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US4255208A
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Method of producing monocrystalline semiconductor films utilizing an intermediate water dissolvable salt layer
Assignee: Ramot at Tel Aviv University Ltd
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Filing: 1979-05-25
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Granted: 1981-03-10
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Expires: 1999-05-25
Abstract
Abstract A method is described for producing semiconductor films, particularly monocrystalline silicon and germanium films, characterized by the steps of: epitaxially growing on a substrate, such as silicon or sapphire, a layer of dissolvable material, such as sodium fluoride, sodium chloride, or silver; epitaxially growing on the dissolvable layer a layer of the semiconductor; and dissolving the dissolvable layer, thereby separating the semiconductor from the substrate. The substrate may thus be reused as a matrix for growing many such films. Also a plurality of semiconductor layers may be epitaxially grown on a common substrate each separated by a dissolvable layer, all the latter layers being dissolved at one time to produce a plurality of the semiconductor films.
Inventors
- 👤 Siegfried G. Deutscher
- 👤 Enrique Grunbaum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:14
CPC Classifications
H; H10; H10F; H10F71/00; H10F71/121; C; C30; C30B; C30B23/00; C30B23/02; C30B25/00; C30B25/02; C30B25/18; H10F71/1212; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/547; Y02P; Y02P70/00; Y02P70/50; Y10; Y10S; Y10S117/00; Y10S117/915; Y10S148/00; Y10S148/026; Y10S148/051; Y10S148/054; Y10S148/135; Y10S148/15; Y10S148/169; Y10S438/00; Y10S438/977
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
58 words
A method of producing monocrystalline semiconductor films, characterized by the steps of: (a) epitaxially growing on a substrate at least one layer of a salt dissolvable in water; (b) epitaxially growing on said salt layer a layer of the monocrystalline semiconductor; and (c) dissolving said salt layer with water, thereby separating the monocrystalline semiconductor layer from the substrate.
Claim 2
Independent Claim
58 words
A method of producing monocrystalline semiconductor films, characterized by the steps of: (a) epitaxially growing on a substrate at least one layer of a salt dissolvable in water; (b) epitaxially growing on said salt layer a layer of the monocrystalline semiconductor; and (c) dissolving said salt layer with water, thereby separating the monocrystalline semiconductor layer from the substrate.
Claim 3
Dependent Claim
43 words
The method according to claim 1, wherein a monocrystalline semi-conductor of one type is epitaxially grown on said salt layer, and then a monocrystalline semiconductor of another type is epitaxially grown on said latter layer before the salt layer is dissolved with water.
Claim 4
Dependent Claim
24 words
The method according to claim 2, wherein said epitaxially-grown layers are grown by evaporation in a high vacuum of at least 10 6 torr.
Claim 5
Dependent Claim
13 words
The method according to claim 1, wherein the epitaxially-grown semiconductor layer is silicon.
Claim 6
Dependent Claim
27 words
The method according to claim 4, wherein a thin film of germanium is epitaxially grown on the dissolvable salt layer before epitaxially growing the silicon layer thereon.
Claim 7
Dependent Claim
12 words
The method according to claim 1, wherein the epitaxially-grown semiconductor is germanium.
Claim 8
Dependent Claim
11 words
The method according to claim 1, wherein the substrate is silicon.
Claim 9
Dependent Claim
26 words
The method according to claim 7, wherein a thin film of germanium is epitaxially grown on the silicon substrate before epitaxially growing the dissolvable layer thereon.
Claim 10
Dependent Claim
11 words
The method according to claim 1, wherein the substrate is sapphire.
Claim 11
Dependent Claim
16 words
The method according to claim 1, wherein the dissolvable layer includes a film of sodium fluoride.
Claim 12
Dependent Claim
16 words
The method according to claim 1, wherein the dissolvable layer includes a film of sodium chloride.
Claim 13
Dependent Claim
17 words
The method according to claim 11, wherein the dissolvable layer further includes an overlying film of silver.
Claim 14
Dependent Claim
25 words
The method according to claim 2, wherein the semiconductor layer of one type is germanium and the semiconductor layer of the other type is silicon.
Claim 15
Dependent Claim
15 words
The method according to claim 1, wherein the dissolvable layer includes a film of silver.
Claim 16
Dependent Claim
35 words
The method according to claim 4, wherein a layer of germanium is epitaxially grown on the dissolvable layer before epitaxially growing the silicon layer thereon, and of a thickness substantially equal to said silicon layer.
Claim 17
Dependent Claim
22 words
The method according to claim 1, wherein electrical contacts are evaporated on the epitaxially-grown semiconductor layer before the dissolvable layer is dissolved.
Claim 18
Dependent Claim
23 words
The method according to claim 1, wherein an antireflective coating is evaporated on the epitaxially-grown semiconductor layer before the dissolvable layer is dissolved.
Claim 19
Dependent Claim
47 words
The method according to claim 1, wherein a plurality of semiconductor layers are epitaxially-grown on a common substrate with each layer being separated by an epitaxially-grown layer of dissolvable material, all said latter layers being dissolved at one time to produce a plurality of separate semiconductor films.
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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) | 1984-03-09 | 1984-09-08 | 1985-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-09 | 1988-09-08 | 1989-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-09 | 1992-09-08 | 1993-03-10 | $7700.00 | Window Closed / Lapsed |