Patent US4678714A successfully refreshed from Google Patents.
US4678714A
Expired / Lapsed
US
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Photomask material
Assignee: Mitsubishi Electric Corp
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Filing: 1986-01-15
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Granted: 1987-07-07
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Expires: 2006-01-15
Abstract
Abstract A photomask material comprising a transparent glass substrate and a metal silicide film formed on the transparent glass substrate, the rate of a silicon and a metal in the metal silicide film being continuously varied so as to increase the amount of metal toward an upper surface of the metal silicide film.
Inventors
- 👤 Yaichiro Watakabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:42
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/54; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12611
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
78 words
a photomask material comprising a transparent glass substrate and a metal silicide film formed on said transparent glass substrate, the metal silicide film having a lower surface contacting the substrate and an upper surface opposed to the lower surface, the improvement wherein the rate of deposition of silicon in relation to metal contained in said metal silicide film is continuously varied so as to increase the amount of metal toward the upper surface of the metal silicide film.
Claim 2
Dependent Claim
78 words
a photomask material comprising a transparent glass substrate and a metal silicide film formed on said transparent glass substrate, the metal silicide film having a lower surface contacting the substrate and an upper surface opposed to the lower surface, the improvement wherein the rate of deposition of silicon in relation to metal contained in said metal silicide film is continuously varied so as to increase the amount of metal toward the upper surface of the metal silicide film.
Claim 3
Dependent Claim
17 words
A photomask material in accordance with claim 1, wherein said transparent glass substrate is a silica glass.
Claim 4
Dependent Claim
30 words
A photomask material in accordance with claim 1, wherein said deposition rate of silicon in relation to metal contained in the metal silicide film is varied in a linear manner.
References Cited (Backward Citations)
JPS5642183A
Cited
JPS5642176A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-07-06 | 1991-01-05 | 1991-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-06 | 1995-01-05 | 1995-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-06 | 1999-01-05 | 1999-07-07 | $7700.00 | Window Closed / Lapsed |