Patent US4674174A successfully refreshed from Google Patents.
US4674174A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for forming a conductor pattern using lift-off
Assignee: Toshiba Corp
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Filing: 1985-10-11
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Granted: 1987-06-23
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Expires: 2005-10-11
Abstract
Abstract Disclosed is a method for forming a conductor pattern which comprises the steps of forming a conductive layer on a semiconductor substrate, forming a photoresist film on the conductive layer, removing that portion of the photoresist film located on a conductor pattern forming region of the conductive layer, forming a first masking metal film over the whole surface of the resultant structure, removing the photoresist film along with that portion of the first masking metal film formed thereon so that a portion of the first masking film remains on the conductor pattern forming region of the conductive layer to form a first masking metal pattern, and selectively removing the conductive layer by anisotropic etching to form the conductor pattern. Since the selective removal of the conductor layer is accomplished by the use of the metal pattern as a mask, it is possible to form a much finer conductor pattern than is obtained with the use of the photoresist pattern as the mask.
Inventors
- 👤 Yoshihiro Kishita
- 👤 Motoki Furukawa
- 👤 Tatsuro Mitani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:03
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/061; H10D30/0612; H10D30/0616; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/268; H10P76/00; H10P76/20; H10P76/202
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
174 words
A method for forming a conductor pattern, comprising the steps of: forming a conductive layer on a semiconductor substrate; forming a first masking metal film on the conductive layer; after said forming of said first masking metal film, forming a photoresist film on the conductive layer; removing that portion of the photoresist film located on a conductor pattern forming region of the conductive layer to form a surface structure including a remaining portion of the photoresist film; forming a second masking metal film over the entire surface structure; removing the remaining portion of the photoresist film along with that portion of the second masking metal film formed thereon so that a portion of the second masking film remains on the conductor pattern forming region of the conductive layer to form a first masking metal pattern; forming a second masking metal pattern by subjecting the first masking metal film to anisotropic etching using the first masking metal pattern as a mask; and selectively removing the conductive layer by anisotropic etching to form the conductor pattern.
Claim 2
Independent Claim
174 words
A method for forming a conductor pattern, comprising the steps of: forming a conductive layer on a semiconductor substrate; forming a first masking metal film on the conductive layer; after said forming of said first masking metal film, forming a photoresist film on the conductive layer; removing that portion of the photoresist film located on a conductor pattern forming region of the conductive layer to form a surface structure including a remaining portion of the photoresist film; forming a second masking metal film over the entire surface structure; removing the remaining portion of the photoresist film along with that portion of the second masking metal film formed thereon so that a portion of the second masking film remains on the conductor pattern forming region of the conductive layer to form a first masking metal pattern; forming a second masking metal pattern by subjecting the first masking metal film to anisotropic etching using the first masking metal pattern as a mask; and selectively removing the conductive layer by anisotropic etching to form the conductor pattern.
Claim 3
Dependent Claim
25 words
The method according to claim 1, wherein said conductive layer is formed of a material adapted to constitute a Schottky junction with the semiconductor substrate.
Claim 4
Dependent Claim
54 words
The method according to claim 1, wherein said conductive layer is formed of a material selected from the group consisting of gold, titanium, aluminum, titanium nitride, tungsten nitride, polycrystalline silicon, a two-layer structure of titanium and gold, a two-layer structure of titanium nitride and gold, and a two-layer structure of tungsten nitride and gold.
Claim 5
Dependent Claim
23 words
The method according to claim 1, wherein said anisotropic etching for selectively removing the conductive layer is reactive ion etching or ion milling.
Claim 6
Dependent Claim
29 words
The method according to claim 1, wherein said second masking metal film is formed of a material selected from the group consisting of gold, titanium, aluminum, tungsten, and molybdenum.
Claim 7
Dependent Claim
36 words
The method according to claim 1, wherein said first masking metal film is formed of a material having etching selectivity for materials from which both the conductive layer and the second masking metal film are formed.
Claim 8
Dependent Claim
29 words
The method according to claim 6, wherein said first masking metal film is formed of a material selected from the group consisting of gold, titanium, aluminum, tungsten, and molybdenum.
References Cited (Backward Citations)
US4448800A
Cited
US4586063A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-22 | 1990-12-22 | 1991-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-22 | 1994-12-22 | 1995-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-22 | 1998-12-22 | 1999-06-23 | $7700.00 | Window Closed / Lapsed |