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US4330343A
Expired / Lapsed
US
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Refractory passivated ion-implanted GaAs ohmic contacts
Assignee: United States Department of the Navy
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Filing: 1980-12-10
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Granted: 1982-05-18
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Expires: 2000-12-10
Abstract
Abstract A method of attaining n + regions with fine planar geometry in the soe and drain of GaAs devices utilizing ion implantation which improves ohmic contact with a refractory film. A layer of TiW refractory film is deposited on GaAs. 29 Si ions are implanted in the GaAs through the refractory film so that the peak concentration is no more than approximately 100A below the TiW-GaAs interface. The entire structure is then annealed. A gold overlay is then deposited on the TiW layer to which electrical contacts may be attached and by which the contact resistivity is measured. Typical specific contact resistivity values are in the low 10 -6 ohm/cm 2 range.
Inventors
- 👤 Aristos Christou
- 👤 John E. Davey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:50
CPC Classifications
H; H10; H10P; H10P30/00; H10P30/20; H10P30/202; H10P30/206; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0116; H10P30/21; H10P30/212; H10P30/28; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/064; Y; Y10; Y10S; Y10S148/00; Y10S148/003; Y10S148/02
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
79 words
A method for forming an improved ohmic contact for semiconductors comprising the steps of: depositing a layer of refractory material on a N-type GaAs base material to form a refractory mask; implanting ions through the refractory mask to establish an n + region in the GaAs base material with a peak concentration within about 100 A of the refractory mask-GaAs interface. annealing the implanted structure to activate the implanted ions; and depositing a gold overlay on the refractory mask.
Claim 2
Independent Claim
79 words
A method for forming an improved ohmic contact for semiconductors comprising the steps of: depositing a layer of refractory material on a N-type GaAs base material to form a refractory mask; implanting ions through the refractory mask to establish an n + region in the GaAs base material with a peak concentration within about 100 A of the refractory mask-GaAs interface. annealing the implanted structure to activate the implanted ions; and depositing a gold overlay on the refractory mask.
Claim 3
Dependent Claim
33 words
The method according to claim 1 comprising the step of depositing a refractory mask selected from the group consisting of TiW, Ta, W, Pt, and Mo to a thickness of from 400-800 A.
Claim 4
Dependent Claim
26 words
The method according to claim 1 or 2 comprising the step of selecting an implantation material from the group consisting of 29 Si, Se and Ge.
Claim 5
Dependent Claim
42 words
The method according to claim 3 where said ions are implanted at 60 KeV with a minimum dosage of 1×10 14 ions per cm 2 until the ion concentration within said GaAs is at least 1×10 14 ions per cm 2 .
Claim 6
Dependent Claim
21 words
The method according to claim 3 comprising the step of annealing the structure at about 700° C. for about 30 minutes.
Claim 7
Dependent Claim
21 words
The method according to claim 4 comprising the step of annealing the structure at about 700° C. for about 30 minutes.
Claim 8
Dependent Claim
23 words
The method according to claim 1 or 2 comprising the step of annealing the structure at about 700° C. for about 30 minutes.
Claim 9
Dependent Claim
19 words
The invention according to claim 1 wherein the gold overlay is deposited to a thickness of about 3000 A.
Claim 10
Dependent Claim
16 words
The invention according to claim 1 or 8 wherein the gold overlay is deposited by evaporation.
Claim 11
Dependent Claim
16 words
The invention according to claim 1 or 8 wherein the gold overlay is deposited by sputtering.
Claim 12
Dependent Claim
16 words
The invention according to claim 1 or 8 wherein the gold overlay is deposited by electroplating.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-05-17 | 1985-11-16 | 1986-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-17 | 1989-11-16 | 1990-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-17 | 1993-11-16 | 1994-05-18 | $7700.00 | Window Closed / Lapsed |