US4876164A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for manufacturing a photomask
Assignee: Mitsubishi Electric Corp
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Filing: 1987-07-17
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Granted: 1989-10-24
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Expires: 2007-07-17
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
2026-11-01 02:06
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/54
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
91 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 on said 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 by light or electron beam, followed by a developing process; etching away at least an exposed portion of said metal silicide film by means of a dry etching process.
Claim 2
Dependent Claim
91 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 on said 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 by light or electron beam, followed by a developing process; etching away at least an exposed portion of said metal silicide film by means of a dry etching process.
Claim 3
Dependent Claim
21 words
A process for manufacturing a photomask in accordance with claim 1, wherein said transparent glass substrate is a silica glass substrate.
Claim 4
Dependent Claim
26 words
A process for manufacturing a photomask in accordance with claim 1, wherein said metal silicide film is a thin film of about 1000 Å in thickness.
Claim 5
Dependent Claim
113 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 being a thickness of approximately 4000-6000 Å, 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 dryetching process at an etching rate of about 500-1000 Å per minute.
Claim 6
Dependent Claim
113 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 being a thickness of approximately 4000-6000 Å, 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 dryetching process at an etching rate of about 500-1000 Å per minute.
Claim 7
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.
Claim 8
Dependent Claim
23 words
A process according to claim 3, wherein said etching is performed using a mixture of fluorine gas and oxygen as the etching gas.
Claim 9
Dependent Claim
23 words
A process according to claim 4, wherein said etching is performed using a mixture of fluorine gas and oxygen as the etching gas.
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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) | 1992-10-23 | 1993-04-24 | 1993-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-23 | 1997-04-24 | 1997-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-23 | 2001-04-24 | 2001-10-24 | $7700.00 | Window Closed / Lapsed |