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Patent US4471525A successfully refreshed from Google Patents.
US4471525A
Expired / Lapsed
US
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Method for manufacturing semiconductor device utilizing two-step etch and selective oxidation to form isolation regions
Assignee: Toshiba Corp
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Filing: 1982-03-18
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Granted: 1984-09-18
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Expires: 2002-03-18
Abstract
Abstract Disclosed is a method for manufacturing a semiconductor device of high reliability, high performance and high integration with high yield. The method of this invention has the steps of forming at least one groove in a semiconductor substrate, forming a non-single-crystalline semiconductor film to cover an entire surface of the semiconductor substrate including an inner surface of the groove, selectively etching the non-single-crystalline semiconductor film so as to leave the non-single-crystalline semiconductor film on at least a side wall of the groove, and forming an oxide isolation layer in the groove by thermal oxidation.
Inventors
- 👤 Yoshitaka Sasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:48
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/61; H10P95/00; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/012; H10W10/0121; H10W10/0123; H10W10/014; H10W10/0142; H10W10/10; H10W10/13; H10W10/17; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/944
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
127 words
A method for manufacturing a semiconductor device comprising the steps of: forming at least one groove in a semiconductor substrate using a thin oxide film as a mask; expanding the width and depth of said groove using isotropic etching and simultaneously forming an overhang portion of said thin oxide film over the edge of said groove; forming a non-single-crystalline semiconductor film to cover an entire surface of said semiconductor substrate including an inner surface of said groove; selectively vertically etching said non-single-crystalline semiconductor film using reactive ion etching and using said overhang portion as a mask so as to leave said non-single-crystalline semiconductor film on a side wall of said groove under said overhang portion; and forming an oxide isolation layer in said groove by thermal oxidation.
Claim 2
Independent Claim
127 words
A method for manufacturing a semiconductor device comprising the steps of: forming at least one groove in a semiconductor substrate using a thin oxide film as a mask; expanding the width and depth of said groove using isotropic etching and simultaneously forming an overhang portion of said thin oxide film over the edge of said groove; forming a non-single-crystalline semiconductor film to cover an entire surface of said semiconductor substrate including an inner surface of said groove; selectively vertically etching said non-single-crystalline semiconductor film using reactive ion etching and using said overhang portion as a mask so as to leave said non-single-crystalline semiconductor film on a side wall of said groove under said overhang portion; and forming an oxide isolation layer in said groove by thermal oxidation.
Claim 3
Dependent Claim
39 words
A method according to claim 1, wherein said non-single-crystalline semiconductor film is a member selected from the group consisting of an undoped polycrystalline silicon film, an impurity-doped polycrystalline silicon film, an amorphous silicon film and a metal silicide film.
Claim 4
Dependent Claim
18 words
A method according to claim 1, wherein said non-single-crystalline semiconductor film is selectively etched by reactive ion etching.
Claim 5
Dependent Claim
31 words
A method according to claim 1, wherein oxidation is performed prior to the formation of said non-single-crystalline semiconductor film to form an oxide film on the inner surface of said groove.
Claim 6
Dependent Claim
28 words
A method according to claim 1, wherein said semiconductor substrate is selectively etched to form said groove, using an insulating film of a predetermined pattern as a mask.
Claim 7
Dependent Claim
24 words
A method according to claim 5, wherein said semiconductor substrate is etched by isotropic etching to form an over-hang of an insulating film pattern.
Claim 8
Dependent Claim
26 words
A method according to claim 1, wherein said non-single-crystalline semiconductor film is oxidized by the thermal oxidation to fill said groove with an oxide formed therefrom.
Claim 9
Independent Claim
39 words
A method according to any one of claims 1 to 7, wherein an oxidation-resistive insulating film is formed to cover said semiconductor substrate including the inner surface of said groove prior to the formation of said non-single-crystalline semiconductor film.
Claim 10
Dependent Claim
28 words
A method according to claim 8, wherein said oxidation-resistive insulating film is a member selected from the group consisting of a silicon nitride film and an alumina 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) | 1987-09-18 | 1988-03-19 | 1988-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-18 | 1992-03-19 | 1992-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-18 | 1996-03-19 | 1996-09-18 | $7700.00 | Window Closed / Lapsed |