US4345967A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing thin single-crystal sheets
Assignee: Individual
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Filing: 1980-03-04
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Granted: 1982-08-24
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Expires: 2000-03-04
Abstract
Abstract A method of producing thin single-crystal sheets is disclosed. A thin single-crystal layer is formed on a substrate, with the material of the layer having a different absorption coefficient for laser radiation than does the material of the substrate at their interface. The laser radiation is focused into a region contiguous to the interface and extending the width of the interface, and is swept across the entire interface region. The energy that is absorbed from the laser radiation in the focus region liquifies material in this region. The layer is progressively separated from the substrate as the laser radiation is swept across the interface, until the entire layer is separated from the substrate. The method is applicable to the production of thin single-crystal sheets of semiconductor material which may be used, for example, in the manufacture of solar cells or integrated circuits.
Inventors
- 👤 Melvin S. Cook
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:59
CPC Classifications
C; C30; C30B; C30B33/00; C30B29/00; C30B29/60; Y; Y10; Y10S; Y10S117/00; Y10S117/903; Y10S117/904; Y10S117/915
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
118 words
A method of producing thin crystals comprising the steps of epitaxially growing an attached layer of crystal on a substrate, said layer of crystal being transparent to radiation of at least one particular wavelength to which said substrate is absorptive in a region of said substrate adjacent the interface of said substrate with said layer of crystal, directing radiation of said at least one particular wavelength into at least part of said absorptive region through said layer of crystal such that material of said at least part but not all of said absorptive region liquifies at the interface of said layer of crystal and substrate, and separating said layer of crystal from said substrate at the liquified material.
Claim 2
Independent Claim
118 words
A method of producing thin crystals comprising the steps of epitaxially growing an attached layer of crystal on a substrate, said layer of crystal being transparent to radiation of at least one particular wavelength to which said substrate is absorptive in a region of said substrate adjacent the interface of said substrate with said layer of crystal, directing radiation of said at least one particular wavelength into at least part of said absorptive region through said layer of crystal such that material of said at least part but not all of said absorptive region liquifies at the interface of said layer of crystal and substrate, and separating said layer of crystal from said substrate at the liquified material.
Claim 3
Dependent Claim
13 words
A method in accordance with claim 1 wherein said radiation is laser radiation.
Claim 4
Dependent Claim
18 words
A method in accordance with claim 1 wherein said layer of crystal is grown with a single-crystal structure.
Claim 5
Dependent Claim
13 words
A method in accordance with claim 3 wherein said radiation is laser radiation.
Claim 6
Independent Claim
120 words
A method of producing thin crystals comprising the steps of epitaxially growing an attached layer of crystal on a substrate, said layer of crystal being absorptive of radiation of at least one particular wavelength to which said substrate is transmissive in a region of said layer of crystal at the interface of said layer of crystal with said substrate, directing radiation of said at least one particular wavelength into at least part of said absorptive region through said substrate such that material of said at least part but not all of said absorptive region liquifies at the interface of said layer of crystal and substrate, and separating said layer of crystal from said substrate where said liquified material is present.
Claim 7
Independent Claim
120 words
A method of producing thin crystals comprising the steps of epitaxially growing an attached layer of crystal on a substrate, said layer of crystal being absorptive of radiation of at least one particular wavelength to which said substrate is transmissive in a region of said layer of crystal at the interface of said layer of crystal with said substrate, directing radiation of said at least one particular wavelength into at least part of said absorptive region through said substrate such that material of said at least part but not all of said absorptive region liquifies at the interface of said layer of crystal and substrate, and separating said layer of crystal from said substrate where said liquified material is present.
Claim 8
Dependent Claim
13 words
A method in accordance with claim 5 wherein said radiation is laser radiation.
Claim 9
Dependent Claim
18 words
A method in accordance with claim 5 wherein said layer of crystal is grown with a single-crystal structure.
Claim 10
Dependent Claim
13 words
A method in accordance with claim 7 wherein said radiation is laser radiation.
Claim 11
Independent Claim
117 words
A method of producing thin crystals comprising the steps of epitaxially growing an attached layer of crystal on a substrate, said layer of crystal being absorptive of radiation to which said substrate is transmissive in at least part of said layer of crystal, adhering a metal foil to said layer of crystal, directing said radiation into said at least part of said layer of crystal through said substrate such that material of said at least part but not all of said layer of crystal liquifies to form a liquid at the interface of said layer of crystal and substrate, and separating said layer of crystal adhered to said metal foil from said substrate at the liquified material.
Claim 12
Independent Claim
117 words
A method of producing thin crystals comprising the steps of epitaxially growing an attached layer of crystal on a substrate, said layer of crystal being absorptive of radiation to which said substrate is transmissive in at least part of said layer of crystal, adhering a metal foil to said layer of crystal, directing said radiation into said at least part of said layer of crystal through said substrate such that material of said at least part but not all of said layer of crystal liquifies to form a liquid at the interface of said layer of crystal and substrate, and separating said layer of crystal adhered to said metal foil from said substrate at the liquified material.
Claim 13
Dependent Claim
13 words
A method in accordance with claim 9 wherein said radiation is laser radiation.
Claim 14
Dependent Claim
18 words
A method in accordance with claim 9 wherein said layer of crystal is grown with a single-crystal structure.
Claim 15
Dependent Claim
13 words
A method in accordance with claim 11 wherein said radiation is laser radiation.
Claim 16
Independent Claim
124 words
A method of producing thin crystals comprising the steps of epitaxially growing an attached layer of crystal on a substrate, one of said layer of crystal and said substrate being transparent to radiation of at least one particular wavelength to which the other of said layer of crystal and said substrate is absorptive in a region at the interface of said substrate and said layer of crystal, directing radiation of said at least one particular wavelength into at least part of the absorptive one of said layer of crystal and said substrate through the other such that absorptive material liquifies only at the interface of said layer of crystal and substrate, and separating said layer of crystal from said substrate at the liquified material.
Claim 17
Independent Claim
124 words
A method of producing thin crystals comprising the steps of epitaxially growing an attached layer of crystal on a substrate, one of said layer of crystal and said substrate being transparent to radiation of at least one particular wavelength to which the other of said layer of crystal and said substrate is absorptive in a region at the interface of said substrate and said layer of crystal, directing radiation of said at least one particular wavelength into at least part of the absorptive one of said layer of crystal and said substrate through the other such that absorptive material liquifies only at the interface of said layer of crystal and substrate, and separating said layer of crystal from said substrate at the liquified material.
Claim 18
Dependent Claim
46 words
A method in accordance with claim 13 wherein said radiation of said at least one particular wavelength is transmitted through the transparent one of said layer of crystal and said substrate on its way to the absorptive one of said layer of crystal and said substrate.
Claim 19
Dependent Claim
32 words
A method in accordance with claim 14 wherein said radiation is swept across said interface and said layer of crystal is separated in the region of said interface which has been irradiated.
Claim 20
Dependent Claim
13 words
A method in accordance with claim 15 wherein said radiation is laser radiation.
Claim 21
Dependent Claim
18 words
A method in accordance with claim 16 wherein said layer of crystal is grown with a single-crystal structure.
Claim 22
Dependent Claim
30 words
A method in accordance with claim 14 further including the step of adhering a sheet of material to said layer of crystal prior to the separation thereof from said substrate.
Claim 23
Dependent Claim
25 words
A method in accordance with claim 18 wherein said sheet of material is pulled to effect separation of said layer of crystal from said substrate.
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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) | 1985-08-23 | 1986-02-22 | 1986-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-23 | 1990-02-22 | 1990-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-23 | 1994-02-22 | 1994-08-24 | $7700.00 | Window Closed / Lapsed |