US5554484A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gamma radiation sensitive resist materials for semiconductor lithography
Assignee: LSI Corp
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Filing: 1994-12-19
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Granted: 1996-09-10
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Expires: 2014-12-19
Abstract
Abstract Fine, sub-micron line features and patterns are created in a radiation sensitive resist layer on a semiconductor wafer by a beam of short wavelength gamma rays. The resist layer includes photoresist which is substantially chemically inactive in response to the gamma rays. The photoresist is either doped or covered with a material that absorbs gamma rays and in response emits secondary radiation of a different wavelength, preferably photons, that is actinic with respect to the photoresist. The resist layer enables using radiation sources having better resolving ability than conventional photolithographic sources to perform near-field and direct-write lithography.
Inventors
- 👤 Michael D. Rostoker
- 👤 Nicholas F. Pasch
- 👤 Joe Zelayeta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:14
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/09; G02B27/0938; G02B27/0994; G02B17/00; G02B26/00; G02B26/02; G03; G03F; G03F7/00; G03F7/70; G03F7/70008; G03F7/70058; G03F7/702; G03F7/70375; G21; G21K; G21K1/00; G21K1/02; G21K1/04; G02F; G02F1/00; G02F1/29; G02F1/33; H; H10; H10P; H10P76/00; H10P76/20; H10P76/204; H10P76/2041; H10P76/2042; Y; Y10; Y10S; Y10S430/00; Y10S430/1053; Y10S430/1055; Y10S430/106; Y10S430/107; Y10S430/108
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
83 words
A radiation sensitive resist material for application on a surface of a semiconductor wafer, comprising: a base resist material having a high cross-section and absorptivity to, and being chemically sensitive to, photons; and a doping material having a high cross-section to gamma rays, being responsive to incident gamma rays to emit photons, and being provided in a concentration selected so that the doping material, in response to imaging gamma rays, emits a sufficient quantity of photons to chemically convert the base resist material.
Claim 2
Dependent Claim
83 words
A radiation sensitive resist material for application on a surface of a semiconductor wafer, comprising: a base resist material having a high cross-section and absorptivity to, and being chemically sensitive to, photons; and a doping material having a high cross-section to gamma rays, being responsive to incident gamma rays to emit photons, and being provided in a concentration selected so that the doping material, in response to imaging gamma rays, emits a sufficient quantity of photons to chemically convert the base resist material.
Claim 3
Dependent Claim
21 words
The radiation sensitive resist material according to claim 1 in which the doping material is doped into the base resist material.
Claim 4
Dependent Claim
38 words
The radiation sensitive resist material according to claim 1 in which the doping material and the base resist material are formed as separate base resist material and doping material layers respectively over the surface of the semiconductor wafer.
Claim 5
Dependent Claim
37 words
The radiation sensitive resist material according to claim 3 in which the base resist material layer is formed over the surface of the substrate and the doping material layer is formed over the base resist material layer.
Claim 6
Dependent Claim
20 words
The radiation sensitive resist material according to claim 1 in which the base resist material is an organic resist material.
Claim 7
Dependent Claim
17 words
The radiation sensitive resist material according to claim 5 in which the base resist material includes polystyrene.
Claim 8
Dependent Claim
17 words
The radiation sensitive resist material according to claim 5 in which the base resist material includes phenolformaldehyde.
Claim 9
Dependent Claim
17 words
The radiation sensitive resist material according to claim 5 in which the base resist material includes polyurethane.
Claim 10
Dependent Claim
18 words
The radiation sensitive resist material according to claim 1 in which the doping material is an inorganic material.
Claim 11
Dependent Claim
33 words
The radiation sensitive resist material according to claim 9 in which the doping material is selected from the group consisting of bromine, chromium, tantalum, gold, platinum, palladium, lead, barium, boron, aluminum and magnesium.
Claim 12
Dependent Claim
20 words
The radiation sensitive resist material according to claim 9 in which the base resist material is an organic resist material.
Claim 13
Dependent Claim
17 words
The radiation sensitive resist material according to claim 9 in which the base resist material includes polystyrene.
Claim 14
Dependent Claim
17 words
The radiation sensitive resist material according to claim 9 in which the base resist material includes phenolformaldehyde.
Claim 15
Dependent Claim
17 words
The radiation sensitive resist material according to claim 9 in which the base resist material includes polyurethane.
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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) | 1999-09-10 | 2000-03-11 | 2000-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-09-10 | 2004-03-11 | 2004-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-09-10 | 2008-03-11 | 2008-09-10 | $7700.00 | Window Closed / Lapsed |