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US4596626A
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Method of making macrocrystalline or single crystal semiconductor material
Assignee: National Aeronautics and Space Administration
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Filing: 1983-02-10
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Granted: 1986-06-24
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Expires: 2003-02-10
Abstract
Abstract A macrocrystalline or single crystal semiconductive material is formed from a primary substrate including a single crystal or several very large crystals of a relatively low-melting material. This primary substrate is deposited on a base such as steel or ceramic, and it may be formed from such metals as zinc, cadmium, germanium, aluminum, tin, lead, copper, brass, magnesium silicide, or magnesium stannide. These materials generally have a melting point below about 1000 DEG C. and form on the base crystals the size of fingernails or greater. The primary substrate has an epitaxial relationship with a subsequently applied layer of material, and because of this epitaxial relationship, the material deposited on the primary substrate will have essentially the same crystal size as the crystals in the primary substrate. If required, successive layers are formed, each of a material which has an epitaxial relationship with the previously deposited layer, until a layer is formed which has an epitaxial relationship with the semiconductive material. This layer is referred to as the epitaxial substrate, and its crystals serve as sites for the growth of large crystals of semiconductive material. The primary substrate is passivated to remove or otherwise convert it into a stable or nonreactive state prior to deposition of the semiconductive material.
Inventors
- 👤 Paul J. Shlichta
- 👤 R. James Holliday
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:38
CPC Classifications
C; C30; C30B; C30B25/00; C30B25/02; C30B25/18
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
219 words
A method of making macrocrystalline or single crystal semiconductive material comprising the steps of: (a) depositing on the surface of a base a low melting material having a nonepitaxial relationship with the base with said low melting material having a crystalline form which is not macrocrystalline or a single crystal but which is capable of transformation to a macrocrystalline or single crystal form when treated under selected conditions: (b) treating said low melting material under selected conditions to transform its crystalline form and to produce a primary substrate having a macrocrystalline or single crystal form, with the said treating being carried out either during or after the deposit of the low melting material on the base; (c) forming on or from the primary substrate an epitaxial substrate in the form of macrocrystals or a single crystal having planar dimensions substantially the same as the planar dimensions of said macrocrystals or single crystal in the primary substrate layer, (d) passivating the primary substrate prior to step (c), and (e) depositing on the surface of the epitaxial substrate a semiconductive material which has an epitaxial relationship with the material comprising the epitaxial substrate to form macrocrystals or a single crystal which have planar dimensions substantially the same as the planar dimensions of the macrocrystals or single crystal in the epitaxial substrate.
Claim 2
Independent Claim
219 words
A method of making macrocrystalline or single crystal semiconductive material comprising the steps of: (a) depositing on the surface of a base a low melting material having a nonepitaxial relationship with the base with said low melting material having a crystalline form which is not macrocrystalline or a single crystal but which is capable of transformation to a macrocrystalline or single crystal form when treated under selected conditions: (b) treating said low melting material under selected conditions to transform its crystalline form and to produce a primary substrate having a macrocrystalline or single crystal form, with the said treating being carried out either during or after the deposit of the low melting material on the base; (c) forming on or from the primary substrate an epitaxial substrate in the form of macrocrystals or a single crystal having planar dimensions substantially the same as the planar dimensions of said macrocrystals or single crystal in the primary substrate layer, (d) passivating the primary substrate prior to step (c), and (e) depositing on the surface of the epitaxial substrate a semiconductive material which has an epitaxial relationship with the material comprising the epitaxial substrate to form macrocrystals or a single crystal which have planar dimensions substantially the same as the planar dimensions of the macrocrystals or single crystal in the epitaxial substrate.
Claim 3
Dependent Claim
20 words
The method of claim 1 wherein the material of the primary substrate has a melting point below about 1000° C.
Claim 4
Dependent Claim
26 words
The method of claim 2 wherein the material of the primary substrate is zinc, cadmium, germanium, aluminum, tin, lead, copper, brass, magnesium silicide, or magnesium stannide.
Claim 5
Dependent Claim
15 words
The method of claim 1 wherein the base is iron or an alloy of iron.
Claim 6
Dependent Claim
11 words
The method of claim 1 wherein the base is a ceramic.
Claim 7
Dependent Claim
22 words
The method of claim 1 wherein the base is formed on the primary substrate which is then recrystallized to form large crystals.
Claim 8
Dependent Claim
35 words
The method of claim 1 wherein the primary substrate is formed by applying the low melting material to the base as a molten liquid which covers the base as a thin film and then solidifies.
Claim 9
Dependent Claim
43 words
The method of claim 7 wherein the primary substrate is formed by passing the base through molten metal and withdrawing the substrate from the molten metal at a controlled rate such that it cools slowly to solidify into a single crystal or macrocrystals.
Claim 10
Dependent Claim
16 words
The method of claim 8 wherein the crystals formed are generally parallel and adjacent elongated bands.
Claim 11
Dependent Claim
15 words
The method of claim 1 wherein the epitaxial substrate is formed by gas phase deposition.
Claim 12
Dependent Claim
16 words
The method of claim 1 wherein the epitaxial substrate is formed by electrolytic deposition or reaction.
Claim 13
Dependent Claim
19 words
The method of claim 1 wherein the epitaxial substrate is aluminum oxide (sapphire), and the semiconductive material is silicon.
Claim 14
Dependent Claim
19 words
The method of claim 1 wherein the epitaxial substrate is zinc selenide and the semiconductive material is gallium arsenide.
Claim 15
Dependent Claim
18 words
The method of claim 1 wherein the epitaxial substrate is zinc sulfide and the semiconductive material is silicon.
Claim 16
Dependent Claim
18 words
The method of claim 1 wherein the epitaxial substrate is cadmium and the semiconductive material is cadmium sulfide.
Claim 17
Dependent Claim
18 words
The method of claim 1 wherein the epitaxial substrate is cadmium and the semiconductive material is cadmium telluride.
Claim 18
Dependent Claim
37 words
The method of claim 1 wherein there is deposited a replacement base on the epitaxial layer and wherein the primary substrate is then removed to expose the surface of the epitaxial substrate adhering to the primary substrate.
Claim 19
Dependent Claim
37 words
The method of claim 1 wherein a plurality of successive epitaxial substrates are formed until there is provided an epitaxial substrate of a material which has an epitaxial relationship with a semiconductive material of the desired composition.
Claim 20
Dependent Claim
42 words
The method of claim 18 wherein (a) the base is steel and the primary substrate comprises zinc, (b) an intermediate epitaxial substrate of zinc selenide is formed, and (c) a semiconductive layer of gallium arsenide is formed on the zinc selenide layer.
References Cited (Backward Citations)
US3370980A
Cited
US3368125A
Cited
US3959045A
Cited
US3963538A
Cited
US4116751A
Cited
US4378259A
Cited
GB2080619A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-06-23 | 1989-12-23 | 1990-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-23 | 1993-12-23 | 1994-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-23 | 1997-12-23 | 1998-06-24 | $7700.00 | Window Closed / Lapsed |