US6180497B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing semiconductor base members
Assignee: Canon Inc
•
Filing: 1999-07-21
•
Granted: 2001-01-30
•
Expires: 2019-07-21
Abstract
Abstract A method of producing a semiconductor base member that can be used as a Silicon on Insulator (SOI) wafer is presented. To produce an SOI wafer, it is necessary to prepare a base member having a porous layer upon which a non porous layer is formed. To make the pore size distribution of a porous layer uniform, a surface comprising atom steps and terraces is formed on the surface of a silicon base material and made porous without eliminating the steps and terraces, and then a nonporous semiconductor single-crystal film is formed thereon.
Inventors
- 👤 Nobuhiko Sato
- 👤 Satoshi Matsumura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:14
CPC Classifications
H; H10; H10P; H10P10/00; H10P90/00; H10P90/12; H10P90/15; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1914; H10P90/1924; H10W; H10W10/00; H10W10/10; H10W10/181; Y; Y10; Y10S; Y10S438/00; Y10S438/964
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
37 words
A method for producing a semiconductor base member, which comprises the steps of forming a surface comprising atom steps and terraces on a silicon base material, making the surface porous, and then forming a nonporous film thereon.
Claim 2
Independent Claim
37 words
A method for producing a semiconductor base member, which comprises the steps of forming a surface comprising atom steps and terraces on a silicon base material, making the surface porous, and then forming a nonporous film thereon.
Claim 3
Dependent Claim
57 words
The method for producing a semiconductor base member according to claim 1 , wherein the surface comprising atom steps and terraces is obtained by forming the atom steps and the terraces by a heat treatment in a hydrogen containing reducing atmosphere and then cleaning the surface under a condition of not eliminating the atom steps and terraces.
Claim 4
Dependent Claim
23 words
The method for producing a semiconductor base member according to claim 2 , wherein the hydrogen containing reducing atmosphere contains 100% of hydrogen.
Claim 5
Dependent Claim
53 words
The method for producing a semiconductor base member according to claim 1 , wherein the surface comprising atom steps and terraces is obtained by forming an epitaxial silicon layer to form the atom steps and the terraces and then cleaning the surface under a condition of not eliminating the atom steps and terraces.
Claim 6
Dependent Claim
34 words
The method for producing a semiconductor base member according to claim 4 , wherein the epitaxial silicon layer is doped with an impurity to be converted to a p- or an n-type degenerate state.
Claim 7
Dependent Claim
67 words
The method for producing a semiconductor base member according to claim 1 , wherein a silicon base material having a surface without atom steps and terraces is provided, the atom steps and terraces are formed on the surface, the surface is cleaned under a condition of not eliminating the atom steps and terraces, and the cleaned surface comprising the atom steps and the terraces is made porous.
Claim 8
Dependent Claim
36 words
The method for producing a semiconductor base member according to claim 1 , wherein the surface comprising steps and terraces is obtained by forming the atom steps and the terraces by chemical cleaning or gas etching.
Claim 9
Dependent Claim
85 words
The method for producing a semiconductor base member according to claim 1 , wherein an epitaxial silicon layer having an impurity concentration larger than that of the provided silicon base material is formed on the provided silicon base material to form the atom steps and terraces, the surface comprising the atom steps and the terraces is cleaned under a condition of not eliminating the atom steps and terraces, and then the epitaxial silicon layer and the surface of the silicon base material are made porous.
Claim 10
Dependent Claim
25 words
The method for producing a semiconductor base member according to claim 1 , wherein the cycle of the atom steps is 200 nm or more.
Claim 11
Dependent Claim
46 words
The method for producing a semiconductor base member according to claim 1 , further comprising the step of epitaxially growing the silicon base material containing an impurity and then thermally treating the base material to diffuse the impurity from the base material to the epitaxial layer.
Claim 12
Independent Claim
87 words
A method for producing a semiconductor base member, which comprises: the step of forming a surface comprising atom steps and terraces on a silicon base material, making the surface porous to form a porous layer, and forming a nonporous semiconductor single-crystal film thereon to provide a first member; the step of bonding the first member and a second member together so as to obtain a multilayer structure with the nonporous semiconductor single-crystal film positioned inside; and the step of removing the porous layer from the multilayer structure.
Claim 13
Independent Claim
87 words
A method for producing a semiconductor base member, which comprises: the step of forming a surface comprising atom steps and terraces on a silicon base material, making the surface porous to form a porous layer, and forming a nonporous semiconductor single-crystal film thereon to provide a first member; the step of bonding the first member and a second member together so as to obtain a multilayer structure with the nonporous semiconductor single-crystal film positioned inside; and the step of removing the porous layer from the multilayer structure.
Claim 14
Dependent Claim
57 words
The method for producing a semiconductor base member according to claim 11 , wherein the surface comprising atom steps and terraces is obtained by forming the atom steps and the terraces by a heat treatment in a hydrogen containing reducing atmosphere and then cleaning the surface under a condition of not eliminating the atom steps and terraces.
Claim 15
Dependent Claim
23 words
The method for producing a semiconductor base member according to claim 12 , wherein the hydrogen containing reducing atmosphere contains 100% of hydrogen.
Claim 16
Dependent Claim
53 words
The method for producing a semiconductor base member according to claim 11 , wherein the surface comprising atom steps and terraces is obtained by forming an epitaxial silicon layer to form the atom steps and the terraces and then cleaning the surface under a condition of not eliminating the atom steps and terraces.
Claim 17
Dependent Claim
34 words
The method for producing a semiconductor base member according to claim 14 , wherein the epitaxial silicon layer is doped with an impurity to be converted to a p- or an n-type degenerate state.
Claim 18
Dependent Claim
67 words
The method for producing a semiconductor base member according to claim 11 , wherein a silicon base material having a surface without atom steps and terraces is provided, the atom steps and terraces are formed on the surface, the surface is cleaned under a condition of not eliminating the atom steps and terraces, and the cleaned surface comprising the atom steps and the terraces is made porous.
Claim 19
Dependent Claim
36 words
The method for producing a semiconductor base member according to claim 11 , wherein the surface comprising steps and terraces is obtained by forming the atom steps and the terraces by chemical cleaning or gas etching.
Claim 20
Dependent Claim
83 words
The method for producing a semiconductor base member according to claim 11 , wherein an epitaxial silicon layer having an impurity concentration larger than that of the provided silicon base material is formed on the provided silicon base material to form atom steps and terraces, the surface comprising the atom steps and terraces is cleaned under a condition of not eliminating the atom steps and terraces, and then the epitaxial silicon layer and the surface of the silicon base material are made porous.
Claim 21
Dependent Claim
25 words
The method for producing a semiconductor base member according to claim 11 , wherein an interval between the atom steps is 200 nm or more.
Claim 22
Dependent Claim
52 words
The method for producing a semiconductor base member according to claim 11 , further comprising the step of growing an epitaxial layer on the surface of the silicon base material containing an impurity and then thermally treating the surface to diffuse the impurity from the silicon base material to the epitaxial layer.
Claim 23
Dependent Claim
35 words
The method for producing a semiconductor base member according to claim 11 , wherein an insulating film is formed on a surface to be bonded of at least one of the first and second members.
Claim 24
Dependent Claim
20 words
The method for producing a semiconductor base member according to claim 11 , wherein the second member is an insulator.
Claim 25
Dependent Claim
44 words
The method for producing a semiconductor base member according to claim 11 , wherein the step of removing the porous layer from the multilayer structure is carried out by removing the silicon base material not made porous and then removing the exposed porous layer.
Claim 26
Dependent Claim
32 words
The method for producing a semiconductor base member according to claim 23 , wherein the silicon base material not made porous is removed by at least one of grinding, polishing, and etching.
Claim 27
Dependent Claim
40 words
The method for producing a semiconductor base member according to claim 23 , wherein the multilayer structure is separated inside the porous layer and/or on an interface with the porous layer to remove the silicon base material not made porous.
Claim 28
Dependent Claim
22 words
The method for producing a semiconductor base member according to claim 11 , wherein the entire silicon base material is made porous.
Claim 29
Dependent Claim
110 words
The method for producing a semiconductor base member according to claim 11 , wherein the surface comprising atom steps and terraces is formed by depositing a p + epitaxial silicon layer on a p − or an n − silicon region or by depositing an n + epitaxial silicon layer on an n − silicon region, wherein the porous layer is formed so as to enter at least a part of the p − or n − silicon region, and wherein the multilayer structure is separated inside the porous layer in the p − or n − silicon region and/or on the interface between the region and the porous layer.
Claim 30
Dependent Claim
36 words
The method for producing a semiconductor base member according to claim 11 , wherein the silicon base material separated in the separation step is used again as the silicon base material for the first member again.
Claim 31
Dependent Claim
24 words
The method for producing a semiconductor base member according to claim 11 , wherein the silicon base material is a dummy grade silicon wafer.
Claim 32
Dependent Claim
49 words
The method for producing a semiconductor base member according to claim 11 , wherein after making porous the surface of the silicon base material comprising atom steps and terraces, a heat treatment in a hydrogen containing reducing atmosphere is executed to seal the pores of the surface made porous.
Claim 33
Dependent Claim
51 words
The method for producing a semiconductor base member according to claim 11 , wherein after making porous the surface of the silicon base material comprising atom steps and terraces, the surfaces of the side walls of the pores in the porous silicon and the surface of the porous silicon are oxidized.
Claim 34
Dependent Claim
73 words
The method for producing a semiconductor base member according to claim 11 , wherein after making porous the surface of the silicon base material comprising atom steps and terraces, the surface of the side walls of the pores of the porous silicon and the surface of the porous silicon are oxidized, and then a heat treatment in a hydrogen containing reducing atmosphere is executed to seal the pores of the surface made porous.
Claim 35
Dependent Claim
49 words
The method for producing a semiconductor base member according to claim 11 , wherein after oxidizing the surfaces of the side walls of the pores of the porous silicon and the surface of the porous silicon, an oxide film is peeled off from the surface of the porous silicon.
Claim 36
Dependent Claim
21 words
The method for producing a semiconductor base member according to claim 1 , wherein the nonporous semiconductor single-crystal film comprises silicon.
Claim 37
Dependent Claim
21 words
The method for producing a semiconductor base member according to claim 11 , wherein the nonporous semiconductor single-crystal film comprises silicon.
Claim 38
Dependent Claim
21 words
The method for producing a semiconductor base member according to claim 1 , wherein the silicon base material is single-crystal silicon.
Claim 39
Dependent Claim
21 words
The method for producing a semiconductor base member according to claim 11 , wherein the silicon base material is single-crystal silicon.
Claim 40
Dependent Claim
22 words
The method for producing a semiconductor base member according to claim 1 , wherein the silicon base material is (100) single-crystal silicon.
Claim 41
Dependent Claim
22 words
The method for producing a semiconductor base member according to claim 11 , wherein the silicon base material is (100) single-crystal silicon.
References Cited (Backward Citations)
JPH0521338A
Cited
US5371037A
Cited
US5869387A
Cited
US5856229A
Cited
JPH09102594A
Cited
US6100166A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-01-30 | 2004-07-31 | 2005-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-01-30 | 2008-07-31 | 2009-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-01-30 | 2012-07-31 | 2013-01-30 | $7700.00 | Window Closed / Lapsed |