US6140209A
Expired / Lapsed
US
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Process for forming an SOI substrate
Assignee: Canon Inc
•
Filing: 1998-03-23
•
Granted: 2000-10-31
•
Expires: 2018-03-23
Abstract
Abstract A process for producing an SOI substrate is disclosed which is useful for saving resources and lowering production cost. Further, a process for producing a photoelectric conversion device such as a solar cell is disclosed which can successfully separate a substrate by a porous Si layer, does not require a strong adhesion between a substrate and a jig, and can save resources and lower production cost. In a substrate having a porous layer on a nonporous layer and further having on the porous layer a layer small in porosity, the nonporous layer and the layer small in porosity are separated by the porous layer to form a thin film. A metal wire is wound around a side surface of the substrate, and a current is made to flow into the metal wire to generate a heat from the metal wire and transfer the heat preferentially to the porous layer, thus conducting the separation. The separated substrate is used for producing an SOI substrate and the separated nonporous Si layer is reutilized in a process of producing an SOI substrate.
Inventors
- 👤 Masaaki Iwane
- 👤 Takao Yonehara
- 👤 Kazuaki Ohmi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 20:00
CPC Classifications
B; B32; B32B; B32B43/00; H; H10; H10F; H10F99/00; H10P; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1914; H10P90/1924; H10W; H10W10/00; H10W10/10; H10W10/181; Y; Y10; Y10S; Y10S438/00; Y10S438/96; Y10S438/974; Y10S438/977
Claims Analysis
Total Claims: 55
Claim 1
Independent Claim
69 words
A process for forming a thin film which prepares a substrate having a porous layer on a nonporous layer and further having on the porous layer a layer smaller in porosity than the porous layer, and separates the nonporous layer and the layer smaller in porosity by the porous layer, the process comprising bringing a wire into contact with a side surface of the substrate to effect the separation.
Claim 2
Dependent Claim
69 words
A process for forming a thin film which prepares a substrate having a porous layer on a nonporous layer and further having on the porous layer a layer smaller in porosity than the porous layer, and separates the nonporous layer and the layer smaller in porosity by the porous layer, the process comprising bringing a wire into contact with a side surface of the substrate to effect the separation.
Claim 3
Dependent Claim
22 words
The process as claimed in claim 1, wherein the wire is wound on the side surface of the substrate least once around.
Claim 4
Dependent Claim
30 words
The process as claimed in claim 2, wherein the wire is electrically conductive, and wherein a current is allowed to flow into the wire to generate heat from the wire.
Claim 5
Dependent Claim
29 words
The process as claimed in claim 2, wherein the wire is electrically conductive, and wherein a current is allowed to flow into the wire to thermally expand the wire.
Claim 6
Dependent Claim
43 words
The process as claimed in claim 2, wherein the wire is electrically conductive, and wherein a current is allowed to flow into the wire while applying a magnetic field to the outside of the wire, thereby exerting the Lorentz's force on the wire.
Claim 7
Dependent Claim
32 words
The process as claimed in claim 5, wherein the magnetic field is a static magnetic field, and wherein an alternating current is allowed to flow into the wire to vibrate the wire.
Claim 8
Dependent Claim
49 words
The process as claimed in claim 5, wherein the magnetic field is a static magnetic field, and wherein a direct current is allowed to flow into the wire to exert a force on the substrate from the wire in a direction of peeling off the layer smaller in porosity.
Claim 9
Dependent Claim
17 words
The process as claimed in claim 2, wherein the wire is tightened up to separate the substrate.
Claim 10
Dependent Claim
27 words
The process as claimed in claim 1, wherein the wire is a bimetal, and wherein the wire is heated to be thermally deformed to conduct the separation.
Claim 11
Dependent Claim
31 words
The process as claimed in claim 1, wherein the wire is a shape-memory alloy, and wherein the wire is deformed by using the shape-memory of the wire to conduct the separation.
Claim 12
Dependent Claim
23 words
The process as claimed in claim 1, wherein the porous layer on the nonporous layer is formed by anodization of an Si wafer.
Claim 13
Dependent Claim
48 words
The process as claimed in claim 1, wherein a rear surface of the nonporous layer which is not in contact with the porous layer is brought into close contact with a vacuum chuck, and wherein a small pulling force is propagated to the substrate from the vacuum chuck.
Claim 14
Dependent Claim
26 words
The process as claimed in claim 11, wherein the layer smaller in porosity is a nonporous epitaxial layer formed by epitaxial growth on the porous layer.
Claim 15
Dependent Claim
72 words
The process as claimed in claim 13, wherein after the epitaxial layer and a support substrate having an insulating layer at least on a surface thereof are bonded to each other, separation is performed by the porous layer, and the porous layer remaining on the epitaxial layer is removed to use the epitaxial layer and the insulating layer for a semiconductor layer and an underlying insulating layer of an SOI substrate, respectively.
Claim 16
Dependent Claim
33 words
The process as claimed in claim 14, wherein the support substrate having an insulating layer at least on a surface thereof is a substrate obtained by oxidizing a surface of an Si wafer.
Claim 17
Dependent Claim
73 words
The process as claimed in claim 11, wherein after an insulating layer is formed on a surface of the epitaxial layer and the insulating layer is bonded to a support substrate, separation is performed by the porous Si layer, and the porous layer remaining on the epitaxial layer is removed to use the epitaxial layer and the insulating layer for a semiconductor layer and an underlying insulating layer of an SOI substrate, respectively.
Claim 18
Dependent Claim
15 words
The process as claimed in claim 16, wherein the support substrate is a quartz substrate.
Claim 19
Dependent Claim
23 words
The process as claimed in claim 16, wherein the support substrate is a substrate obtained by oxidizing a surface of an Si wafer.
Claim 20
Dependent Claim
31 words
The process as claimed in claim 11, wherein the layer smaller in porosity is formed by conducting anodization at a smaller current density than that used when forming the porous layer.
Claim 21
Dependent Claim
49 words
The process as claimed in claim 14 or 19, wherein after the layer smaller in porosity and the support substrate are bonded to each other, separation is performed by the porous layer to use the layer small in porosity for the photoelectric conversion layer of a photoelectric conversion device.
Claim 22
Dependent Claim
77 words
A process for forming a thin film which prepares a substrate having a porous Si layer on a nonporous Si layer and further having on the porous Si layer an Si layer smaller in porosity than the porous Si layer, and separates the nonporous Si layer and the Si layer smaller in porosity by the porous Si layer, the process comprising bringing a wire into contact with a side surface of the substrate to effect the separation.
Claim 23
Dependent Claim
77 words
A process for forming a thin film which prepares a substrate having a porous Si layer on a nonporous Si layer and further having on the porous Si layer an Si layer smaller in porosity than the porous Si layer, and separates the nonporous Si layer and the Si layer smaller in porosity by the porous Si layer, the process comprising bringing a wire into contact with a side surface of the substrate to effect the separation.
Claim 24
Dependent Claim
23 words
The process as claimed in claim 21, wherein the wire is wound on the side surface of the substrate at least once around.
Claim 25
Dependent Claim
30 words
The process as claimed in claim 22, wherein the wire is electrically conductive, and wherein a current is allowed to flow into the wire to generate heat from the wire.
Claim 26
Dependent Claim
29 words
The process as claimed in claim 22, wherein the wire is electrically conductive, and wherein a current is allowed to flow into the wire to thermally expand the wire.
Claim 27
Dependent Claim
43 words
The process as claimed in claim 22, wherein the wire is electrically conductive, and wherein a current is allowed to flow into the wire while applying a magnetic field to the outside of the wire, thereby exerting the Lorentz's force on the wire.
Claim 28
Dependent Claim
32 words
The process as claimed in claim 25, wherein the magnetic field is a static magnetic field, and wherein an alternating current is allowed to flow into the wire to vibrate the wire.
Claim 29
Dependent Claim
49 words
The process as claimed in claim 25, wherein the magnetic field is a static magnetic field, and wherein a direct current is allowed to flow into the wire to exert a force on the substrate from the wire in a direction of peeling off the layer smaller in porosity.
Claim 30
Dependent Claim
17 words
The process as claimed in claim 22, wherein the wire is tightened up to separate the substrate.
Claim 31
Dependent Claim
27 words
The process as claimed in claim 21, wherein the wire is a bimetal, and wherein the wire is heated to be thermally deformed to conduct the separation.
Claim 32
Dependent Claim
31 words
The process as claimed in claim 21, wherein the wire is a shape-memory alloy, and wherein the wire is deformed by using the shape-memory of the wire to conduct the separation.
Claim 33
Dependent Claim
25 words
The process as claimed in claim 21, wherein the porous Si layer on the nonporous Si layer is formed by anodization of an Si wafer.
Claim 34
Dependent Claim
50 words
The process as claimed in claim 21, wherein a rear surface of the nonporous Si layer which is not in contact with the porous Si layer is brought into close contact with a vacuum chuck, and wherein a small pulling force is propagated to the substrate from the vacuum chuck.
Claim 35
Dependent Claim
28 words
The process as claimed in claim 31, wherein the Si layer smaller in porosity is an epitaxial Si layer formed by epitaxial growth on the porous Si layer.
Claim 36
Dependent Claim
77 words
The process as claimed in claim 33, wherein after the epitaxial Si layer and a support substrate having an insulating layer at least on a surface thereof are bonded to each other, separation is performed by the porous Si layer, and the porous Si layer remaining on the epitaxial Si layer is removed to use the epitaxial Si layer and the insulating layer for a semiconductor layer and an underlying insulating layer of an SOI substrate, respectively.
Claim 37
Dependent Claim
33 words
The process as claimed in claim 34, wherein the support substrate having an insulating layer at least on a surface thereof is a substrate obtained by oxidizing a surface of an Si wafer.
Claim 38
Dependent Claim
77 words
The process as claimed in claim 31, wherein after an insulating layer is formed on a surface of the epitaxial Si layer and the insulating layer is bonded to a support substrate, separation is performed by the porous Si layer, and the porous Si layer remaining on the epitaxial Si layer is removed to use the epitaxial Si layer and the insulating layer for a semiconductor layer and an underlying insulating layer of an SOI substrate, respectively.
Claim 39
Dependent Claim
15 words
The process as claimed in claim 36, wherein the support substrate is a quartz substrate.
Claim 40
Dependent Claim
23 words
The process as claimed in claim 36, wherein the support substrate is a substrate obtained by oxidizing a surface of an Si wafer.
Claim 41
Dependent Claim
33 words
The process as claimed in claim 31, wherein the Si layer smaller in porosity is formed by conducting anodization at a smaller current density than that used when forming the porous Si layer.
Claim 42
Dependent Claim
52 words
The process as claimed in claim 34 or 39, wherein after the Si layer small in porosity and the support substrate are bonded to each other, separation is performed by the porous Si layer to use the Si layer small in porosity for the photoelectric conversion layer of a photoelectric conversion device.
Claim 43
Dependent Claim
65 words
A process for forming a thin film, comprising the steps of: implanting hydrogen ions or rare gas ions into first substrate to form an ion-implanted layer inside the first substrate; bonding the first substrate and a second substrate to each other; and bringing a wire into contact with a side surface of the bonded first and second substrates to effect separation by the ion-implanted layer.
Claim 44
Dependent Claim
65 words
A process for forming a thin film, comprising the steps of: implanting hydrogen ions or rare gas ions into first substrate to form an ion-implanted layer inside the first substrate; bonding the first substrate and a second substrate to each other; and bringing a wire into contact with a side surface of the bonded first and second substrates to effect separation by the ion-implanted layer.
Claim 45
Dependent Claim
66 words
A process for forming a thin film, comprising the steps of: implanting hydrogen ions or rare gas ions into a silicon substrate to form a defective layer containing microbubbles inside the silicon substrate; bonding the silicon substrate and another substrate to each other; and bringing a wire into contact with a side surface of the bonded substrates to effect separation by the defective layer containing microbubbles.
Claim 46
Dependent Claim
66 words
A process for forming a thin film, comprising the steps of: implanting hydrogen ions or rare gas ions into a silicon substrate to form a defective layer containing microbubbles inside the silicon substrate; bonding the silicon substrate and another substrate to each other; and bringing a wire into contact with a side surface of the bonded substrates to effect separation by the defective layer containing microbubbles.
Claim 47
Dependent Claim
20 words
The process as claimed in claim 42, wherein the wire is wound on the side surface at least once around.
Claim 48
Dependent Claim
30 words
The process as claimed in claim 43, wherein the wire is electrically conductive, and wherein a current is allowed to flow into the wire to generate heat from the wire.
Claim 49
Dependent Claim
29 words
The process as claimed in claim 43, wherein the wire is electrically conductive, and wherein a current is allowed to flow into the wire to thermally expand the wire.
Claim 50
Dependent Claim
43 words
The process as claimed in claim 43, wherein the wire is electrically conductive, and wherein a current is allowed to flow into the wire while applying a magnetic field to the outside of the wire, thereby exerting the Lorentz's force on the wire.
Claim 51
Dependent Claim
32 words
The process as calimed in claim 46, wherein the magnetic field is a static magnetic field, and wherein an alternating current is allowed to flow into the wire to vibrate the wire.
Claim 52
Dependent Claim
28 words
The process as claimed in claim 46, wherein the magnetic field is a static magnetic field, and wherein a direct current is allowed to flow into the wire.
Claim 53
Dependent Claim
13 words
The process as claimed in claim 43, wherein the wire is tightened up.
Claim 54
Dependent Claim
27 words
The process as claimed in claim 42, wherein the wire is a bimetal, and wherein the wire is heated to be thermally deformed to conduct the separation.
Claim 55
Dependent Claim
31 words
The process as claimed in claim 42, wherein the wire is a shape-memory alloy, and wherein the wire is deformed by using the shape-memory of the wire to conduct the separation.
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US5371037A
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JPH07302889A
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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) | 2003-10-31 | 2004-05-01 | 2004-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-10-31 | 2008-05-01 | 2008-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-10-31 | 2012-05-01 | 2012-10-31 | $7700.00 | Window Closed / Lapsed |