Patent US5435264A successfully refreshed from Google Patents.
US5435264A
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US
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Process for forming epitaxial BaF2 on GaAs
Assignee: United States Department of the Navy
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Filing: 1994-05-19
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Granted: 1995-07-25
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Expires: 2014-05-19
Abstract
Abstract A process for growing single crystal epitaxial BaF 2 layers on gallium arsenide substrates by slowly reacting BaF 2 vapor with the clean, hot GaAs substrate at 500° to 700° C. in high vacuum until a uniform, thin (˜12Å) layer of reaction product is formed and then vapor depositing BaF 2 onto the reaction layer at room temperature to 400° C. to form the single crystal, epitaxial BaF 2 layer.
Inventors
- 👤 Francisco Santiago
- 👤 Tak K. Chu
- 👤 Michael F. Stumborg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:53
CPC Classifications
C; C30; C30B; C30B23/00; C30B23/02; C30B25/00; C30B25/02; C30B29/00; C30B29/10; C30B29/12
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
165 words
A process for forming a uniform, single crystal, epitaxial layer of barium fluoride on a single crystal gallium arsenide substrate comprising A. vapor depositing barium fluoride on a clean, hot single crystal gallium arsenide substrate at a temperature of from 500° to 700° C., in a vacuum having a background pressure of less than 10 -8 millibars and wherein the barium fluoride deposition is slow enough to allow the barium fluoride vapor to react with the gallium arsenide substrate surface and form a uniform, epitaxial coating of barium fluoride/gallium arsenide reaction product and continuing until the reaction product layer is completed and a single crystal epitaxial barium fluoride has begun to be formed on the reaction layer, and then B. reducing the temperature of the substrate to a temperature of from room temperature to 400° C. and depositing the barium fluoride at a rate of from 1 to 100Å per minute until the desired thickness of uniform, single crystal, epitaxial barium fluoride has been achieved.
Claim 2
Dependent Claim
165 words
A process for forming a uniform, single crystal, epitaxial layer of barium fluoride on a single crystal gallium arsenide substrate comprising A. vapor depositing barium fluoride on a clean, hot single crystal gallium arsenide substrate at a temperature of from 500° to 700° C., in a vacuum having a background pressure of less than 10 -8 millibars and wherein the barium fluoride deposition is slow enough to allow the barium fluoride vapor to react with the gallium arsenide substrate surface and form a uniform, epitaxial coating of barium fluoride/gallium arsenide reaction product and continuing until the reaction product layer is completed and a single crystal epitaxial barium fluoride has begun to be formed on the reaction layer, and then B. reducing the temperature of the substrate to a temperature of from room temperature to 400° C. and depositing the barium fluoride at a rate of from 1 to 100Å per minute until the desired thickness of uniform, single crystal, epitaxial barium fluoride has been achieved.
Claim 3
Dependent Claim
17 words
The process of claim 1 wherein the temperature in step A is from 550° to 650° C.
Claim 4
Dependent Claim
17 words
The process of claim 2 wherein the temperature in step A is from 575° to 625° C.
Claim 5
Dependent Claim
23 words
The process of claim 1 wherein the vacuum in steps A and B has a background pressure of less than 10 -9 millibars.
Claim 6
Dependent Claim
23 words
The process of claim 4 wherein the vacuum in steps A and B has a background pressure of less than 10 -10 millibars.
Claim 7
Dependent Claim
20 words
The process of claim 1 wherein barium fluoride deposition rate in step A is from 1 to 5Å per minute.
Claim 8
Dependent Claim
21 words
The process of claim 6 wherein the barium fluoride deposition rate in step A is from 2 to 3Å per minute.
Claim 9
Dependent Claim
19 words
The process of claim 1 wherein the temperature used in step B is from room temperature to 300° C.
Claim 10
Dependent Claim
15 words
The process of claim 8 wherein the temperature used in step B is room temperature.
Claim 11
Dependent Claim
21 words
The process of claim 1 wherein the barium fluoride deposition rate in step B is from 1 to 50Å per minute.
Claim 12
Dependent Claim
21 words
The process of claim 10 wherein the barium fluoride deposition rate in step B is from 1 to 5Å per minute.
Claim 13
Dependent Claim
96 words
The process of claim 1 wherein the single crystal gallium arsenide substrate is selected from the group consisting of gallium arsenide single crystal wafers, gallium arsenide epitaxial layers on gallium arsenide single crystal wafers, epitaxial layers of gallium arsenide alloys on single crystal gallium arsenide wafers, heterostructures of super-lattice made of combinations of gallium arsenide alloys on gallium arsenide single wafers, gallium arsenide single crystal epitaxial layers on suitable substrate materials, epitaxial layers of gallium arsenide alloys on suitable substrate materials, and heterostructures of super-lattice made of combinations of gallium arsenide alloys on suitable substrate materials.
Claim 14
Dependent Claim
45 words
The process of claim 12 wherein the single crystal gallium arsenide substrate is selected from the group consisting of gallium arsenide single crystal wafers, gallium arsenide epitaxial layers on gallium arsenide single crystal wafers, and gallium arsenide single crystal epitaxial layers on suitable substrate materials.
Claim 15
Dependent Claim
24 words
The process of claim 13 wherein the single crystal gallium arsenide substrate is selected from the group consisting of gallium arsenide single crystal wafers.
Claim 16
Dependent Claim
31 words
The process of claim 13 wherein the single crystal gallium arsenide substrate is selected from the group consisting of gallium arsenide single crystal epitaxial layers on gallium arsenide single crystal wafers.
Claim 17
Dependent Claim
19 words
The process of claim 1 wherein the single crystal gallium arsenide substrate surface has a (100) or equivalent orientation.
Claim 18
Dependent Claim
17 words
The process of claim 16 wherein the single crystal gallium arsenide substrate surface has a (100) orientation.
Claim 19
Dependent Claim
20 words
The process of claim 1 wherein the single crystal gallium arsenide substrate surface has a (111 ) or equivalent orientation.
Claim 20
Dependent Claim
18 words
The process of claim 18 wherein the single crystal gallium arsenide substrate surface has a (111 ) orientation.
References Cited (Backward Citations)
US4368098A
Cited
US4404265A
Cited
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