Patent US4276114A successfully refreshed from Google Patents.
US4276114A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor substrate and a manufacturing method thereof
Assignee: De Nora SpA
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Filing: 1979-02-06
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Granted: 1981-06-30
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Expires: 1999-02-06
Abstract
Abstract This invention relates to a semiconductor substrate and a method of manufacturing the same. In a semiconductor manufacturing process for a Si single crystal wafer or the like, before the step of mirror polishing, the rear surface of a Si wafer is ground to form a damaged layer having a certain fixed thickness, the Si wafer is subsequently etched by chemical etching if desired, and the rear surface is further formed with an oxide film by thermal oxidation if desired, whereby a semiconductor substrate exhibiting an intense gettering effect is manufactured.
Inventors
- 👤 Yukio Takano
- 👤 Masahiko Ogirima
- 👤 Shigeru Aoki
- 👤 Michiyoshi Maki
- 👤 Shigeo Kato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:12
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/12; H10P36/00; H10P36/03; H10P95/00; Y; Y10; Y10S; Y10S148/00; Y10S148/061; Y10S438/00; Y10S438/974; Y10T; Y10T428/00; Y10T428/31
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
91 words
A method of manufacturing a semiconductor substrate comprising the step of cutting a semiconductor crystal rod into the shape of a wafer, to obtain a semiconductor wafer, the step of grinding a rear surface of said semiconductor wafer with plane wheel means, to form a damaged layer whose maximum depth lies in a range of 2 μm to 20 μm in the rear surface, the step of etching the ground surface to decrease the curvature of said semiconductor wafer, and the step of mirror-polishing a front surface of the semiconductor wafer.
Claim 2
Independent Claim
91 words
A method of manufacturing a semiconductor substrate comprising the step of cutting a semiconductor crystal rod into the shape of a wafer, to obtain a semiconductor wafer, the step of grinding a rear surface of said semiconductor wafer with plane wheel means, to form a damaged layer whose maximum depth lies in a range of 2 μm to 20 μm in the rear surface, the step of etching the ground surface to decrease the curvature of said semiconductor wafer, and the step of mirror-polishing a front surface of the semiconductor wafer.
Claim 3
Dependent Claim
23 words
A method of manufacturing a semiconductor substrate according to claim 1, wherein the semiconductor wafer is heat-treated for oxidation after the etching step.
Claim 4
Dependent Claim
23 words
A method of manufacturing a semiconductor substrate according to claim 1 or 2, wherein said semiconductor substrate is a silicon single crystal substrate.
Claim 5
Dependent Claim
26 words
A method of manufacturing a semiconductor substrate according to claim 1 or 2 wherein said semiconductor substrate is provided with a semiconductor epitaxial growth layer thereon.
Claim 6
Dependent Claim
24 words
A method of manufacturing a semiconductor substrate according to claim 1, wherein said semiconductor substrate is provided with at least one semiconductor device thereon.
Claim 7
Dependent Claim
37 words
A method of manufacturing a semiconductor substrate according to claim 1 wherein the grinding step forms the damaged layer of a maximum depth of 2 μm to 15 μm in the rear surface of said semiconductor substrate.
Claim 8
Dependent Claim
32 words
A method of manufacturing a semiconductor substrate according to claim 1 or 2 wherein the grinding step is carried out with plane wheel means of less than a grit size of 2000.
Claim 9
Dependent Claim
24 words
A method of manufacturing a semiconductor substrate according to claim 3, wherein said semiconductor substrate is provided with a semiconductor epitaxial growth layer thereon.
Claim 10
Dependent Claim
24 words
A method of manufacturing a semiconductor substrate according to claim 3, wherein said semiconductor substrate is provided with at least one semiconductor device thereon.
Claim 11
Dependent Claim
37 words
A method of manufacturing a semiconductor substrate according to claim 3, wherein the grinding step forms the damaged layer of a maximum depth of 2 μm to 15 μm in the rear surface of said semiconductor substrate.
Claim 12
Dependent Claim
30 words
A method of manufacturing a semiconductor substrate according to claim 3, wherein the grinding step is carried out with plane wheel means of less than a grit size of 2000.
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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) | 1984-06-29 | 1984-12-29 | 1985-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-29 | 1988-12-29 | 1989-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-29 | 1992-12-29 | 1993-06-30 | $7700.00 | Window Closed / Lapsed |