US4504574A
Expired / Lapsed
US
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Method of forming a resist mask resistant to plasma etching
Assignee: US Philips Corp
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Filing: 1983-05-20
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Granted: 1985-03-12
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Expires: 2003-05-20
Abstract
Abstract A mask which is resistant to a plasma etching treatment is formed by lithographically patterning a radiation sensitive film present on a substrate. The etch resistance of the mask is enhanced by exposure to a carbon monoxide plasma which forms a region with an enhanced etch resistance over the surface of the patterned film. This method may be used, for example, to manufacture a photomask using a chromium coated glass substrate, or during the manufacture of semiconductor devices on a semiconductor wafer substrate.
Inventors
- 👤 Joseph Meyer
- 👤 David J. Vinton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:25
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/26; G03F7/40
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
53 words
A method of forming a mask resistant to plasma etching comprising the steps of forming a lithographically patterned layer of radiation sensitive resist on a substrate, and exposing said patterned resist to a carbon monoxide plasma to form on the surface of said patterned resist a region having enhanced resistance to plasma etching.
Claim 2
Independent Claim
53 words
A method of forming a mask resistant to plasma etching comprising the steps of forming a lithographically patterned layer of radiation sensitive resist on a substrate, and exposing said patterned resist to a carbon monoxide plasma to form on the surface of said patterned resist a region having enhanced resistance to plasma etching.
Claim 3
Dependent Claim
14 words
A method according to claim 1, wherein said radiation sensitive resist is positive acting.
Claim 4
Dependent Claim
18 words
A method according to claim 1, wherein said radiation sensitive resist is a cross-linked positive acting co-polymer resist.
Claim 5
Dependent Claim
21 words
A method according to claim 3, wherein said co-polymer resist includes a mixture of poly-(methyl methacrylate-co-methacrylic acid) and poly-(methyl methacrylate-co-methacryloyl chloride).
Claim 6
Dependent Claim
17 words
A method according to claim 1, wherein said resist has a thickness of less than 0.4 micrometers.
Claim 7
Dependent Claim
22 words
A method according to claim 1, wherein said patterned resist is formed on a chromium layer on the surface of said substrate.
Claim 8
Dependent Claim
18 words
A method according to claim 6, wherein said substrate is an alumino-silicate substrate or a synthetic quartz substrate.
Claim 9
Dependent Claim
28 words
A method according to claim 1, wherein said carbon monoxide plasma is formed at a pressure of 0.4 Torr, and a power of 100 W for 5 minutes.
Claim 10
Dependent Claim
13 words
A method according to claim 1, wherein said substrate is a semiconductor material.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-03-11 | 1988-09-10 | 1989-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-03-11 | 1992-09-10 | 1993-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-03-11 | 1996-09-10 | 1997-03-12 | $7700.00 | Window Closed / Lapsed |