US5863829A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for fabricating SOI substrate
Assignee: Sumco Techxiv Corp
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Filing: 1996-11-13
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Granted: 1999-01-26
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Expires: 2016-11-13
Abstract
Abstract The present invention provides a process for fabricating an SOI substrate with no peripheral scratches and with enhanced fabrication efficiency. The present process includes bonding a semiconductor wafer of an active substrate 1 and a semiconductor base wafer 2 to form a bonded wafer 4; surface-grinding the active substrate 1; spin etching the surface-ground active substrate 1; and PACE processing the etched active substrate 1 to form the active substrate into a thin film and simultaneously, to remove the non-bonded peripheral portion of the bonded wafer 4.
Inventors
- 👤 Yuichi Nakayoshi
- 👤 Hiroaki Yamamoto
- 👤 Akihiro Ishii
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:13
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1914; Y; Y10; Y10S; Y10S438/00; Y10S438/977
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
75 words
A process for fabricating an SOI substrate, comprising subjecting a bonded wafer, in which the bonded wafer is composed of a semiconductor wafer of an active substrate bonded on by a semiconductor base wafer, to PACE (plasma assisted chemical etching) process to form the active substrate into a thin film so as to obtain the SOI substrate, characterized in that a non-bonded peripheral portion of the bonded wafer is simultaneously removed by the PACE process.
Claim 2
Dependent Claim
75 words
A process for fabricating an SOI substrate, comprising subjecting a bonded wafer, in which the bonded wafer is composed of a semiconductor wafer of an active substrate bonded on by a semiconductor base wafer, to PACE (plasma assisted chemical etching) process to form the active substrate into a thin film so as to obtain the SOI substrate, characterized in that a non-bonded peripheral portion of the bonded wafer is simultaneously removed by the PACE process.
Claim 3
Dependent Claim
84 words
A process for fabricating an SOI substrate, characterized in that the process comprises the following steps of: (1) bonding a semiconductor wafer of an active substrate and a semiconductor base wafer to form a bonded wafer; (2) surface-grinding the active substrate of the bonded wafer; (3) etching the surface-ground active substrate by spin etching; and (4) PACE processing the etched active substrate to form the etched active substrate into a thin film and simultaneously to remove a non-bonded peripheral portion of the bonded wafer.
Claim 4
Dependent Claim
84 words
A process for fabricating an SOI substrate, characterized in that the process comprises the following steps of: (1) bonding a semiconductor wafer of an active substrate and a semiconductor base wafer to form a bonded wafer; (2) surface-grinding the active substrate of the bonded wafer; (3) etching the surface-ground active substrate by spin etching; and (4) PACE processing the etched active substrate to form the etched active substrate into a thin film and simultaneously to remove a non-bonded peripheral portion of the bonded wafer.
Claim 5
Dependent Claim
25 words
The process for fabricating an SOI substrate as. claimed in claim 2, wherein an etching solution used in the spin etching is a mixed acid.
Claim 6
Dependent Claim
26 words
The process for fabricating an SOI substrate as claimed in claim 3, wherein the mixed acid comprises hydrofluoric acid, nitric acid, n-phosphoric acid and sulfuric acid.
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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) | 2002-01-25 | 2002-07-27 | 2003-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-01-25 | 2006-07-27 | 2007-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-01-25 | 2010-07-27 | 2011-01-26 | $7700.00 | Window Closed / Lapsed |