EP0757377A2
Expired / Lapsed
EP
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Semiconductor substrate and fabrication method for the same
Assignee: Canon Inc
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Filing: 1996-07-31
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Granted: —
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Expires: 2016-07-31
Abstract
Abstract A method for fabricating a semiconductor substrate comprises the steps of employing a diffusion method to diffuse, in a silicon substrate, an element, which is capable of controlling a conductive type, and to form a diffused region, forming a porous layer in the diffused region, forming a non-porous single crystal layer on the porous layer, bonding the non-porous single crystal layer to a base substrate, while an insulation layer is provided either on a surface to be bonded of the non-porous single crystal layer or on a surface to be bonded of the base substrate, and removing the porous layer.
Inventors
- 👤 Kiyofumi Sakaguchi
- 👤 Takao Yonehara
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 11:40
CPC Classifications
H; H10; H10P; H10P32/00; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1922; H10W; H10W10/00; H10W10/10; H10W10/181; Y; Y10; Y10S; Y10S438/00; Y10S438/96
Claims Analysis
Total Claims: 43
Claim 1
Independent Claim
100 words
A method for fabricating a semiconductor substrate comprising the steps of: employing a diffusion method to diffuse, in a silicon substrate, an element, which is capable of controlling a conductive type, and to form a diffused region; forming a porous layer in said diffused region; forming a non-porous single crystal layer on said porous layer; bonding said non-porous single crystal layer to a base substrate, while an insulation layer is provided either on a surface to be bonded of said non-porous single crystal layer or on a surface to be bonded of said base substrate; and removing said porous layer.
Claim 2
Independent Claim
124 words
A method for fabricating a semiconductor substrate comprising the steps of: employing a diffusion method to diffuse an element, which is capable of controlling a conductive type, in a first surface of a silicon substrate and in a second surface on a reverse side of said first surface, and to form a diffused region; forming a porous layer in said diffused region that is formed on said first surface; forming a non-porous single crystal layer on said porous layer; bonding said non-porous single crystal layer and a base substrate, while an insulation layer is provided either on a surface to be bonded of said non-porous single crystal layer or on a surface to be bonded of said base substrate; and removing said porous layer.
Claim 3
Independent Claim
36 words
A method for fabricating a semiconductor substrate according to claims 1 or 2, wherein said element that is capable of controlling said conductive type is an element that is capable of controlling a conductive N-type silicon.
Claim 4
Dependent Claim
33 words
A method for fabricating a semiconductor substrate according to claim 3, wherein said element that is capable of controlling said conductive type is selected from a group consisting of P, As and Sb.
Claim 5
Independent Claim
37 words
A method for fabricating a semiconductor substrate according to claims 1 or 2, wherein said element that is capable of controlling said conductive type is an element that is capable of controlling a conductive P-type of silicon.
Claim 6
Dependent Claim
24 words
A method for fabricating a semiconductor substrate according to claim 5, wherein said element that is capable of controlling said conductive type is B.
Claim 7
Independent Claim
29 words
A method for fabricating a semiconductor substrate according to claims 1 or 2, wherein said diffusion method is a process for thermally diffusing said element in a silicon substrate.
Claim 8
Dependent Claim
32 words
A method for fabricating a semiconductor substrate according to claim 6, wherein said element that is capable of controlling said conductive type is supplied while a gas is used as a source.
Claim 9
Dependent Claim
20 words
A method for fabricating a semiconductor substrate according to claim 8, wherein said gas is B 2 H 6 .
Claim 10
Dependent Claim
32 words
A method for fabricating a semiconductor substrate according to claim 6, wherein said element that is capable of controlling said conductive type is supplied while a liquid is used as a source.
Claim 11
Dependent Claim
18 words
A method for fabricating a semiconductor substrate according to claim 10, wherein said liquid is BBr 3 .
Claim 12
Dependent Claim
32 words
A method for fabricating a semiconductor substrate according to claim 6, wherein said element that is capable of controlling said conductive type is supplied while a solid is used as a source.
Claim 13
Dependent Claim
20 words
A method for fabricating a semiconductor substrate according to claim 12, wherein said solid is B 2 O 3 .
Claim 14
Dependent Claim
33 words
A method for fabricating a semiconductor substrate according to claim 6, wherein said element that is capable of controlling said conductive type is supplied from a solid material formed on said silicon substrate.
Claim 15
Dependent Claim
25 words
A method for fabricating a semiconductor substrate according to claim 14, wherein said solid material is selected from CVD film, BSG and spin coated film.
Claim 16
Independent Claim
61 words
A method for fabricating a semiconductor substrate according to claims 1 or 2, wherein a concentration of said element that is capable of controlling said conductive type and that is contained in said diffusion layer is so adjusted that said concentration lies within a range of from 5.0 × 10 16 /cm 3 to 5.0 × 10 20 /cm 3 .
Claim 17
Dependent Claim
59 words
A method for fabricating a semiconductor substrate according to claim 16, wherein said concentration of said element that is capable of controlling said conductive type and that is contained in said diffusion layer is so adjusted that said concentration lies within a range of from 1.0 × 10 17 /cm 3 to 2.0 × 10 20 /cm 3 .
Claim 18
Dependent Claim
59 words
A method for fabricating a semiconductor substrate according to claim 17, wherein said concentration of said element that is capable of controlling said conductive type and that is contained in said diffusion layer is so adjusted that said concentration lies within a range of from 5.0 × 10 17 /cm 3 to 1.0 × 10 20 /cm 3 .
Claim 19
Independent Claim
25 words
A method for fabricating a semiconductor substrate according to claims 1 or 2, wherein a thickness of said diffusion layer is 500 Å or greater.
Claim 20
Independent Claim
29 words
A method for fabricating a semiconductor substrate according to claims 1 or 2, wherein porosity of said porous layer is so controlled that said porosity is 50% or lower.
Claim 21
Dependent Claim
33 words
A method for fabricating a semiconductor substrate according to claim 20, wherein said porosity of said porous layer is so controlled that said porosity lies in a range of from 1% to 40%.
Claim 22
Dependent Claim
33 words
A method for fabricating a semiconductor substrate according to claim 21, wherein said porosity of said porous layer is so controlled that said porosity lies in a range of from 5% to 30%.
Claim 23
Independent Claim
25 words
A method for fabricating a semiconductor substrate according to claims 1 or 2, wherein said non-porous single crystal layer is a single crystal Si layer.
Claim 24
Independent Claim
26 words
A method for fabricating a semiconductor substrate according to claims 1 or 2, wherein said non-porous single crystal layer is a single crystal compound semiconductor layer.
Claim 25
Dependent Claim
38 words
A method for fabricating a semiconductor substrate according to claim 23, wherein said insulation layer is selected from a group comprising a thermal oxide film, a deposited SiO 2 film and a deposited Si 3 N 4 film.
Claim 26
Dependent Claim
26 words
A method for fabricating a semiconductor substrate according to claim 25, wherein said insulation layer is formed on a side of said non-porous single crystal layer.
Claim 27
Dependent Claim
28 words
A method for fabricating a semiconductor substrate according to claim 26, wherein said insulation layer is formed by thermally oxidizing a surface of said single crystal silicon layer.
Claim 28
Independent Claim
23 words
A method for fabricating a semiconductor substrate according to claims 1 or 2, wherein said base substrate is a single crystal silicon substrate.
Claim 29
Dependent Claim
29 words
A method for fabricating a semiconductor substrate according to claim 28, wherein an oxide layer is formed on a face of said base substrate that is to be bonded.
Claim 30
Dependent Claim
29 words
A method for fabricating a semiconductor substrate according to claim 28, wherein said face of said base substrate that is to be bonded is formed of single crystal silicon.
Claim 31
Independent Claim
21 words
A method for fabricating a semiconductor substrate according to claims 1 or 2, wherein said base substrate is made of glass.
Claim 32
Dependent Claim
24 words
A method for fabricating a semiconductor substrate according to claim 25, wherein said insulation layer is formed on a side of said base support.
Claim 33
Dependent Claim
25 words
A method for fabricating a semiconductor substrate according to claim 32, wherein said insulation layer is formed by thermally oxidizing a single crystal silicon substrate.
Claim 34
Dependent Claim
19 words
A method for fabricating a semiconductor substrate according to claim 32, wherein said insulation layer constitutes a glass substrate.
Claim 35
Dependent Claim
27 words
A method for fabricating a semiconductor substrate according to claim 32, wherein bonding is performed without said insulation layer being formed on said non-porous single crystal layer.
Claim 36
Dependent Claim
32 words
A method for fabricating a semiconductor substrate according to claim 23, wherein said non-porous silicon layer is formed by epitaxial growth after interior walls of pores of said porous layer are oxidized.
Claim 37
Dependent Claim
35 words
A method for fabricating a semiconductor substrate according to claim 36, wherein said non-porous silicon layer is formed by epitaxial growth after a thermal process is performed on said porous layer in a hydrogen atmosphere.
Claim 38
Independent Claim
54 words
A method for fabricating a semiconductor substrate according to claims 1 or 2, wherein said porous layer is removed by using hydrogen fluoride, a mixture of hydrogen fluoride and, at least, either alcohol or hydrogen peroxide, buffered hydrogen fluoride, or a mixture of buffered hydrogen fluoride and, at least, either alcohol or hydrogen peroxide.
Claim 39
Independent Claim
29 words
A method for fabricating a semiconductor substrate according to claims 1 or 2, wherein a thermal process is performed in a hydrogen atmosphere after said porous layer is removed.
Claim 40
Dependent Claim
57 words
A method for fabricating a semiconductor substrate according to claim 2, wherein a plurality of silicon substrates, each of which has said solid material formed on said first surface, are arranged and heated in a furnace to form said diffused region on said first surface and on said second surface of each of said plurality of substrates.
Claim 41
Dependent Claim
16 words
A semiconductor substrate produced by a method according to any one of claims 1 to 40.
Claim 42
Dependent Claim
11 words
A semiconductor device comprising a semiconductor substrate according to claim 41.
Claim 43
Independent Claim
35 words
A method of producing a semiconductor device which comprises steps of: fabricating a semiconductor substrate according to any of claims 1 to 40; and producing a semiconductor element at the surface of said semiconductor substrate.
References Cited (Backward Citations)
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