Patent EP0755068A2 successfully refreshed from Google Patents.
EP0755068A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Semiconductor substrate and process for production thereof
Assignee: Canon Inc
•
Filing: 1996-07-19
•
Granted: —
•
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/cm 2 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
EP
Data Source
google_patents
Last Synchronized
2026-11-04 23:06
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: 33
Claim 1
Independent Claim
80 words
A process for producing a semiconductor substrate having a porous monocrystalline silicon layer and a nonporous monocrystalline silicon layer grown thereon, 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/cm 2 at the time when the nonporous monocrystalline silicon layer has grown to a thickness corresponding to the diameter of the pores of the porous monocrystalline silicon layer.
Claim 2
Dependent Claim
95 words
A process for producing a semiconductor substrate having a porous monocrystalline silicon layer and a nonporous monocrystalline silicon layer grown thereon, wherein the nonporous monocrystalline silicon layer is grown firstly at a low growth rate controlled such that the density of remaining pores on the crystal growth face is not more than 1000/cm 2 at the time when the nonporous monocrystalline silicon layer has grown to a thickness corresponding to the diameter of the pores of the porous monocrystalline silicon layer, and thereafter the nonporous monocrystalline silicon layer is grown at an increased growth rate.
Claim 3
Dependent Claim
127 words
A process for producing a semiconductor substrate comprising 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/cm 2 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.
Claim 4
Dependent Claim
39 words
The process for producing a semiconductor substrate according to any of claims 1 to 3, 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 5
Dependent Claim
24 words
The process for producing a semiconductor substrate according to claim 4, wherein the source gas is selected from silane, dichlorosilane, trichlorosilane, tetrachlorosilane, and disilane.
Claim 6
Dependent Claim
37 words
The process for producing a semiconductor substrate according to any of claims 1 to 5, wherein the porous monocrystalline silicon layer is heated in a nonoxidative atmosphere prior to the growth of the nonporous monocrystalline silicon layer.
Claim 7
Dependent Claim
19 words
The process for producing a semiconductor substrate according to claim 6, wherein the nonoxidative atmosphere is a hydrogen atmosphere.
Claim 8
Dependent Claim
39 words
The process for producing a semiconductor substrate according to any of claims 4 to 7, wherein the porous monocrystalline silicon layer is heated to a temperature of 900°C or higher during the growth of the nonporous monocrystalline silicon layer.
Claim 9
Dependent Claim
37 words
The process for producing a semiconductor substrate according to any of claims 1 to 8, wherein the process comprises a step of removing a natural oxide film prior to the growth of the nonporous monocrystalline silicon layer.
Claim 10
Dependent Claim
59 words
The process for producing a semiconductor substrate according to any of claims 1 to 5, wherein the process comprises steps of forming an ultrathin film on a wall of the porous monocrystalline silicon layer, and removing the oxide film on the external surface of the porous monocrystalline silicon layer prior to the growth of the nonporous monocrystalline silicon layer.
Claim 11
Dependent Claim
68 words
The process for producing a semiconductor substrate according to any of claims 1 to 5, wherein the process comprises steps of forming an ultrathin film on a wall of the porous monocrystalline silicon layer, removing the oxide film on the surface of the porous monocrystalline silicon layer, and heat-treating the porous monocrystalline silicon layer in a hydrogen atmosphere prior to the growth of the nonporous monocrystalline silicon layer.
Claim 12
Dependent Claim
25 words
The process for producing a semiconductor substrate according to any of claims 1 to 11, wherein the growth rate is not higher than 20 nm/min.
Claim 13
Dependent Claim
32 words
The process for producing a semiconductor substrate according to any preceding claim 1 to 12, wherein the diameter of the pores is the largest pore diameter of the porous monocrystalline silicon layer.
Claim 14
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 3, wherein the insulation layer is formed on the first member.
Claim 15
Dependent Claim
29 words
The process for producing a semiconductor substrate according to claim 14, wherein the insulation layer is formed by thermal oxidation of the surface of the nonporous monocrystalline silicon layer.
Claim 16
Dependent Claim
23 words
The process for producing a semiconductor substrate according to either claim 14 or 15, wherein the second member is a monocrystalline silicon substrate.
Claim 17
Dependent Claim
25 words
The process for producing a semiconductor substrate according to claim 16, wherein the oxide layer is formed on the lamination face of the second member.
Claim 18
Dependent Claim
24 words
The process for producing a semiconductor substrate according to claim 16, wherein the lamination face of the second member is constituted of monocrystalline silicon.
Claim 19
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 14 or 15, wherein the second member is made of glass.
Claim 20
Dependent Claim
21 words
The process for producing a semiconductor substrate according to claim 3, wherein the insulation layer is formed on the second member.
Claim 21
Dependent Claim
25 words
The process for producing a semiconductor substrate according to claim 20, wherein the insulation layer is formed by thermal oxidation of the monocrystalline silicon substrate.
Claim 22
Dependent Claim
19 words
The process for producing a semiconductor substrate according to claim 20, wherein the insulation layer constitutes a glass substrate.
Claim 23
Dependent Claim
28 words
The process for producing a semiconductor substrate according to any of claims 20 to 22, wherein the lamination face of the first member comprises nonporous monocrystalline silicon layer.
Claim 24
Dependent Claim
143 words
A process for producing a semiconductor substrate comprising providing a first member having a porous monocrystalline silicon layer and a nonporous monocrystalline silicon layer grown thereon, laminating the nonporous monocrystalline 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/cm 2 at the time when the nonporous monocrystalline silicon layer has grown to a thickness corresponding to the diameter of the pores of the porous monocrystalline silicon layer, and thereafter the nonporous monocrystalline silicon layer is grown at an increased growth rate.
Claim 25
Dependent Claim
34 words
A semiconductor substrate having a porous monocrystalline silicon layer and a nonporous monocrystalline silicon layer formed thereon, the nonporous monocrystalline silicon layer having crystal defects in a density of less than 1000/cm 2 .
Claim 26
Dependent Claim
23 words
The semiconductor substrate according to claim 25, wherein the nonporous monocrystalline silicon layer has a layer thickness uniformity in the range within ±4%.
Claim 27
Dependent Claim
16 words
The semiconductor substrate according to claim 25 or 26, wherein the crystal defects are lamination defects.
Claim 28
Dependent Claim
26 words
The semiconductor substrate according to any of claims 25 to 27, wherein the nonporous monocrystalline silicon layer has surface roughness of not more than 0.5 nm.
Claim 29
Dependent Claim
20 words
The semiconductor substrate according to any of claims 25 to 28, wherein the nonporous monocrystalline silicon layer has no pinhole.
Claim 30
Dependent Claim
23 words
The semiconductor substrate according to any of claims 25 to 29, wherein the nonporous monocrystalline silicon layer has a plane orientation of (001).
Claim 31
Dependent Claim
25 words
The semiconductor substrate according to any of claims 25 to 30, wherein the porous monocrystalline silicon layer has a porosity of not more than 50%.
Claim 32
Dependent Claim
39 words
A semiconductor substrate having an insulation layer and a nonporous monocrystalline silicon layer formed thereon, the nonporous monocrystalline silicon layer having crystal defects in a crystal defect density of less than 1000/cm 2 and layer thickness uniformity within ±4%.
Claim 33
Dependent Claim
14 words
An integrated circuit defined in any substrate as claimed in claims 25 to 32.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.