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US4847675A
Expired / Lapsed
US
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Stable rare-earth alloy graded junction contact devices using III-V type substrates
Assignee: Aerospace Corp
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Filing: 1987-05-07
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Granted: 1989-07-11
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Expires: 2007-05-07
Abstract
Abstract A coating is disclosed for use with GaAs and other Type III-V semiconductor substrates, comprised of a rare-earth element or elements and a non-rare-earth element or elements, that forms an improved graded junction which is thermally stable, has satisfactory electrical properties and is resistant to the through migration of Ga or As.
Inventors
- 👤 Genghmun Eng
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:23
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/80; H10D62/85; H10D64/00; H10D64/60; H10D64/62
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
82 words
A semiconductor device with a graded junction comprising: a. a III-V semiconductor substrate; b. a continuous thin film contact layer upon that substrate, wherein the contact layer is comprised of a graded intermetallic mixture of at least one rare-earth component selected from the group including the rare-earth series, scandium and yttrium and a non-rare earth component consisting of at least one Group IIIa metal selected from the group including Al, In, Tl; c. whereby the contact layer is intermixed with the substrate.
Claim 2
Dependent Claim
82 words
A semiconductor device with a graded junction comprising: a. a III-V semiconductor substrate; b. a continuous thin film contact layer upon that substrate, wherein the contact layer is comprised of a graded intermetallic mixture of at least one rare-earth component selected from the group including the rare-earth series, scandium and yttrium and a non-rare earth component consisting of at least one Group IIIa metal selected from the group including Al, In, Tl; c. whereby the contact layer is intermixed with the substrate.
Claim 3
Dependent Claim
67 words
The semiconductor device as claimed in claim 1 further comprising a continuous alloy layer upon the contact layer, wherein the alloy layer is comprised of an intermetallic mixture of at least one rare-earth component selected from the group including the rare-earth series, scandium and yttrium, and a non-rare-earth component consisting of at least one Group IIIa, a metal selected from the group including Al, In, and Tl.
Claim 4
Dependent Claim
42 words
The semiconductor device as claimed in claim 2 further comprising a continuous cover layer upon the alloy layer wherein the cover layer is comprised of a non-reactive metal such as aluminum, thereby preventing contamination of the contact layer or the alloy layer.
Claim 5
Dependent Claim
38 words
The semiconductor device of claim 1 wherein a dopant is present in the contact layer in amounts less than or equal to 5 mole percent of the total contact layer for tailoring the electrical properties of the device.
Claim 6
Dependent Claim
41 words
The semiconductor device of claim 1 wherein a surface wetting agent is present in the contact layer in amounts less than or equal to 5 mole percent of the total contact layer for improving the surface uniformity of the contact layer.
Claim 7
Dependent Claim
13 words
The device of claim 1 wherein the III-V type semiconductor is gallium arsenide.
Claim 8
Dependent Claim
22 words
The semiconductor device of claim 1 wherein the mole fraction of the rare earth component is between 10 to 90 mole percent.
Claim 9
Dependent Claim
21 words
The semiconductor device of claim 1 wherein the mole fraction of the non-rare-earth component is between 10 to 90 mole percent.
References Cited (Backward Citations)
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US4154874A
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US4141020A
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US4201999A
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US4695869A
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US4593307A
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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) | 1992-07-10 | 1993-01-09 | 1993-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-10 | 1997-01-09 | 1997-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-10 | 2001-01-09 | 2001-07-11 | $7700.00 | Window Closed / Lapsed |