium masking layer.
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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) | 1991-01-18 | 1991-07-20 | 1992-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-18 | 1995-07-20 | 1996-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-18 | 1999-07-20 | 2000-01-19 | $7700.00 | Window Closed / Lapsed |