Patent US4581316A successfully refreshed from Google Patents.
US4581316A
Expired / Lapsed
US
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Method of forming resist patterns in negative photoresist layer using false pattern
Assignee: Fujitsu Ltd
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Filing: 1985-02-19
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Granted: 1986-04-08
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Expires: 2005-02-19
Abstract
Abstract In a method of forming very minute real window patterns to a negative photoresist film that are required in the manufacture of highly packed semiconductor devices, false unexposed patterns are formed in the proximity of the minute real unexposed patterns. The false patterns have a width that, upon a single exposure of the negative photoresist film to ultraviolet light or other energy beam, the photoresist film portion immediately below the false patterns are unexposed but a photoresist portion under the unexposed portion is exposed to light by reason of light diffraction or light circling around under the false pattern. As a result, the false patterns in the photoresist film substantially disappear after development of the photoresist. The partially removed false patterns serve to negate swelling of the photoresist at the time of development and prevent obliteration of the real window patterns or formation of burr-like parts where the real window patterns are to be formed.
Inventors
- 👤 Kazuaki Yamanouchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:50
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70425; G03F7/70433; G03F7/20; G03F7/2002; G03F7/26; G03F7/30; H; H10; H10P; H10P95/00; Y; Y10; Y10S; Y10S430/00; Y10S430/153; Y10S430/167; Y10S430/168
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
152 words
A method for forming an opening having a width of approximately 3 μm or less to a negative photoresist film comprising the steps of: performing a single partial exposure to a negative photoresist film to form first and second unexposed portions of said photoresist film, said first unexposed portion corresponding to said opening and said second unexposed portion being disposed proximately to said first portion, and developing said photoresist film to selectively remove said first and second unexposed portions to form said opening at said first unexposed portion of said photoresist film, said second unexposed portion being separated from and parallel with said first unexposed portion, having a width minute enough to prevent formation of a through-hole thereat and being disposed closely enough to said first unexposed portion to prevent said opening from being obliterated in the developing step by absorbing swelling of the negative photoresist film at said second unexposed portion.
Claim 2
Independent Claim
152 words
A method for forming an opening having a width of approximately 3 μm or less to a negative photoresist film comprising the steps of: performing a single partial exposure to a negative photoresist film to form first and second unexposed portions of said photoresist film, said first unexposed portion corresponding to said opening and said second unexposed portion being disposed proximately to said first portion, and developing said photoresist film to selectively remove said first and second unexposed portions to form said opening at said first unexposed portion of said photoresist film, said second unexposed portion being separated from and parallel with said first unexposed portion, having a width minute enough to prevent formation of a through-hole thereat and being disposed closely enough to said first unexposed portion to prevent said opening from being obliterated in the developing step by absorbing swelling of the negative photoresist film at said second unexposed portion.
Claim 3
Dependent Claim
18 words
The method of claim 1 further comprising the step of rinsing said resist film after said developing step.
Claim 4
Dependent Claim
44 words
The method of claim 1 wherein the first and second portions of said resist film are formed in said exposing step at a distance d, between the first portion having a width w and the second portion, in the range of w to 5w.
Claim 5
Dependent Claim
19 words
The method of claim 1 wherein said resist film is partially exposed to ultraviolet light through a photographic mask.
Claim 6
Dependent Claim
23 words
The method of claim 1, wherein the distance between said first and second portions is in the range of 2 to 15 μm.
Claim 7
Dependent Claim
20 words
The method of claim 5 wherein said photoresist film has a thickness in the range of 8,000 to 10,000 Å.
Claim 8
Dependent Claim
18 words
The method of claim 5 wherein said first portion has a width of approximately 3 μm or less.
Claim 9
Dependent Claim
18 words
The method of claim 7 wherein said second portion has a width of approximately 1 μm or less.
Claim 10
Dependent Claim
20 words
The method of claim 8 wherein said photoresist film has a thickness in the range of 8,000 to 10,000 Å.
Claim 11
Dependent Claim
27 words
The method of claim 4 wherein said photographic mask has false patterns and real patterns to respectively form said first and second portions of said photoresist film.
Claim 12
Dependent Claim
50 words
The method of claim 10 wherein said false patterns have a width determined to allow light to partially circle beneath said false patterns during the exposing step for forming said second unexposed portions immediately below said false patterns and exposed areas of said photoresist film beneath said second unexposed portions.
Claim 13
Dependent Claim
25 words
The method of claim 1 wherein said photoresist film is a negative X-ray photoresist film and is partially exposed to an X-ray through a mask.
Claim 14
Dependent Claim
25 words
The method of claim 1 wherein said photoresist film is an electron beam resist and is partially exposed to an electron beam through a mask.
Claim 15
Dependent Claim
31 words
The method of claim 1 wherein said required opening to be formed in said resist film is not in proximity to another required opening to be formed in said photoresist film.
Claim 16
Independent Claim
213 words
A method for forming a required opening to a negative photoresist film in the manufacture of an integrated semiconductor device comprising the steps of: (a) performing a single partial exposure to a negative photoresist film having a thickness in the range of 8,000 to 10,000 A using a mask having false and real patterns in proximity to one another to form first and second unexposed portions, said first unexposed portion formed having a width of approximately 3 μm or less under said real pattern to correspond to said required opening and said second unexposed portion formed having a width of approximately 1 μm or less under said false pattern at a distance to said first unexposed portion of 2 to 15 μm; and (b) developing said photoresist film to selectively remove said first and second unexposed portions, said first portion being removed to form said required opening of a width of approximately 3 μm or less in said film and said second portion having said width minute enough to prevent formation of a hole through said photoresist film and being disposed at said distance to said first unexposed portion to prevent said opening from being obliterated in the developing step by absorbing swelling of the negative photoresist film at said second unexposed portion.
Claim 17
Independent Claim
213 words
A method for forming a required opening to a negative photoresist film in the manufacture of an integrated semiconductor device comprising the steps of: (a) performing a single partial exposure to a negative photoresist film having a thickness in the range of 8,000 to 10,000 A using a mask having false and real patterns in proximity to one another to form first and second unexposed portions, said first unexposed portion formed having a width of approximately 3 μm or less under said real pattern to correspond to said required opening and said second unexposed portion formed having a width of approximately 1 μm or less under said false pattern at a distance to said first unexposed portion of 2 to 15 μm; and (b) developing said photoresist film to selectively remove said first and second unexposed portions, said first portion being removed to form said required opening of a width of approximately 3 μm or less in said film and said second portion having said width minute enough to prevent formation of a hole through said photoresist film and being disposed at said distance to said first unexposed portion to prevent said opening from being obliterated in the developing step by absorbing swelling of the negative photoresist film at said second unexposed portion.
Claim 18
Dependent Claim
31 words
The method of claim 15 wherein said required opening to be formed in said photoresist film is not in proximity to another required opening to be formed in said photoresist film.
Claim 19
Dependent Claim
50 words
The method of claim 15 wherein said false patterns have a width determined to allow light to partially circle beneath said false patterns during the exposing step for forming said second unexposed portions immediately below said false patterns and exposed areas of said photoresist film beneath said second unexposed portions.
Claim 20
Dependent Claim
44 words
The method of claim 15 wherein the first and second portions of said photoresist film are formed in said exposing step at a distance d, between the first portion having a width w and the second portion, in the range of w to 5w.
Claim 21
Dependent Claim
19 words
The method of claim 15 wherein said photoresist film is partially exposed to ultraviolet light through a photographic mask.
Claim 22
Dependent Claim
25 words
The method of claim 15 wherein said photoresist film is a negative X-ray photoresist film and is partially exposed to an X-ray through a mask.
Claim 23
Dependent Claim
26 words
The method of claim 15 wherein said photoresist film is an electron beam photoresist film and is partially exposed to an electron beam through a mask.
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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) | 1989-04-07 | 1989-10-07 | 1990-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-07 | 1993-10-07 | 1994-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-07 | 1997-10-07 | 1998-04-08 | $7700.00 | Window Closed / Lapsed |