US4560642A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing a semiconductor device
Assignee: Toshiba Corp
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Filing: 1984-07-19
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Granted: 1985-12-24
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Expires: 2004-07-19
Abstract
Abstract A method of manufacturing a semiconductor device which comprises the step of applying a silicon carbide film having a prescribed perforated pattern as a masking film selectively to etch a silicon dioxide film or diffuse an impurity into a substrate.
Inventors
- 👤 Toshio Yonezawa
- 👤 Takashi Ajima
- 👤 Shunichi Hiraki
- 👤 Yutaka Koshino
- 👤 Yoshitami Oka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 06:31
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/69; H10P14/6903; H10P14/6905; H10P14/63; H10P14/6326; H10P14/6328; H10P14/6329; H10P14/6334; H10P14/6336; H10P14/66; H10P14/662; H10P14/692; H10P14/6921; H10P14/69215; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10P50/73; H10P76/00; H10P76/40; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/945; Y10S438/948; Y10S438/95; Y10S438/951
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
134 words
A method of preparing a silicon dioxide film perforated in a prescribed pattern, the film to be used as a mask on the surface of semiconductor material for manufacture of a dimensionally precise semiconductor device, the method comprising: (a) forming a silicon dioxide film substantially covering the surface of the semiconductor material; (b) adheringly covering said silicon dioxide film with a silicon carbide mask comprising a silicon carbide film perforated in the prescribed pattern wherein the silicon carbide mask is formed by a "lift off" process with the prescribed perforated pattern; (c) selectively etching said silicon dioxide film using hydrofluoric acid or ammonium fluoride through the perforations having the prescribed pattern in said silicon carbide mask, thereby providing a dimensionally precise silicon dioxide mask for diffusion of an impurity or deposition of an electrode.
Claim 2
Independent Claim
134 words
A method of preparing a silicon dioxide film perforated in a prescribed pattern, the film to be used as a mask on the surface of semiconductor material for manufacture of a dimensionally precise semiconductor device, the method comprising: (a) forming a silicon dioxide film substantially covering the surface of the semiconductor material; (b) adheringly covering said silicon dioxide film with a silicon carbide mask comprising a silicon carbide film perforated in the prescribed pattern wherein the silicon carbide mask is formed by a "lift off" process with the prescribed perforated pattern; (c) selectively etching said silicon dioxide film using hydrofluoric acid or ammonium fluoride through the perforations having the prescribed pattern in said silicon carbide mask, thereby providing a dimensionally precise silicon dioxide mask for diffusion of an impurity or deposition of an electrode.
Claim 3
Dependent Claim
79 words
The method as in claim 1 wherein said "lift off" process includes the sub-steps of (i) forming a photoresist film on said silicon dioxide layer, said photoresist film being perforated in the prescribed pattern to expose portions of said silicon dioxide layer, (ii) depositing a layer of silicon carbide over said photoresist film and said exposed silicon dioxide layer portions, and (iii) removing said photoresist film together with the part of said silicon carbide layer overlying said photoresist film.
Claim 4
Dependent Claim
39 words
The method as in claim 2 wherein the thickness of said silicon carbide layer is less than the thickness of said photoresist film, and wherein said photoresist film and overlying silicon carbide layer part are removed using a solvent.
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FR1530218A
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US3904454A
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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) | 1988-12-23 | 1989-06-24 | 1989-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-23 | 1993-06-24 | 1993-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-23 | 1997-06-24 | 1997-12-24 | $7700.00 | Window Closed / Lapsed |