Patent US5139925A successfully refreshed from Google Patents.
US5139925A
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Surface barrier silylation of novolak film without photoactive additive patterned with 193 nm excimer laser
Assignee: Massachusetts Institute of Technology
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Filing: 1989-10-18
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Granted: 1992-08-18
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Expires: 2009-10-18
Abstract
Abstract A resist exposed to patterned radiation at 193 nm forms a highly crosslinked barrier layer in the exposed regions of the resist surface. The complementary surface regions are silylated in a silicon-containing reagent, and the exposed regions are readily removed by a oxygen RIE plasma. The laser exposure is a reciprocal process allowing precise control. Pattern definition is enhanced by limiting the exposure and the silylation to the surface of the resist.
Inventors
- 👤 Mark A. Hartney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:20
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/26; G03F7/265; Y; Y10; Y10S; Y10S430/00; Y10S430/146
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
136 words
A method of selectively silylating a film to form an etch barrier, such method comprising the steps of exposing a novolac film without photoactive additives to a patterned dose of 193 nm excimer laser ultraviolet radiation in an amount effective to crosslink the film only at its surface in exposed regions, and after exposure placing said film surface in a silylating reagent under conditions to selectively silylate surface regions of the film complementary to the exposed regions, said excimer laser being controlled to provide a fluence below the ablation threshold of the film and a total dose effective to crosslink only an outer surface portion in said exposed regions without introducing thermal effects, whereby the resist functions as a positive silylation resist of high contrast and resolution when silylated under a minimal set of silylation conditions.
Claim 2
Independent Claim
136 words
A method of selectively silylating a film to form an etch barrier, such method comprising the steps of exposing a novolac film without photoactive additives to a patterned dose of 193 nm excimer laser ultraviolet radiation in an amount effective to crosslink the film only at its surface in exposed regions, and after exposure placing said film surface in a silylating reagent under conditions to selectively silylate surface regions of the film complementary to the exposed regions, said excimer laser being controlled to provide a fluence below the ablation threshold of the film and a total dose effective to crosslink only an outer surface portion in said exposed regions without introducing thermal effects, whereby the resist functions as a positive silylation resist of high contrast and resolution when silylated under a minimal set of silylation conditions.
Claim 3
Dependent Claim
22 words
The method of claim 1, further comprising the step of etching the exposed silylated resist film in an oxygen RIE plasma etch.
Claim 4
Dependent Claim
17 words
The method of claim 2, further comprising the step of providing a halogen-containing pre- or post- etch.
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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) | 1995-08-18 | 1996-02-17 | 1996-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-18 | 2000-02-17 | 2000-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-18 | 2004-02-17 | 2004-08-18 | $7700.00 | Window Closed / Lapsed |