Patent US522334A successfully refreshed from Google Patents.
US6136684A
Expired / Lapsed
US
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Semiconductor substrate and process for production thereof
Assignee: Canon Inc
•
Filing: 1996-07-19
•
Granted: 2000-10-24
•
Expires: 2016-07-19
Abstract
Abstract A process for producing a semiconductor substrate is provided which comprises providing a first member having a porous monocrystalline silicon layer and a nonporous monocrystalline silicon layer grown thereon, laminating the nonporous silicon layer of the first member onto a second member with interposition of an insulation layer provided on at least one lamination face of the first member and the second member, and removing the porous monocrystalline silicon layer by etching, wherein the nonporous monocrystalline silicon layer is grown at a low growth rate controlled such that the density of remaining pores on the crystal growth face is not more than 1000/cm2 at the time when the nonporous silicon layer has grown to a thickness corresponding to the diameter of the pores of the porous monocrystalline silicon layer.
Inventors
- 👤 Nobuhiko Sato
- 👤 Takao Yonehara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:40
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/20; H10P14/29; H10P14/2901; H10P14/2902; H10P14/2905; H10P14/24; H10P14/27; H10P14/271; H10P14/276; H10P14/2922; H10P14/32; H10P14/3202; H10P14/3204; H10P14/3211; H10P14/3242; H10P14/3256; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P14/36; H10P14/3602; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1922; H10W; H10W10/00; H10W10/10; H10W10/181
Claims Analysis
Total Claims: 113
Claim 1
Independent Claim
77 words
A process for producing a semiconductor substrate comprising: growing on a porous silicon layer a nonporous monocrystalline silicon layer in an atmosphere containing at least silicon source gas and hydrogen gas and controlling growth rate such that the density of remaining pores on the crystal growth face is less than 1000/cm 2 at the time when a monocrystalline silicon layer has grown to a thickness corresponding to the diameter of the pores of the porous silicon layer.
Claim 2
Dependent Claim
77 words
A process for producing a semiconductor substrate comprising: growing on a porous silicon layer a nonporous monocrystalline silicon layer in an atmosphere containing at least silicon source gas and hydrogen gas and controlling growth rate such that the density of remaining pores on the crystal growth face is less than 1000/cm 2 at the time when a monocrystalline silicon layer has grown to a thickness corresponding to the diameter of the pores of the porous silicon layer.
Claim 3
Dependent Claim
34 words
The process for producing a semiconductor substrate according to claim 1, wherein the nonporous monocrystalline silicon layer is grown on the porous silicon layer in a growth furnace by feeding a source gas thereto.
Claim 4
Dependent Claim
24 words
The process for producing a semiconductor substrate according to claim 2, wherein the source gas is selected from silane, dichlorosilane, trichlorosilane, tetrachlorosilane, and disilane.
Claim 5
Dependent Claim
36 words
The process for producing a semiconductor substrate according to any of claims 1 to 3, wherein the porous silicon layer is heated in a nonoxidative atmosphere prior to the growth of the nonporous monocrystalline silicon layer.
Claim 6
Dependent Claim
19 words
The process for producing a semiconductor substrate according to claim 4, wherein the nonoxidative atmosphere is a hydrogen atmosphere.
Claim 7
Dependent Claim
33 words
The process for producing a semiconductor substrate according to claim 4, wherein the process comprises a step of removing a natural oxide film prior to the growth of the nonporous monocrystalline silicon layer.
Claim 8
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 6, wherein the growth rate is not higher than 20 nm/min.
Claim 9
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 4, wherein the growth rate is not higher than 20 nm/min.
Claim 10
Dependent Claim
33 words
The process for producing a semiconductor substrate according to claim 5, wherein the process comprises a step of removing a natural oxide film prior to the growth of the nonporous monocrystalline silicon layer.
Claim 11
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 5, wherein the growth rate is not higher than 20 nm/min.
Claim 12
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 9, wherein the growth rate is not higher than 20 nm/min.
Claim 13
Dependent Claim
37 words
The process for producing a semiconductor substrate according to any of claims 1 to 3, wherein the process comprises a step of removing a natural oxide film prior to the growth of the nonporous monocrystalline silicon layer.
Claim 14
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 12, wherein the growth rate is not higher than 20 nm/min.
Claim 15
Dependent Claim
57 words
The process for producing a semiconductor substrate according to any of claims 1 to 3, wherein the process comprises steps of forming an ultrathin film on a wall of the porous silicon layer, and removing an oxide film on the external surface of the porous silicon layer prior to the growth of the nonporous monocrystalline silicon layer.
Claim 16
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 14, wherein the growth rate is not higher than 20 nm/min.
Claim 17
Dependent Claim
65 words
The process for producing a semiconductor substrate according to any of claims 1 to 3, wherein the process comprises steps of forming an ultrathin film on a wall of the porous silicon layer, removing an oxide film on the surface of the porous silicon layer, and heat-treating the porous silicon layer in a hydrogen atmosphere prior to the growth of the nonporous monocrystalline silicon layer.
Claim 18
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 16, wherein the growth rate is not higher than 20 nm/min.
Claim 19
Dependent Claim
25 words
The process for producing a semiconductor substrate according to any of claims 1 to 3, wherein the growth rate is not higher than 20 nm/min.
Claim 20
Dependent Claim
35 words
The process for producing a semiconductor substrate according to claim 2, wherein the porous silicon layer is heated to a temperature of 900° C. or higher during the growth of the nonporous monocrystalline silicon layer.
Claim 21
Dependent Claim
27 words
The process for producing a semiconductor substrate according to claim 1, wherein the diameter of the pores is the largest pore diameter of the porous silicon layer.
Claim 22
Dependent Claim
85 words
A process for producing a semiconductor substrate comprising: growing on a porous silicon layer a nonporous monocrystalline silicon layer at a first growth rate controlled such that the density of remaining pores on the crystal growth face is less than 1000/cm 2 at the time when a monocrystalline silicon layer has grown to a thickness corresponding to the diameter of the pores of the porous silicon layer, and thereafter growing the nonporous monocrystalline silicon layer at a higher growth rate than said first growth rate.
Claim 23
Dependent Claim
85 words
A process for producing a semiconductor substrate comprising: growing on a porous silicon layer a nonporous monocrystalline silicon layer at a first growth rate controlled such that the density of remaining pores on the crystal growth face is less than 1000/cm 2 at the time when a monocrystalline silicon layer has grown to a thickness corresponding to the diameter of the pores of the porous silicon layer, and thereafter growing the nonporous monocrystalline silicon layer at a higher growth rate than said first growth rate.
Claim 24
Dependent Claim
34 words
The process for producing a semiconductor substrate according to claim 21, wherein the nonporous monocrystalline silicon layer is grown on the porous silicon layer in a growth furnace by feeding a source gas thereto.
Claim 25
Dependent Claim
24 words
The process for producing a semiconductor substrate according to claim 22, wherein the source gas is selected from silane, dichlorosilane, trichlorosilane, tetrachlorosilane, and disilane.
Claim 26
Dependent Claim
36 words
The process for producing a semiconductor substrate according to any of claims 21 to 23, wherein the porous silicon layer is heated in a, nonoxidative atmosphere prior to the growth of the nonporous monocrystalline silicon layer.
Claim 27
Dependent Claim
19 words
The process for producing a semiconductor substrate according to claim 24, wherein the nonoxidative atmosphere is a hydrogen atmosphere.
Claim 28
Dependent Claim
33 words
The process for producing a semiconductor substrate according to claim 24, wherein the process comprises a step of removing a natural oxide film prior to the growth of the nonporous monocrystalline silicon layer.
Claim 29
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 26, wherein the growth rate is not higher than 20 nm/min.
Claim 30
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 24, wherein the growth rate is not higher than 20 nm/min.
Claim 31
Dependent Claim
33 words
The process for producing a semiconductor substrate according to claim 25, wherein the process comprises a step of removing a natural oxide film prior to the growth of the nonporous monocrystalline silicon layer.
Claim 32
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 25, wherein the growth rate is not higher than 20 nm/min.
Claim 33
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 29, wherein the growth rate is not higher than 20 nm/min.
Claim 34
Dependent Claim
37 words
The process for producing a semiconductor substrate according to any of claims 21 to 23, wherein the process comprises a step of removing a natural oxide film prior to the growth of the nonporous monocrystalline silicon layer.
Claim 35
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 32, wherein the growth rate is not higher than 20 nm/min.
Claim 36
Dependent Claim
57 words
The process for producing a semiconductor substrate according to any of claims 21 to 23, wherein the process comprises steps of forming an ultrathin film on a wall of the porous silicon layer, and removing an oxide film on the external surface of the porous silicon layer prior to the growth of the nonporous monocrystalline silicon layer.
Claim 37
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 34, wherein the growth rate is not higher than 20 nm/min.
Claim 38
Dependent Claim
65 words
The process for producing a semiconductor substrate according to any of claims 21 to 23, wherein the process comprises steps of forming an ultrathin film on a wall of the porous silicon layer, removing an oxide film on the surface of the porous silicon layer, and heat-treating the porous silicon layer in a hydrogen atmosphere prior to the growth of the nonporous monocrystalline silicon layer.
Claim 39
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 36, wherein the growth rate is not higher than 20 nm/min.
Claim 40
Dependent Claim
25 words
The process for producing a semiconductor substrate according to any of claims 21 to 23, wherein the growth rate is not higher than 20 nm/min.
Claim 41
Dependent Claim
35 words
The process for producing a semiconductor substrate according to claim 22, wherein the porous monocrystalline layer is heated to a temperature of 900° C. or higher during the growth of the nonporous monocrystalline silicon layer.
Claim 42
Dependent Claim
28 words
The process for producing a semiconductor substrate according to claim 21, wherein the diameter of the pores is the largest pore diameter of the porous monocrystalline silicon layer.
Claim 43
Dependent Claim
131 words
A process for producing a semiconductor substrate comprising: providing a first substrate having a porous silicon layer and a nonporous monocrystalline silicon layer grown thereon; laminating the nonporous silicon layer of the first substrate onto a second substrate with interposition of an insulation layer provided on at least one lamination face of the first substrate and the second substrate; and removing the porous silicon layer, wherein the nonporous monocrystalline silicon layer is grown in an atmosphere containing at least silicon source gas and hydrogen gas at a growth rate controlled such that the density of remaining pores on the crystal growth face is less than 1000/cm 2 at the time when a silicon layer has grown to a thickness corresponding to the diameter of the pores of the porous silicon layer.
Claim 44
Dependent Claim
131 words
A process for producing a semiconductor substrate comprising: providing a first substrate having a porous silicon layer and a nonporous monocrystalline silicon layer grown thereon; laminating the nonporous silicon layer of the first substrate onto a second substrate with interposition of an insulation layer provided on at least one lamination face of the first substrate and the second substrate; and removing the porous silicon layer, wherein the nonporous monocrystalline silicon layer is grown in an atmosphere containing at least silicon source gas and hydrogen gas at a growth rate controlled such that the density of remaining pores on the crystal growth face is less than 1000/cm 2 at the time when a silicon layer has grown to a thickness corresponding to the diameter of the pores of the porous silicon layer.
Claim 45
Dependent Claim
35 words
The process for producing a semiconductor substrate according to claim 41, wherein the nonporous monocrystalline silicon layer is grown on the porous monocrystalline silicon layer in a growth furnace by feeding a source gas thereto.
Claim 46
Dependent Claim
24 words
The process for producing a semiconductor substrate according to claim 42, wherein the source gas is selected from silane, dichlorosilane, trichlorosilane, tetrachlorosilane, and disilane.
Claim 47
Dependent Claim
36 words
The process for producing a semiconductor substrate according to any of claims 41 to 43, wherein the porous silicon layer is heated in a nonoxidative atmosphere prior to the growth of the nonporous monocrystalline silicon layer.
Claim 48
Dependent Claim
19 words
The process for producing a semiconductor substrate according to claim 44, wherein the nonoxidative atmosphere is a hydrogen atmosphere.
Claim 49
Dependent Claim
33 words
The process for producing a semiconductor substrate according to claim 44, wherein the process comprises a step of removing a natural oxide film prior to the growth of the nonporous monocrystalline silicon layer.
Claim 50
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 46, wherein the growth rate is not higher than 20 nm/min.
Claim 51
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 44, wherein the growth rate is not higher than 20 nm/min.
Claim 52
Dependent Claim
33 words
The process for producing a semiconductor substrate according to claim 45, wherein the process comprises a step of removing a natural oxide film prior to the growth of the nonporous monocrystalline silicon layer.
Claim 53
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 45, wherein the growth rate is not higher than 20 nm/min.
Claim 54
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 49, wherein the growth rate is not higher than 20 nm/min.
Claim 55
Dependent Claim
37 words
The process for producing a semiconductor substrate according to any of claims 41 to 43, wherein the process comprises a step of removing a natural oxide film prior to the growth of the nonporous monocrystalline silicon layer.
Claim 56
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 52, wherein the growth rate is not higher than 20 nm/min.
Claim 57
Dependent Claim
57 words
The process for producing a semiconductor substrate according to any of claims 41 to 43, wherein the process comprises steps of forming an ultrathin film on a wall of the porous silicon layer, and removing an oxide film on the external surface of the porous silicon layer prior to the growth of the nonporous monocrystalline silicon layer.
Claim 58
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 54, wherein the growth rate is not higher than 20 nm/min.
Claim 59
Dependent Claim
65 words
The process for producing a semiconductor substrate according to any of claims 41 to 43, wherein the process comprises steps of forming an ultrathin film on a wall of the porous silicon layer, removing an oxide film on the surface of the porous silicon layer, and heat-treating the porous silicon layer in a hydrogen atmosphere prior to the growth of the nonporous monocrystalline silicon layer.
Claim 60
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 56, wherein the growth rate is not higher than 20 nm/min.
Claim 61
Dependent Claim
25 words
The process for producing a semiconductor substrate according to any of claims 41 to 43, wherein the growth rate is not higher than 20 nm/min.
Claim 62
Dependent Claim
35 words
The process for producing a semiconductor substrate according to claim 42, wherein the porous silicon layer is heated to a temperature of 900° C. or higher during the growth of the nonporous monocrystalline silicon layer.
Claim 63
Dependent Claim
27 words
The process for producing a semiconductor substrate according to claim 41, wherein the diameter of the pores is the largest pore diameter of the porous silicon layer.
Claim 64
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 41, wherein the insulation layer is formed on the first member.
Claim 65
Dependent Claim
29 words
The process for producing a semiconductor substrate according to claim 61, wherein the insulation layer is formed by thermal oxidation of the surface of the nonporous monocrystalline silicon layer.
Claim 66
Dependent Claim
22 words
The process for producing a semiconductor substrate according to claim 61 or 62, wherein the second member is a monocrystalline silicon substrate.
Claim 67
Dependent Claim
25 words
The process for producing a semiconductor substrate according to claim 63, wherein the oxide layer is formed on the lamination face of the second member.
Claim 68
Dependent Claim
24 words
The process for producing a semiconductor substrate according to claim 63, wherein the lamination face of the second member is constituted of monocrystalline silicon.
Claim 69
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 61 or 62, wherein the second member is made of glass.
Claim 70
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 41, wherein the insulation layer is formed on the second member.
Claim 71
Dependent Claim
25 words
The process for producing a semiconductor substrate according to claim 67, wherein the insulation layer is formed by thermal oxidation of the monocrystalline silicon substrate.
Claim 72
Dependent Claim
19 words
The process for producing a semiconductor substrate according to claim 67, wherein the insulation layer constitutes a glass substrate.
Claim 73
Dependent Claim
28 words
The process for producing a semiconductor substrate according to any of claims 67 to 69, wherein the lamination face of the first member comprises nonporous monocrystalline silicon layer.
Claim 74
Dependent Claim
141 words
A process for producing a semiconductor substrate comprising: providing a first substrate having a porous silicon layer and a nonporous monocrystalline silicon layer grown thereon; laminating the nonporous monocrystalline silicon layer of the first substrate onto a second substrate with interposition of an insulation layer provided on at least one lamination face of the first substrate and the second substrate; and removing the porous silicon layer, wherein the step of growing the nonporous monocrystalline silicon layer is conducted (i) at a first growth rate controlled such that the density of remaining pores on the crystal growth face is less than 1000/cm 2 at the time when a monocrystalline silicon layer has grown to a thickness corresponding to the diameter of the pores of the porous monocrystalline silicon layer, and (ii) thereafter at a higher growth rate than said first growth rate.
Claim 75
Dependent Claim
141 words
A process for producing a semiconductor substrate comprising: providing a first substrate having a porous silicon layer and a nonporous monocrystalline silicon layer grown thereon; laminating the nonporous monocrystalline silicon layer of the first substrate onto a second substrate with interposition of an insulation layer provided on at least one lamination face of the first substrate and the second substrate; and removing the porous silicon layer, wherein the step of growing the nonporous monocrystalline silicon layer is conducted (i) at a first growth rate controlled such that the density of remaining pores on the crystal growth face is less than 1000/cm 2 at the time when a monocrystalline silicon layer has grown to a thickness corresponding to the diameter of the pores of the porous monocrystalline silicon layer, and (ii) thereafter at a higher growth rate than said first growth rate.
Claim 76
Dependent Claim
25 words
The process for producing a semiconductor substrate according to claim 41 or 71, wherein said removing the porous silicon layer is carried out by etching.
Claim 77
Dependent Claim
31 words
The process for producing a semiconductor substrate according to claim 1 or 41, wherein said silicon source gas is selected from the group consisting of silane dichlorosilane, trichlorosilane, tetrachlorosilane, and disilane.
Claim 78
Dependent Claim
110 words
A process for producing a semiconductor substrate comprising: providing a first substrate having a porous silicon layer and a nonporous monocrystalline silicon layer grown thereon; laminating the nonporous silicon layer of the first substrate onto a second substrate; and removing the porous silicon layer, wherein the nonporous monocrystalline silicon layer is grown in an atmosphere containing at least silicon source gas and hydrogen gas at a growth rate controlled such that the density of remaining pores on the crystal growth face is less than 1000/cm 2 at the time when a silicon layer has grown to a thickness corresponding to the diameter of the pores of the porous silicon layer.
Claim 79
Dependent Claim
110 words
A process for producing a semiconductor substrate comprising: providing a first substrate having a porous silicon layer and a nonporous monocrystalline silicon layer grown thereon; laminating the nonporous silicon layer of the first substrate onto a second substrate; and removing the porous silicon layer, wherein the nonporous monocrystalline silicon layer is grown in an atmosphere containing at least silicon source gas and hydrogen gas at a growth rate controlled such that the density of remaining pores on the crystal growth face is less than 1000/cm 2 at the time when a silicon layer has grown to a thickness corresponding to the diameter of the pores of the porous silicon layer.
Claim 80
Dependent Claim
120 words
A process for producing a semiconductor substrate comprising: providing a first substrate having a porous silicon layer and a nonporous monocrystalline silicon layer grown thereon; laminating the nonporous monocrystalline silicon layer of the first substrate onto a second substrate, and removing the porous silicon layer, wherein the step of growing the nonporous monocrystalline silicon layer is conducted (i) at a first growth rate controlled such that the density of remaining pores on the crystal growth face is less than 1000/cm 2 at the time when a monocrystalline silicon layer has grown to a thickness corresponding to the diameter of the pores of the porous monocrystalline silicon layer, and (ii) thereafter at a higher growth rate than said first growth rate.
Claim 81
Dependent Claim
120 words
A process for producing a semiconductor substrate comprising: providing a first substrate having a porous silicon layer and a nonporous monocrystalline silicon layer grown thereon; laminating the nonporous monocrystalline silicon layer of the first substrate onto a second substrate, and removing the porous silicon layer, wherein the step of growing the nonporous monocrystalline silicon layer is conducted (i) at a first growth rate controlled such that the density of remaining pores on the crystal growth face is less than 1000/cm 2 at the time when a monocrystalline silicon layer has grown to a thickness corresponding to the diameter of the pores of the porous monocrystalline silicon layer, and (ii) thereafter at a higher growth rate than said first growth rate.
Claim 82
Dependent Claim
43 words
The process for producing a semiconductor substrate according to claim 74 or 75, wherein a temperature of said porous silicon layer is 900° C. or more but not exceeding the melting point of silicon during the growth of the nonporous monocrystalline silicon layer.
Claim 83
Dependent Claim
27 words
The process for producing a semiconductor substrate according to claim 74 or 75, wherein said second substrate is a silicon substrate, quartz glass or blue plate glass.
Claim 84
Dependent Claim
41 words
The process for producing semiconductor substrate according to claim 74 or 75, which process further includes a step of forming a protecting film on a pore wall of said porous silicon layer prior to the growth of said monocrystalline silicon layer.
Claim 85
Dependent Claim
42 words
The process for producing a semiconductor substrate according to claim 74 or 75, which process further includes a step of removing an oxide film on an external surface of said porous silicon layer prior to the growth of said monocrystalline silicon layer.
Claim 86
Dependent Claim
39 words
The process for producing a semiconductor substrate according to claim 74 or 75, which process further includes a step of heat-treating said porous silicon layer in an atmosphere containing hydrogen prior to the growth of said monocrystalline silicon layer.
Claim 87
Dependent Claim
56 words
The process for producing a semiconductor substrate according to claim 74 or 75 which process further includes a step of forming a protecting film on a pore wall of said porous silicon layer and removing an oxide film on an external surface of said porous silicon layer, prior to the growth of said monocrystalline silicon layer.
Claim 88
Dependent Claim
66 words
The process for producing a semiconductor substrate according to claim 74 or 75, which process further includes a step of forming a protecting film on a pore wall of said porous silicon layer, removing an oxide film on an external surface of said porous silicon layer, and heat-treating said porous silicon layer in an atmosphere containing hydrogen, prior to the growth of said monocrystalline silicon layer.
Claim 89
Dependent Claim
61 words
A process for producing a semiconductor substrate having a porous silicon layer and a nonporous monocrystalline silicon layer thereon, which comprises: providing a substrate having a porous silicon layer; and growing a monocrystalline silicon layer on said porous silicon layer in an atmosphere containing at least silicon source gas and hydrogen gas at a growth rate of 20 nm/min or less.
Claim 90
Dependent Claim
61 words
A process for producing a semiconductor substrate having a porous silicon layer and a nonporous monocrystalline silicon layer thereon, which comprises: providing a substrate having a porous silicon layer; and growing a monocrystalline silicon layer on said porous silicon layer in an atmosphere containing at least silicon source gas and hydrogen gas at a growth rate of 20 nm/min or less.
Claim 91
Dependent Claim
69 words
A process for producing a semiconductor substrate having a porous silicon layer and a nonporous monocrystalline silicon layer thereon, which comprises: providing a substrate having a porous silicon layer; growing a monocrystalline silicon layer on said porous silicon layer at a growth rate of 20 nm/min or less; and growing a monocrystalline silicon layer at an increased growth rate larger than said growth rate of 20 nm/min or less.
Claim 92
Dependent Claim
69 words
A process for producing a semiconductor substrate having a porous silicon layer and a nonporous monocrystalline silicon layer thereon, which comprises: providing a substrate having a porous silicon layer; growing a monocrystalline silicon layer on said porous silicon layer at a growth rate of 20 nm/min or less; and growing a monocrystalline silicon layer at an increased growth rate larger than said growth rate of 20 nm/min or less.
Claim 93
Dependent Claim
72 words
A process for producing a semiconductor substrate which comprises: providing a first substrate having a porous silicon layer; growing a monocrystalline silicon layer on said porous silicon layer in an atmosphere containing at least silicon source gas and hydrogen gas at a growth rate of 20 nm/min or less; bonding said first substrate to a second substrate such that said monocrystalline silicon layer is positioned inside; and removing said porous silicon layer.
Claim 94
Dependent Claim
72 words
A process for producing a semiconductor substrate which comprises: providing a first substrate having a porous silicon layer; growing a monocrystalline silicon layer on said porous silicon layer in an atmosphere containing at least silicon source gas and hydrogen gas at a growth rate of 20 nm/min or less; bonding said first substrate to a second substrate such that said monocrystalline silicon layer is positioned inside; and removing said porous silicon layer.
Claim 95
Dependent Claim
80 words
A process for producing a semiconductor substrate which comprises: providing a first substrate having a porous silicon layer; growing a monocrystalline silicon layer on said porous silicon layer at a growth rate of 20 nm/min or less; growing a monocrystalline silicon layer at an increased growth rate larger than said growth rate of 20 nm/min or less; bonding said first substrate to a second substrate such that said monocrystalline silicon layer is positioned inside; and removing said porous silicon layer.
Claim 96
Dependent Claim
80 words
A process for producing a semiconductor substrate which comprises: providing a first substrate having a porous silicon layer; growing a monocrystalline silicon layer on said porous silicon layer at a growth rate of 20 nm/min or less; growing a monocrystalline silicon layer at an increased growth rate larger than said growth rate of 20 nm/min or less; bonding said first substrate to a second substrate such that said monocrystalline silicon layer is positioned inside; and removing said porous silicon layer.
Claim 97
Dependent Claim
24 words
The process for producing a semiconductor substrate according to claim 85 or 86, including providing an insulating layer between said first and second substrates.
Claim 98
Dependent Claim
51 words
The process for producing a semiconductor substrate according to any of claims 83 through 86, including controlling a temperature of said porous silicon layer to be 900° C. or more, but not exceeding the melting point of the porous silicon layer, during the step of growing the nonporous monocrystalline silicon layer.
Claim 99
Dependent Claim
45 words
The process for producing a semiconductor substrate according to any of claims 83 through 86, which process further includes a step of forming a protective film on a pore wall of said porous monocrystalline silicon layer prior to the growth of said monocrystalline silicon layer.
Claim 100
Dependent Claim
45 words
The process for producing a semiconductor substrate according to any of claims 83 through 86, which process further includes a step of removing an oxide film on an external surface of said porous monocrystalline silicon layer prior to the growth of said monocrystalline silicon layer.
Claim 101
Dependent Claim
54 words
The process for producing a semiconductor substrate according to any of claims 83 through 86, which process further includes a step of heat-treating said porous monocrystalline silicon layer in a reducing atmosphere containing at least hydrogen or nitrogen, or in an atmosphere of inert gas, prior to the growth of said monocrystalline silicon layer.
Claim 102
Dependent Claim
58 words
The process for producing a semiconductor substrate according to any of claims 83 through 86, which process further includes a step of forming a protective film on a pore wall of said porous silicon layer and removing an oxide film on an external surface of said porous silicon layer, prior to the growth of said monocrystalline silicon layer.
Claim 103
Dependent Claim
55 words
The process for producing a semiconductor substrate according to any of claims 83 through 86, which process further includes the steps of forming a protective film on a pore wall of said porous silicon layer, and heat-treating said porous silicon layer in an atmosphere containing hydrogen, prior to the growth of said monocrystalline silicon layer.
Claim 104
Dependent Claim
32 words
The process for producing a semiconductor substrate according to claims 74, 83, and 85, wherein said silicon source gas is selected from a group consisting of silane, dichlorosilane, trichlorosilane, tetrachlorosilane and disilane.
Claim 105
Dependent Claim
41 words
The process for producing a semiconductor substrate according to claims 1, 21, 41, 71, 74 or 75, wherein said density of remaining pores is measured by a gas adsorption method or an observation by means of ultrahigh resolution scanning electron microscopy.
Claim 106
Dependent Claim
73 words
The process for producing a semiconductor substrate according to claims 21, 71, 75, 84 or 86, wherein silane (SiH 4 ) is used as a silicon source gas when said nonporous monocrystalline silicon layer is grown at said first growth rate, and dichlorosilane (SiH 2 Cl 2 ) is used as a silicon source gas when said nonporous monocrystalline silicon layer is grown at a higher growth rate than said first growth rate.
Claim 107
Dependent Claim
74 words
The process for producing a semiconductor substrate according to claims 21, 71, 75, 84 or 86, wherein dichlorosilane (SiH 2 Cl 2 ) is used as a silicon source gas when said nonporous monocrystalline silicon layer is grown at said first growth rate, and dichlorosilane (SiH 2 Cl 2 ) is used as a source gas when said nonporous monocrystalline silicon layer is grown at a higher growth rate than said first growth rate.
Claim 108
Dependent Claim
71 words
The process for producing a semiconductor substrate according to claims 21, 71, 75, 84 or 86, wherein silane (SiH 4 ) is used as a silicon source gas when said nonporous monocrystalline silicon layer is grown at said first growth rate, and silane (SiH 4 ) is used as a silicon source gas when said nonporous monocrystalline silicon layer is grown at a higher growth rate than said first growth rate.
Claim 109
Dependent Claim
25 words
The process for producing a semiconductor substrate according to claims 83, 84, 85 or 86, wherein said growth rate is not more than 10 nm/min.
Claim 110
Dependent Claim
25 words
The process for producing a semiconductor substrate according to claims 83, 84, 85 or 86, wherein said growth rate is not more than 2 nm/min.
Claim 111
Dependent Claim
41 words
The process for producing a semiconductor substrate according to claims 1, 21, 41, 71, 74, 75, 83, 84, 85 or 86, wherein said growing of said nonporous monocrystalline silicon layer is carried out under a pressure of 10 to 760 Torr.
Claim 112
Dependent Claim
42 words
The process for producing a semiconductor substrate according to claims 1, 21, 41, 71, 74, 75, 83, 84, 85 or 86, wherein said growing of said nonporous monocrystalline silicon layer is carried out at a temperature of not lower than 800° C.
Claim 113
Dependent Claim
69 words
The process for producing a semiconductor substrate according to claims 1, 21, 41, 71, 74, 75, 83, 84, 85 or 86, wherein prior to said growing of said nonporous monocrystalline silicon layer said porous silicon layer is heat-treated under an atmosphere containing hydrogen, and said heat-treating under the atmosphere containing hydrogen and said growing of the nonporous monocrystalline silicon layer are conducted successively in a same CVD growth furnace.
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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) | 2003-10-24 | 2004-04-24 | 2004-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-10-24 | 2008-04-24 | 2008-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-10-24 | 2012-04-24 | 2012-10-24 | $7700.00 | Window Closed / Lapsed |