Patent US4426439A successfully refreshed from Google Patents.
US4426439A
Expired / Lapsed
US
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Method and apparatus for processing negative photoresist
Assignee: Fujitsu Ltd
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Filing: 1981-12-11
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Granted: 1984-01-17
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Expires: 2001-12-11
Abstract
Abstract A negative photoresist emulsion, wherein after a film of negative photoresist emulsion on a substrate has been exposed for pattern writing in vacuum to charged particle beams or soft X-ray beams, the film-coated substrate is transferred to, and kept in, a chamber filled with non-oxidizing gas, and then the substrate is removed to the outside atmosphere. By this method, a curing effect of the photoresist film is prevented, enabling formation of fine patterns with precision. An apparatus for carrying out the above method, has a gas chamber filled with non-oxidizing gas connected to an exposure chamber, and the substrate, after such exposure, is kept in an atmosphere of non-oxidizing gas in the gas chamber before being removed to the outside atmosphere. In either the above-method or apparatus, the concentration of oxygen in the non-oxidizing gas must be less than 5%, preferably less than 1%.
Inventors
- 👤 Koichi Kobayashi
- 👤 Kenichi Kawashima
- 👤 Shuzo Oshio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:57
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/26; G03F7/38; G03F7/20; Y; Y10; Y10S; Y10S430/00; Y10S430/167; Y10S430/168
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
81 words
A method of exposure processing comprising the steps of: exposing for pattern writing in vacuum a film of negative photoresist emulsion to charged particle beams or soft X-ray beams, transferring said photoresist film to, and keeping the film in, a chamber of non-oxidizing gas atmosphere containing up to 5% volume oxygen for a period of time sufficient to inhibit postpolymerization or curing of the photoresist, and thereafter removing the photoresist film to the outside atmosphere from said atmosphere of non-oxidizing gas.
Claim 2
Independent Claim
81 words
A method of exposure processing comprising the steps of: exposing for pattern writing in vacuum a film of negative photoresist emulsion to charged particle beams or soft X-ray beams, transferring said photoresist film to, and keeping the film in, a chamber of non-oxidizing gas atmosphere containing up to 5% volume oxygen for a period of time sufficient to inhibit postpolymerization or curing of the photoresist, and thereafter removing the photoresist film to the outside atmosphere from said atmosphere of non-oxidizing gas.
Claim 3
Dependent Claim
20 words
A method of claim 1 wherein the oxygen contained in said non-oxidizing gas is less than one percent in volume.
Claim 4
Dependent Claim
92 words
A method of claim 1 which comprises the steps of: irradiating charged particle beams or soft X-ray beams onto a substrate coated with negative photoresist emulsion for pattern writing exposure in vacuum, transferring said substrate in vacuum to a gas chamber connected to a chamber where exposure is carried out, shutting off said exposure chamber and said gas chamber from each other, introducing non-oxidizing gas into said chamber to keep said substrate in an atmosphere of non-oxidizing gas, and removing said substrate from the atmosphere of non-oxidizing gas to the outside atmosphere.
Claim 5
Dependent Claim
105 words
A method of claim 1 comprising the steps of: irradiating charged particle beams or soft X-ray beams onto a substrate coated with a film of negative photoresist emulsion for pattern writing exposure, transferring said substrate in vacuum to a sub-chamber connected to a chamber where exposure is carried out, shutting off said exposure chamber and said sub-chamber from each other, introducing non-oxidizing gas into said sub-chamber to keep said substrate in an atmosphere of non-oxidizing gas, transferring said substrate in the atmosphere of non-oxidizing gas to a gas chamber connected to said sub-chamber, and removing said substrate from said gas chamber to the outside atmosphere.
Claim 6
Independent Claim
117 words
A method of exposure processing, comprising the steps of: (a) placing a semiconductor substrate having thereon a film of a negative photoresist in a stage chamber; (b) exhausting air from the stage chamber to induce a vacuum condition in the stage chamber; (c) exposing the substrate to electron beams for pattern writing in vacuum; (d) stopping exhaustion of air from the stage chamber; (e) introducing nitrogen gas into the chamber; (f) transferring the substrate to a sub-chamber filled with nitrogen gas containing up to 5% volume oxygen; (g) holding the substrate in the sub-chamber for a certain length of time to inhibit post-polymerization or curing of the photoresist; and (h) removing the substrate to the outside air.
Claim 7
Independent Claim
117 words
A method of exposure processing, comprising the steps of: (a) placing a semiconductor substrate having thereon a film of a negative photoresist in a stage chamber; (b) exhausting air from the stage chamber to induce a vacuum condition in the stage chamber; (c) exposing the substrate to electron beams for pattern writing in vacuum; (d) stopping exhaustion of air from the stage chamber; (e) introducing nitrogen gas into the chamber; (f) transferring the substrate to a sub-chamber filled with nitrogen gas containing up to 5% volume oxygen; (g) holding the substrate in the sub-chamber for a certain length of time to inhibit post-polymerization or curing of the photoresist; and (h) removing the substrate to the outside air.
Claim 8
Dependent Claim
15 words
A method of exposure processing according to claim 1 wherein the negative photoresist is polydiarylorthophtalate.
Claim 9
Dependent Claim
15 words
A method according to claim 5, wherein the negative photoresist film is made of polydiarylorthophtalate.
Claim 10
Dependent Claim
20 words
A method of claim 1, wherein the oxygen contained in said non-oxidizing gas is less than five percent in volume.
Claim 11
Dependent Claim
33 words
A method of exposure processing according to claim 1, wherein the non-oxidizing gas is nitrogen, argon, helium or a mixture of these, and wherein the non-oxidizing gas contains up to 5% volume oxygen.
Claim 12
Dependent Claim
16 words
A method of exposure processing according to claim 1, wherein the negative photoresist is polyglycidylmetha acrylate.
Claim 13
Dependent Claim
16 words
A method according to claim 5, wherein the negative photoresist film is made of polyglycidylmetha acrylate.
Claim 14
Dependent Claim
22 words
A method of exposure processing according to claim 5, wherein the certain length of time is from 30 minutes to one hour.
Claim 15
Dependent Claim
21 words
A method of exposure processing according to claim 5, wherein the certain length of time is 3 minutes to one hour.
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) | 1987-01-16 | 1987-07-18 | 1988-01-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-16 | 1991-07-18 | 1992-01-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-16 | 1995-07-18 | 1996-01-17 | $7700.00 | Window Closed / Lapsed |