US6375738B1
Expired / Lapsed
US
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Process of producing semiconductor article
Assignee: Canon Inc
•
Filing: 2000-03-24
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Granted: 2002-04-23
•
Expires: 2020-03-24
Abstract
Abstract A process of producing a semiconductor article is disclosed which comprises the steps of epitaxially growing on at least one surface of a single-crystal substrate a plurality of single-crystal semiconductor layers differing from each other in at least one of the kind and the concentration of an impurity, making porous the plurality of single-crystal semiconductor layers so as to form a high porosity layer and a low porosity layer, forming a non-porous single-crystal layer on a surface of the single-crystal semiconductor layer as made porous, and bonding and single-crystal substrate and a support substrate to each other, wherein the bonded single-crystal substrate and support substrate are separated at at least one of a location in the high porosity layer and an interface of the high porosity layer with a layer adjacent thereto.
Inventors
- 👤 Nobuhiko Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:51
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1924; H10W; H10W10/00; H10W10/10; H10W10/181; H10P50/00; Y; Y10; Y10S; Y10S117/00; Y10S117/915
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
155 words
A process of producing a semiconductor article comprising the steps of: epitaxially growing on at least one surface of a single-crystal substrate a plurality of single-crystal semiconductor layers comprising a first single-crystal semiconductor layer and a second single-crystal semiconductor layer and differing from each other in at least one of the kind and the concentration of an impurity; making porous the plurality of single-crystal semiconductor layers so as to form a high porosity layer in the first single-crystal semiconductor layer and a low porosity layer in the second single-crystal semiconductor layer; subsequently forming a non-porous single-crystal layer on a surface of the single-crystal semiconductor layers as made porous; and bonding the single-crystal substrate and a support substrate to each other, wherein the bonded single-crystal substrate and support substrate are separated at at least one of a location in the high porosity layer and an interface of the high porosity layer with a layer adjacent thereto.
Claim 2
Dependent Claim
155 words
A process of producing a semiconductor article comprising the steps of: epitaxially growing on at least one surface of a single-crystal substrate a plurality of single-crystal semiconductor layers comprising a first single-crystal semiconductor layer and a second single-crystal semiconductor layer and differing from each other in at least one of the kind and the concentration of an impurity; making porous the plurality of single-crystal semiconductor layers so as to form a high porosity layer in the first single-crystal semiconductor layer and a low porosity layer in the second single-crystal semiconductor layer; subsequently forming a non-porous single-crystal layer on a surface of the single-crystal semiconductor layers as made porous; and bonding the single-crystal substrate and a support substrate to each other, wherein the bonded single-crystal substrate and support substrate are separated at at least one of a location in the high porosity layer and an interface of the high porosity layer with a layer adjacent thereto.
Claim 3
Dependent Claim
55 words
The process according to claim 1 , wherein a plurality of single-crystal semiconductor layers differing from each other in at least one of the kind and the concentration of an impurity are again epitaxially grown on the single-crystal substrate obtained by removing the high porosity layer remaining on the side of the separated single-crystal substrate.
Claim 4
Dependent Claim
15 words
The process according to claim 1 , wherein the single-crystal substrate is a semiconductor substrate.
Claim 5
Dependent Claim
15 words
The process according to claim 3 , wherein the semiconductor substrate is a silicon substrate.
Claim 6
Dependent Claim
34 words
The process according to claim 1 , wherein the low porosity layer is formed in the surface of the single-crystal semiconductor layer and the high porosity layer is formed under the low porosity layer.
Claim 7
Dependent Claim
20 words
The process according to claim 5 , wherein the thickness of the low porosity layer is 20 μm or less.
Claim 8
Dependent Claim
28 words
The process according to claim 1 , wherein a low impurity concentration layer is formed on the single-crystal substrate and a high impurity concentration layer is formed thereon.
Claim 9
Dependent Claim
36 words
The process according to claim 1 , wherein the resistivity ρ 1 of the low porosity layer and the resistivity ρ 2 of the high porosity layer satisfy the relationship of ρ 1 <ρ 2 .
Claim 10
Dependent Claim
23 words
The process according to claim 8 , wherein the resistivity ρ 1 of the low porosity layer satisfies 0.001 Ωcm<ρ 1 ≦0.1 Ωcm.
Claim 11
Dependent Claim
23 words
The process according to claim 8 , wherein the resistivity ρ 1 of the low porosity layer satisfies 0.005 Ωcm<ρ 1 ≦0.02 Ωcm.
Claim 12
Dependent Claim
23 words
The process according to claim 8 , wherein the resistivity ρ 2 of the high porosity layer satisfies 0.02 Ωcm<ρ 2 ≦10000 Ωcm.
Claim 13
Dependent Claim
23 words
The process according to claim 8 , wherein the resistivity ρ 2 of the high porosity layer satisfies 0.1 Ωcm<ρ 2 ≦100 Ωcm.
Claim 14
Dependent Claim
21 words
The process according to claim 1 or 2 , wherein the separated single-crystal substrate is subjected to smoothing to be reutilized.
Claim 15
Dependent Claim
23 words
The process according to claim 13 , wherein the smoothing is carried out after the step of removing the remaining high porosity layer.
Claim 16
Dependent Claim
20 words
The process according to claim 14 , wherein the smoothing is a heat treatment in a reducing atmosphere comprising hydrogen.
Claim 17
Dependent Claim
18 words
The process according to claim 1 , wherein the single-crystal semiconductor substrate is grown by chemical vapor deposition.
Claim 18
Dependent Claim
29 words
The process according to claim 1 , wherein the bonding step comprises bonding the non-porous single-crystal layer and the support substrate to each other with an insulating layer therebetween.
Claim 19
Dependent Claim
16 words
The process according to claim 1 , wherein the non-porous single-crystal layer is a semiconductor layer.
Claim 20
Dependent Claim
15 words
The process according to claim 18 , wherein the semiconductor layer is a silicon layer.
Claim 21
Dependent Claim
26 words
The process according to claim 1 , wherein the single-crystal substrate and the support substrate are separated by applying an external force to the bonded substrate.
Claim 22
Dependent Claim
34 words
The process according to claim 1 , wherein the single-crystal substrate and the support substrate are separated by inserting into the bonded substrate at least one of a solid wedge and a fluid wedge.
Claim 23
Dependent Claim
26 words
The process according to claim 1 , wherein the single-crystal substrate and the support substrate are separated by generating an internal stress in the bonded substrate.
Claim 24
Dependent Claim
35 words
The process according to claim 1 , wherein the single-crystal substrate and the support substrate are separated by externally applying to the bonded substrate at least one of a thermal energy and an optical energy.
Claim 25
Dependent Claim
28 words
The process according to claim 1 , wherein the single-crystal substrate and the support substrate are separated by jetting a fluid to a recess of the bonded substrate.
Claim 26
Dependent Claim
33 words
The process according to claim 1 , wherein the single-crystal substrate and the support substrate are separated by attaching a jig to the bonded substrate and applying a mechanical force to the jig.
Claim 27
Dependent Claim
31 words
The process according to claim 1 , wherein the separated single-crystal substrate is reutilized and subjected to the processing of the respective steps of claim 1 to produce a semiconductor article.
Claim 28
Dependent Claim
25 words
The process according to claim 1 , wherein anodization is carried out such that the single-crystal semiconductor layer remains non-porous under the high porosity layer.
Claim 29
Dependent Claim
24 words
The process according to claim 1 , wherein the thickness of the low porosity layer is different from that of the high porosity layer.
Claim 30
Dependent Claim
31 words
The process according to claim 5 , wherein a porous layer with a porosity higher than the porosity of the high porosity layer is further formed under the high porosity layer.
Claim 31
Dependent Claim
32 words
The process according to claim 1 , further comprising the step of heat treating the porous layer in an oxidizing atmosphere to form a protective film on the walls in the pores.
Claim 32
Dependent Claim
33 words
The process according to claim 1 , further comprising the step of heat treating the porous layer in a reducing atmosphere comprising hydrogen, prior to the step of forming the non-porous single-crystal layer.
Claim 33
Dependent Claim
27 words
The process according to claim 1 , wherein anodization is carried out while allowing a constant current to flow to thereby make the single-crystal semiconductor layer porous.
Claim 34
Dependent Claim
103 words
A process of producing a semiconductor article comprising the steps of: epitaxially growing a single-crystal semiconductor layer on at least one surface of a single-crystal substrate; making porous the single-crystal semiconductor layer to form a high porosity layer and a low porosity layer; forming a non-porous single-crystal layer on a surface of the high porosity layer; and bonding the single-crystal substrate and a support substrate to each other, wherein the bonded single-crystal substrate and support substrate are separated at at least one of a location in the high porosity layer and an interface of the high porosity layer with a layer adjacent thereto.
Claim 35
Dependent Claim
103 words
A process of producing a semiconductor article comprising the steps of: epitaxially growing a single-crystal semiconductor layer on at least one surface of a single-crystal substrate; making porous the single-crystal semiconductor layer to form a high porosity layer and a low porosity layer; forming a non-porous single-crystal layer on a surface of the high porosity layer; and bonding the single-crystal substrate and a support substrate to each other, wherein the bonded single-crystal substrate and support substrate are separated at at least one of a location in the high porosity layer and an interface of the high porosity layer with a layer adjacent thereto.
Claim 36
Dependent Claim
33 words
The process according to claim 33 , further comprising the step of oxidizing the inside wall surfaces of the high porosity layer and then removing an oxide film on the layer surface side.
Claim 37
Dependent Claim
116 words
A process of producing a semiconductor article comprising the steps of: epitaxially growing a single-crystal semiconductor layer on at least one surface of a single-crystal substrate; effecting heat treatment in a reducing atmosphere comprising hydrogen and then making porous the single-crystal semiconductor layer so as to form a high porosity layer and a low porosity layer; forming a non-porous single-crystal layer on a surface of the high porosity layer; and bonding the single-crystal substrate and a support substrate to each other, wherein the bonded single-crystal substrate and support substrate are separated at at least one of a location in the high porosity layer and an interface of the high porosity layer with a layer adjacent thereto.
Claim 38
Dependent Claim
116 words
A process of producing a semiconductor article comprising the steps of: epitaxially growing a single-crystal semiconductor layer on at least one surface of a single-crystal substrate; effecting heat treatment in a reducing atmosphere comprising hydrogen and then making porous the single-crystal semiconductor layer so as to form a high porosity layer and a low porosity layer; forming a non-porous single-crystal layer on a surface of the high porosity layer; and bonding the single-crystal substrate and a support substrate to each other, wherein the bonded single-crystal substrate and support substrate are separated at at least one of a location in the high porosity layer and an interface of the high porosity layer with a layer adjacent thereto.
Claim 39
Dependent Claim
33 words
The process according to claim 35 , wherein a low impurity concentration layer for forming the high porosity layer is formed by the heat treatment in the surface of the single-crystal semiconductor layer.
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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) | 2005-04-22 | 2005-10-22 | 2006-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-04-22 | 2009-10-22 | 2010-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-04-22 | 2013-10-22 | 2014-04-23 | $7700.00 | Window Closed / Lapsed |