EP0753886A1
Expired / Lapsed
EP
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Process for producing semiconductor substrate
Assignee: Canon Inc
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Filing: 1996-07-12
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Granted: —
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Expires: 2016-07-12
Abstract
Abstract A process for producing a semiconductor substrate is provided which comprises providing a first substrate made of silicon having a porous silicon layer formed thereon by making porous the substrate silicon and a nonporous monocrystalline silicon layer epitaxially grown on the porous silicon layer, laminating the first substrate onto a second substrate in a state that at least one of lamination faces of the first and the second substrates has a silicon oxide layer and the nonporous monocrystalline silicon layer is interposed between the laminated substrates, and removing the porous silicon layer by etching, wherein the porous silicon layer is removed by etching with an etchant which etches the nonporous monocrystalline silicon layer and the silicon oxide layer at respective etching rates of not more than 10 angstroms per minute.
Inventors
- 👤 Kenji c/o Canon K.K. Yamagata
- 👤 Takao C/O Canon K.K. Yonehara
- 👤 Nobuhiko c/o Canon K.K. Sato
- 👤 Kiyofumi c/o Canon K.K. Sakaguchi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 13:44
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1922; H10P90/12; H10P90/15; H10P90/1908; H10W; H10W10/00; H10W10/10; H10W10/181
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
127 words
A process for producing a semiconductor substrate comprising providing a first substrate made of silicon having a porous silicon layer formed thereon by making porous the substrate silicon and a nonporous monocrystalline silicon layer epitaxially grown on the porous silicon layer, laminating the first substrate onto a second substrate in a state that at least one of lamination faces of the first and the second substrates has a silicon oxide layer and the nonporous monocrystalline silicon layer is interposed between the laminated substrates, and removing the porous silicon layer by etching, wherein the porous silicon layer is removed by etching with an etchant which etches the nonporous monocrystalline silicon layer and the silicon oxide layer at respective etching rates of not more than 10 angstroms per minute.
Claim 2
Dependent Claim
20 words
The process for producing a semiconductor substrate according to claim 1, wherein the porous silicon layer is formed by anodization.
Claim 3
Dependent Claim
26 words
The process for producing a semiconductor substrate according to either of claims 1 or 2, wherein the silicon oxide layer is formed on the first substrate.
Claim 4
Dependent Claim
32 words
The process for producing a semiconductor substrate according to claim 3, wherein the silicon oxide layer is formed by thermal oxidation of the surface of the epitaxially grown nonporous monocrystalline silicon layer.
Claim 5
Dependent Claim
22 words
The process for producing a semiconductor substrate according to claim 3 or 4, wherein the second substrate is a monocrystalline silicon substrate.
Claim 6
Dependent Claim
27 words
The process for producing a semiconductor substrate according to claim 5, wherein also a silicon oxide layer is formed on the lamination face of the second substrate.
Claim 7
Dependent Claim
24 words
The process for producing a semiconductor substrate according to claim 5, wherein the lamination face of the second substrate is constituted of monocrystalline silicon.
Claim 8
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 3 or 4, wherein the second substrate is a glass substrate.
Claim 9
Dependent Claim
22 words
The process for producing a semiconductor substrate according to claim 1, wherein the silicon oxide layer is formed on the second substrate.
Claim 10
Dependent Claim
35 words
The process for producing a semiconductor substrate according to claim 9, wherein said second substrate is a monocrystalline silicon substrate and the silicon oxide layer is formed by thermal oxidation of the monocrystalline silicon substrate.
Claim 11
Dependent Claim
20 words
The process for producing a semiconductor substrate according to claim 9, wherein the silicon oxide layer constitutes a glass substrate.
Claim 12
Dependent Claim
31 words
The process for producing a semiconductor substrate according to any of claims 9 to 11, wherein the lamination face of the first substrate is the epitaxially grown nonporous monocrystalline silicon layer.
Claim 13
Dependent Claim
37 words
The process for producing a semiconductor substrate according to any preceding claim, wherein the nonporous monocrystalline silicon layer is formed by epitaxial growth after the inner walls of the pores of the porous layer have been oxidized.
Claim 14
Dependent Claim
32 words
The process for producing a semiconductor substrate according to claim 13, wherein the nonporous monocrystalline silicon layer is formed by epitaxial growth after the porous layer is heat-treated in a hydrogen atmosphere.
Claim 15
Dependent Claim
35 words
The process for producing a semiconductor substrate according to any preceding claim, wherein the etching of the porous silicon layer is conducted with a mixed etching solution composed of hydrofluoric acid and aqueous hydrogen peroxide.
Claim 16
Dependent Claim
40 words
The process for producing a semiconductor substrate according to any of claims 1 to 14, wherein the etching of the porous silicon layer is conducted with a mixed etching solution composed of hydrofluoric acid, nitric acid, and optionally acetic acid.
Claim 17
Dependent Claim
35 words
The process for producing a semiconductor substrate according to any of claims 1 to 14, wherein the etching of the porous silicon layer is conducted with an alkali or an organic alkali type etching solution.
Claim 18
Dependent Claim
40 words
The process for producing a semiconductor substrate according to any of claims 1 to 14, wherein the etching of the porous silicon layer is conducted with an aqueous TMAH solution of a concentration of not higher than about 50 ppm.
Claim 19
Dependent Claim
56 words
The process for producing a semiconductor substrate according to any of claims 1 to 14, wherein the etching of the porous silicon layer is conducted with a mixed solution of hydrofluoric acid and an aqueous hydrogen peroxide solution at a hydrofluoric acid concentration of not higher than about 0.5% relative to the aqueous hydrogen peroxide solution.
Claim 20
Dependent Claim
26 words
The process for producing a semiconductor substrate according to any preceding claim, wherein heat treatment is conducted in a hydrogen atmosphere after the removal by etching.
References Cited (Backward Citations)
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