Patent US4985319A successfully refreshed from Google Patents.
US4985319A
Expired / Lapsed
US
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Process for manufacturing a photomask
Assignee: Mitsubishi Electric Corp
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Filing: 1989-10-23
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Granted: 1991-01-15
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Expires: 2009-10-23
Abstract
Abstract A photomask manufacturing process including a step of forming metal silicide film on a transparent silica glass substrate. A resist is applied onto the metal silicide film and then a patterning mask is provided by light or electron beam, followed by developing step. Exposed portions of the metal silicide film is etched away using a dry etching process.
Inventors
- 👤 Yaichiro Watakabe
- 👤 Tatsuo Okamoto
- 👤 Shuichi Matsuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:39
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/54
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
107 words
A process for manufacturing a photomask comprising the steps of: preparing a substantially transparent glass substrate; forming a metal silicide film opaque to visible light and having a thickness of about 1000 Å on a transparent glass substrate, said metal silicide film being selected from the group consisting of one of a silicide film of molybdenum and tungsten; applying a resist on said metal silicide film; providing a mask pattern of said resist by light or electron beam; etching away at least an exposed portion of said metal silicide film by means of a dry etching process at an etching rate of about 500-1000 Å per minute.
Claim 2
Dependent Claim
107 words
A process for manufacturing a photomask comprising the steps of: preparing a substantially transparent glass substrate; forming a metal silicide film opaque to visible light and having a thickness of about 1000 Å on a transparent glass substrate, said metal silicide film being selected from the group consisting of one of a silicide film of molybdenum and tungsten; applying a resist on said metal silicide film; providing a mask pattern of said resist by light or electron beam; etching away at least an exposed portion of said metal silicide film by means of a dry etching process at an etching rate of about 500-1000 Å per minute.
Claim 3
Dependent Claim
23 words
A process according to claim 1, wherein said etching is performed using a mixture of fluorine gas and oxygen as the etching gas.
References Cited (Backward Citations)
US4876164A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-01-14 | 1994-07-16 | 1995-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-14 | 1998-07-16 | 1999-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-14 | 2002-07-16 | 2003-01-15 | $7700.00 | Window Closed / Lapsed |