US4104672A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High power gallium arsenide schottky barrier field effect transistor
Assignee: AT&T Inc
•
Filing: 1976-10-29
•
Granted: 1978-08-01
•
Expires: 1996-10-29
Abstract
Abstract An integrated high-power gallium arsenide field-effect-transistor device for operation in the gigahertz range comprises a multiple-gate structure. The device, which features gate cross-under fingers, is fabricated in microminiature form by directly processing a wafer using electron-beam lithographic techniques.
Inventors
- 👤 James Vincent DiLorenzo
- 👤 Gerard Edward Mahoney
- 👤 Joseph Michael Moran
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:13
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/80; H10D30/87; H10D64/00; H10D64/20; H10D64/27; H10D64/311; H10D64/411; H10P; H10P50/00; H10P50/20
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
165 words
In combination in a high-power microminiature gallium arsenide field-effect-transistor device, a gallium arsenide substrate having an epitaxial mesa formed thereon, multiple interleaved source, gate and drain electrodes formed on said mesa, each of said electrodes including a portion that extends beyond one edge or the opposite edge of the mesa and onto said substrate, a drain bus bar on said substrate adjacent said one edge of said mesa connecting together said drain electrodes, a gate bus bar, including cross-under fingers, on said substrate adjacent the opposite edge of said mesa connecting together said gate electrodes, insulating portions disposed on selected regions of said cross-under fingers, and a source bus bar on said substrate adjacent said opposite edge of said mesa extending over the insulating portions on said cross-under fingers to connect together said source electrodes, wherein said cross-under fingers are respectively deposited in convex-bottom channels formed in said substrate, each of said fingers comprising, in order of deposition, layers of germanium/gold, silver, gold and tungsten.
Claim 2
Dependent Claim
165 words
In combination in a high-power microminiature gallium arsenide field-effect-transistor device, a gallium arsenide substrate having an epitaxial mesa formed thereon, multiple interleaved source, gate and drain electrodes formed on said mesa, each of said electrodes including a portion that extends beyond one edge or the opposite edge of the mesa and onto said substrate, a drain bus bar on said substrate adjacent said one edge of said mesa connecting together said drain electrodes, a gate bus bar, including cross-under fingers, on said substrate adjacent the opposite edge of said mesa connecting together said gate electrodes, insulating portions disposed on selected regions of said cross-under fingers, and a source bus bar on said substrate adjacent said opposite edge of said mesa extending over the insulating portions on said cross-under fingers to connect together said source electrodes, wherein said cross-under fingers are respectively deposited in convex-bottom channels formed in said substrate, each of said fingers comprising, in order of deposition, layers of germanium/gold, silver, gold and tungsten.
Claim 3
Dependent Claim
15 words
A combination as in claim 1 wherein said insulating portions are made of silicon dioxide.
Claim 4
Dependent Claim
164 words
A multiple-gate GaAs FET device comprising at least one mesa formed on a GaAs substrate member, plural interleaved source, drain and gate electrodes on each mesa with the ends of said electrodes extending onto said substrate member, a drain bus bar including at least one bonding pad on said substrate member, said drain bus bar electrically connecting together corresponding ends of said drain electrodes, a gate bus bar including at least one bonding pad on said substrate member and having cross-under members on said substrate member to electrically connect together corresponding ends of said gate electrodes, and a source bus bar including at least one bonding pad on said substrate member, said source bus bar crossing over said cross-under members and electrically insulated therefrom to electrically connect together corresponding ends of said source electrodes, wherein said cross-under members are respectively deposited in convex-bottom trenches formed in said substrate member, each of said members comprising, in order, deposited layers of germanium/gold, silver, gold and tungsten.
Claim 5
Dependent Claim
164 words
A multiple-gate GaAs FET device comprising at least one mesa formed on a GaAs substrate member, plural interleaved source, drain and gate electrodes on each mesa with the ends of said electrodes extending onto said substrate member, a drain bus bar including at least one bonding pad on said substrate member, said drain bus bar electrically connecting together corresponding ends of said drain electrodes, a gate bus bar including at least one bonding pad on said substrate member and having cross-under members on said substrate member to electrically connect together corresponding ends of said gate electrodes, and a source bus bar including at least one bonding pad on said substrate member, said source bus bar crossing over said cross-under members and electrically insulated therefrom to electrically connect together corresponding ends of said source electrodes, wherein said cross-under members are respectively deposited in convex-bottom trenches formed in said substrate member, each of said members comprising, in order, deposited layers of germanium/gold, silver, gold and tungsten.
Claim 6
Dependent Claim
29 words
A device as in claim 3 wherein a layer of silicon dioxide overlies said tungsten layer in those regions wherein said source bus bar crosses over said cross-under members.
References Cited (Backward Citations)
US3813585A
Cited
US3737743A
Cited
US3855613A
Cited
US3969745A
Cited
US4016643A
Cited
US4015278A
Cited
US3988619A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-31 | 1982-01-30 | 1982-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-31 | 1986-01-30 | 1986-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-31 | 1990-01-30 | 1990-08-01 | $7700.00 | Window Closed / Lapsed |