Patent US3923975A successfully refreshed from Google Patents.
US3923975A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tantalum-gallium arsenide schottky barrier semiconductor device
Assignee: Cutler Hammer Inc
•
Filing: 1975-01-23
•
Granted: 1975-12-02
•
Expires: 1995-01-23
Abstract
Abstract A Schottky barrier semiconductor device wherein the semiconductor is gallium arsenide and the metal electrode is tantalum, passivated by formation of native oxides after the metal-semiconductor junction is made. Tantalum acts as a diffusion shield, enabling use of gold as a direct contact on the electrode.
Inventors
- 👤 Joseph A Calviello
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:52
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/012; H10D64/0124; H10D64/0125; H10D30/00; H10D30/60; H10D30/67; H10D30/6729; H10D30/6737; H10D30/6738; H10D30/674; H10D30/675; H10D62/00; H10D62/80; H10D62/85; H10D64/60; H10D64/64; H10D8/00; H10D8/60; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6306; H10P14/6312; H10P14/6314; H10P14/65; H10P14/6502; H10P14/6512; H10P14/69; H10P14/692; H10P14/6938; H10P14/6939; H10P14/69393; Y; Y10; Y10S; Y10S438/00; Y10S438/974
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
105 words
A METHOD OF FABRICATING A SCHOTTKY BARRIER ELECTRODE STRUCTURE ON A BODY OF GALLIUM ARSENIDE, COMPRISING THE STEPS OF A. CLEANING THE SURFACE OF SAID BODY, B. DEPOSITING A FILM OF TANTALUM ON A REGION OF SAID SURFACE BY EVAPORATING IN VACUUM IN THE ABSENCE OF WATER, WHILE MAINTAINING THE PRESSURE BELOW ABOUT 10**5 MM HG, TO A FILM THICKNESS OF ABOUT 2000A. C. DEPOSITING A GOLD FILM UPON SAID TANTALUM FILM, D. ETCHING THE EXPOSED SURFACE OF SAID GALLIUM ARSENIDE BODY TO DEFINE THE PERIPHERY OF THE SCHOTTKY BARRIER, AND E. OXIDIZING THE EXPOSED SURFACE OF SAID GALLIUM ARSENIDE BODY AND SAID TANTALUM FILM.
Claim 2
Independent Claim
105 words
A METHOD OF FABRICATING A SCHOTTKY BARRIER ELECTRODE STRUCTURE ON A BODY OF GALLIUM ARSENIDE, COMPRISING THE STEPS OF A. CLEANING THE SURFACE OF SAID BODY, B. DEPOSITING A FILM OF TANTALUM ON A REGION OF SAID SURFACE BY EVAPORATING IN VACUUM IN THE ABSENCE OF WATER, WHILE MAINTAINING THE PRESSURE BELOW ABOUT 10**5 MM HG, TO A FILM THICKNESS OF ABOUT 2000A. C. DEPOSITING A GOLD FILM UPON SAID TANTALUM FILM, D. ETCHING THE EXPOSED SURFACE OF SAID GALLIUM ARSENIDE BODY TO DEFINE THE PERIPHERY OF THE SCHOTTKY BARRIER, AND E. OXIDIZING THE EXPOSED SURFACE OF SAID GALLIUM ARSENIDE BODY AND SAID TANTALUM FILM.
Claim 3
Dependent Claim
40 words
The method claimed in claim 1, wherein said step (e) comprises immersion of the structure in an oxidant solution long enough to produce an oxide film about 500A to about 1000A thick on said exposed surface of said gallium arsenide.
Claim 4
Dependent Claim
41 words
The method claimed in claim 1, further including the step of baking the structure in ambient gaseous oxidant at a temperature of about 250* to about 400*C for a period of about 1 hour, subsequent to said step (d) of etching.
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) | 1978-12-01 | 1979-06-02 | 1979-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-01 | 1983-06-02 | 1983-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-01 | 1987-06-02 | 1987-12-02 | $7700.00 | Window Closed / Lapsed |