Patent US4994892A successfully refreshed from Google Patents.
US4994892A
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Aluminum germanium ohmic contacts to gallium arsenide
Assignee: McDonnell Douglas Corp
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Filing: 1986-10-09
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Granted: 1991-02-19
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Expires: 2006-10-09
Abstract
Abstract Ohmic contacts are attached to n-type Gallium Arsenide with an alloy of Aluminum-Germanium. The contact is prepared by depositing by evaporation a sequence of 400 Angstroms of Germanium, 300 Angstroms of Nickel, and 2000 Angstroms of Aluminum and subsequent alloying.
Inventors
- 👤 Rainer Zuleeg
- 👤 Stanley H. Watanabe
- 👤 John M. Stephens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:52
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/60; H10D64/62; H10D62/00; H10D62/80; H10D62/85
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
42 words
A ohmic contact metallization for use on semiconductor compounds comprising Gallium Arsenide (GaAs), the metallization comprising: an alloyed ensemble of Germanium and Aluminum with sufficient Nickel to provide effective wetting and attachment for the Al and Ge to the GaAs upon alloying.
Claim 2
Dependent Claim
42 words
A ohmic contact metallization for use on semiconductor compounds comprising Gallium Arsenide (GaAs), the metallization comprising: an alloyed ensemble of Germanium and Aluminum with sufficient Nickel to provide effective wetting and attachment for the Al and Ge to the GaAs upon alloying.
Claim 3
Dependent Claim
24 words
The metallization of claim 1 further including an additional first metal interconnect layer of at least 2000 Angstroms of Al atop the alloyed ensemble.
Claim 4
Dependent Claim
38 words
The metallization of claim 1 wherein the ensemble consists essentially of about 400 Angstroms of Ge, then about 300 Angstroms of Ni and then about 2000 Angstroms of Al, with the Ge being the layer adjacent the GaAs.
Claim 5
Dependent Claim
28 words
The metallization of claim 1 wherein the alloying is conducted at about 500° C. for a period of from 1 to 30 minutes in a reducing gas atmosphere.
Claim 6
Dependent Claim
35 words
The metallization of claim 1 wherein the region of the GaAs underlying the alloyed ensemble has a peak impurity concentration of n-type impurity ions of at least about 10 17 cm -3 prior to alloying.
References Cited (Backward Citations)
US3935586A
Cited
US4188710A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-02-18 | 1994-08-20 | 1995-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-18 | 1998-08-20 | 1999-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-18 | 2002-08-20 | 2003-02-19 | $7700.00 | Window Closed / Lapsed |