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EP0975012A2
Expired / Lapsed
EP
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Porous silicon with uniform pore size distribution
Assignee: Canon Inc
•
Filing: 1999-07-22
•
Granted: —
•
Expires: 2019-07-22
Abstract
Abstract 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
EP
Data Source
google_patents
Last Synchronized
2026-11-07 03:37
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: 38
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
Dependent Claim
56 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 3
Dependent Claim
22 words
The method for producing a semiconductor base
member according to claim 2, wherein the hydrogen
containing reducing atmosphere contains 100% of
hydrogen.
Claim 4
Dependent Claim
52 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 5
Dependent Claim
33 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 6
Dependent Claim
66 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 7
Dependent Claim
35 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 8
Dependent Claim
84 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 9
Dependent Claim
24 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 10
Dependent Claim
45 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 11
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 12
Dependent Claim
56 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 13
Dependent Claim
22 words
The method for producing a semiconductor base
member according to claim 12, wherein the hydrogen
containing reducing atmosphere contains 100% of
hydrogen.
Claim 14
Dependent Claim
52 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 15
Dependent Claim
33 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 16
Dependent Claim
66 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 17
Dependent Claim
35 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 18
Dependent Claim
82 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 19
Dependent Claim
24 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 20
Dependent Claim
51 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 21
Dependent Claim
34 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 22
Dependent Claim
19 words
The method for producing a semiconductor base
member according to claim 11, wherein the second member
is an insulator.
Claim 23
Dependent Claim
43 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 24
Dependent Claim
31 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 25
Dependent Claim
39 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 26
Dependent Claim
21 words
The method for producing a semiconductor base
member according to claim 11, wherein the entire
silicon base material is made porous.
Claim 27
Dependent Claim
109 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 28
Dependent Claim
35 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 29
Dependent Claim
23 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 30
Dependent Claim
48 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 31
Dependent Claim
50 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 32
Dependent Claim
72 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 33
Dependent Claim
48 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 34
Dependent Claim
22 words
The method for producing a semiconductor base
member according to claim 1 or 11, wherein the
nonporous semiconductor single-crystal film comprises
silicon.
Claim 35
Dependent Claim
22 words
The method for producing a semiconductor base
member according to claim 1 or 11, wherein the silicon
base material is single-crystal silicon.
Claim 36
Dependent Claim
23 words
The method for producing a semiconductor base
member according to claim 1 or 11, wherein the silicon
base material is (100) single-crystal silicon.
Claim 37
Dependent Claim
25 words
A semiconductor base member produced by means
of a method for producing a semiconductor base member
according to any one of claims 1 to 36.
Claim 38
Dependent Claim
66 words
A method of producing a semiconductor device comprising
steps of: producing a semiconductor base member by the method of any
of claims 11 to 33 or of any of claims 34 to 36 depending from
claim 11; and processing the semiconductor base member to form a
semiconductor device having respective parts formed in and upon the
non-porous semiconductor single crystal film of said semiconductor
base member.
References Cited (Backward Citations)
No citation records indexed.
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