Patent US4892613A successfully refreshed from Google Patents.
US4892613A
Expired / Lapsed
US
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Process for etching light-shielding thin film
Assignee: Seiko Precision Inc
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Filing: 1988-12-27
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Granted: 1990-01-09
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Expires: 2008-12-27
Abstract
Abstract A light shielding thin film is provided on a light transmitting substrate, and the film is covered by a photoresist. The photoresist is exposed and developed to form a pattern, and the film is etched using the pattern as a mask. The pattern is then exposed through the substrate, using the film as a mask, the pattern then being developed to form a pattern of reduced size. The film is then etched using the reduced size pattern as a mask.
Inventors
- 👤 Noboru Motai
- 👤 Sakae Tanaka
- 👤 Yoshiaki Watanabe
- 👤 Katsuo Shirai
- 👤 Yaeko Suzuki
- 👤 Yoshihisa Ogiwara
- 👤 Kazunori Saito
- 👤 Keiko Shibuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:32
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/031; H10D30/0312; H10D30/0316; H10D30/0321; H10D30/60; H10D30/67; H10D30/6704; H10D30/6723; H10D64/00; H10D64/01; H10D64/013; H10P; H10P76/00; H10P76/20; H10P76/204; H10P76/2041
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
121 words
A process for etching a light-shielding thin film which comprises the steps of: applying a photoresist to a light-shielding thin film formed on a light-transmitting substrate; exposing the photoresist and then developing the exposed photoresist, thereby forming a photoresist pattern of desired shape; etching the light-shielding thin film by using the photoresist pattern as a mask, thereby forming a light-shielding thin film pattern matching the photoresist pattern; exposing the photoresist pattern through the reverse side of the light-transmitting substrate by using the light-shielding thin film pattern as a mask and then developing the exposed photoresist pattern, thereby reducing the size of the photoresist pattern; and etching the light-shielding thin film pattern by using the reduced size photoresist pattern as a mask.
Claim 2
Dependent Claim
121 words
A process for etching a light-shielding thin film which comprises the steps of: applying a photoresist to a light-shielding thin film formed on a light-transmitting substrate; exposing the photoresist and then developing the exposed photoresist, thereby forming a photoresist pattern of desired shape; etching the light-shielding thin film by using the photoresist pattern as a mask, thereby forming a light-shielding thin film pattern matching the photoresist pattern; exposing the photoresist pattern through the reverse side of the light-transmitting substrate by using the light-shielding thin film pattern as a mask and then developing the exposed photoresist pattern, thereby reducing the size of the photoresist pattern; and etching the light-shielding thin film pattern by using the reduced size photoresist pattern as a mask.
Claim 3
Dependent Claim
24 words
A process for etching a light-shielding thin film as claimed in claim 1 comprising using a metal thin film as the light-shielding thin film.
Claim 4
Dependent Claim
24 words
A process for etching a light-shielding thin film as claimed in claim 1 comprising using a semiconductor thin film as the light-shielding thin film.
Claim 5
Dependent Claim
24 words
A process for etching a light-shielding thin film as claimed in claim 3 comprising using a silicon thin film as the semiconductor thin film.
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) | 1993-01-08 | 1993-07-10 | 1994-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-08 | 1997-07-10 | 1998-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-08 | 2001-07-10 | 2002-01-09 | $7700.00 | Window Closed / Lapsed |