US5100835A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shallow ohmic contacts to N-GaAs
Assignee: Eastman Kodak Co
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Filing: 1991-03-18
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Granted: 1992-03-31
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Expires: 2011-03-18
Abstract
Abstract The formation of low-resistance ohmic contacts to N-GaAs is provided by sequential deposition of Pd/Au-Ge/Ag/Au and rapid thermal annealing.
Inventors
- 👤 Long-ru Zheng
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:13
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0116; H10D64/60; H10D64/62; H10D62/00; H10D62/80; H10D62/85; Y; Y10; Y10S; Y10S148/00; Y10S148/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
92 words
A shallow ohmic contact to an n-type gallium arsenide substrate, comprising: (a) a layer of Pd formed on the surface of the gallium arsenide substrate and having a thickness of 20-100A; (b) a layer of gold germanium formed on the Pd layer and having a thickness of 200-1500A, wherein the germanium has a range of 15-50 atomic percent; (c) a layer of silver formed on the gold germanium layer and having a thickness of 500-1500A; and (d) a layer of gold formed on the silver layer and having a thickness of 500-3000A.
Claim 2
Dependent Claim
92 words
A shallow ohmic contact to an n-type gallium arsenide substrate, comprising: (a) a layer of Pd formed on the surface of the gallium arsenide substrate and having a thickness of 20-100A; (b) a layer of gold germanium formed on the Pd layer and having a thickness of 200-1500A, wherein the germanium has a range of 15-50 atomic percent; (c) a layer of silver formed on the gold germanium layer and having a thickness of 500-1500A; and (d) a layer of gold formed on the silver layer and having a thickness of 500-3000A.
Claim 3
Independent Claim
133 words
A method of making shallow ohmic contact to a n-type gallium arsenide substrate comprising the sequential steps of: (a) evaporating in situ a layer of Pd on the surface of the gallium arsenide substrate, such Pd layer having a thickness of 20-100A; (b) evaporating a layer of gold germanium on the palladium layer, such gold germanium layer having a thickness of 200-1500A wherein the gallium has a range of 15-50 atomic percent; (c) evaporating a layer of silver on the gold germanium layer, such silver layer having a thickness of 500-1500A; and (d) evaporating a layer of gold on the silver layer, such gold layer having a thickness of 500-3000A; and (e) rapidly thermally annealing the system of deposited layers at a temperature of 375°-500° C. for a time of between 10-60 seconds.
Claim 4
Independent Claim
133 words
A method of making shallow ohmic contact to a n-type gallium arsenide substrate comprising the sequential steps of: (a) evaporating in situ a layer of Pd on the surface of the gallium arsenide substrate, such Pd layer having a thickness of 20-100A; (b) evaporating a layer of gold germanium on the palladium layer, such gold germanium layer having a thickness of 200-1500A wherein the gallium has a range of 15-50 atomic percent; (c) evaporating a layer of silver on the gold germanium layer, such silver layer having a thickness of 500-1500A; and (d) evaporating a layer of gold on the silver layer, such gold layer having a thickness of 500-3000A; and (e) rapidly thermally annealing the system of deposited layers at a temperature of 375°-500° C. for a time of between 10-60 seconds.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1995-03-31 | 1995-09-30 | 1996-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-31 | 1999-09-30 | 2000-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-31 | 2003-09-30 | 2004-03-31 | $7700.00 | Window Closed / Lapsed |