US5405802A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of fabricating a semiconductor substrate
Assignee: Canon Inc
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Filing: 1994-05-25
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Granted: 1995-04-11
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Expires: 2014-05-25
Abstract
Abstract A process for preparing a semiconductor substrate comprises a step of porousifying a silicon monocrystalline substrate to form a porous layer, a step of making a silicon monocrystalline thin film to epitaxially grow on a surface of the porous layer, a step of oxidizing the surface of the epitaxial growth layer, a step of forming a deposited film on the oxidized surface, thereby obtainig a first substrate, a step of closely contacting the deposited film of the first substrate to a second substrate, a step of heat treating the closely contacted substrates and a step of selectively etching the porous layer.
Inventors
- 👤 Kenji Yamagata
- 👤 Takao Yonehara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 06:15
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/60; H10P50/64; H10P50/642; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1914; H10P90/1922; H10W; H10W10/00; H10W10/10; H10W10/181; H10P72/00; H10P72/70; H10P72/74; H10P72/7432; Y; Y10; Y10S; Y10S438/00; Y10S438/96; Y10S438/977; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249967
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
102 words
A process for preparing a semiconductor substrate, which comprises a step of porousifying a silicon monocrystalline substrate to form a porous layer, a step of making a silicon monocrystalline thin film to epitaxially grow on a surface of the porous layer, a step of oxidizing the surface of the epitaxial growth layer, a step of forming a deposited film on the oxidized surface, thereby obtaining a first substrate, a step of closely contacting the deposited film of the first substrate to a second substrate, a step of heat treating the closely contacted substrates and a step of selectively etching the porous layer.
Claim 2
Dependent Claim
102 words
A process for preparing a semiconductor substrate, which comprises a step of porousifying a silicon monocrystalline substrate to form a porous layer, a step of making a silicon monocrystalline thin film to epitaxially grow on a surface of the porous layer, a step of oxidizing the surface of the epitaxial growth layer, a step of forming a deposited film on the oxidized surface, thereby obtaining a first substrate, a step of closely contacting the deposited film of the first substrate to a second substrate, a step of heat treating the closely contacted substrates and a step of selectively etching the porous layer.
Claim 3
Dependent Claim
16 words
A process according to claim 1, wherein the deposited film is a film containing silicon atoms.
Claim 4
Dependent Claim
30 words
A process according to claim 2, wherein the deposited film is selected from a polycrystalline silicon film, an amorphous silicon film, a silicon oxide film and a silicon nitride film.
Claim 5
Dependent Claim
14 words
A process according to claim 1, where the deposited film is formed by CVD.
Claim 6
Dependent Claim
18 words
A process according to claim 1, wherein the deposited film has a thickness of 2 μm or more.
Claim 7
Dependent Claim
18 words
A process according to claim 5, wherein the deposited film has a thickness of 10 μm or more.
Claim 8
Dependent Claim
18 words
A process according to claim 1, wherein the heat treatment is carried out at 800° C. or more.
Claim 9
Dependent Claim
28 words
A process according to claim 1, wherein the oxide film obtained by oxidizing the surface of the epitaxial layer has a thickness of 0.5 μm to 1.0 μm.
Claim 10
Dependent Claim
14 words
A process according to claim 1, wherein the second substrates is a transparent substrate.
Claim 11
Dependent Claim
14 words
The process according to claim 1, including conducting the step of porousifying by anodization.
Claim 12
Dependent Claim
12 words
The process according to claim 9, wherein the second substrate comprises quartz.
Claim 13
Dependent Claim
12 words
The process according to claim 1, wherein the second substrate comprises silicon.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1998-04-10 | 1998-10-10 | 1999-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-04-10 | 2002-10-10 | 2003-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-04-10 | 2006-10-10 | 2007-04-11 | $7700.00 | Window Closed / Lapsed |