EP0176754A1
Expired / Lapsed
EP
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Schottky-gate field effect transistor
Assignee: Sumitomo Electric Industries Ltd
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Filing: 1985-08-26
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Granted: —
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Expires: 2005-08-26
Abstract
Abstract @ A Schottky-gate field effect transistor comprises a semi-insulative semiconductor substrate (10), an active layer (12) formed on one surface of the substrate, a source electrode (16) and a drain electrode (14) on the active layer in ohmic contact thereto, respectively, a first Schottky gate electrode (18) on the active layer between the source and drain electrodes, and a second Schottky gate electrode (20) on the active layer between the drain electrode and the first gate electrode. A portion of the active layer underneath the second gate electrode has a sheet resistance smaller than that of the active layer portion underneath the first gate electrode. The source electrode and the second gate electrode are electrically interconnected by connection means (22) formed on the substrate.
Inventors
- 👤 Tomihiro c/o Osaka Works Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 14:47
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/10; H10D62/17; H10D62/213; H10D62/221; H10D30/00; H10D30/80; H10D30/87; H10D30/873; H10D64/00; H10D64/20; H10D64/27; H10D64/311; H10D64/411
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
117 words
A Schottky-gate field effect transistor comprising a semi-insulative semiconductor substrate, an active layer formed on one surface of the substrate, a source electrode and a drain electrode on the active layer in ohmic contact thereto, respectively, a first Schottky gate electrode on the active layer between the source and drain electrodes, and a second Schottky gate electrode on the active layer between the drain electrode and the first gate electrode, a portion of the active layer underneath the second gate electrode having a sheet resistance smaller than that of the active layer portion underneath the first gate electrode, and the source electrode and the second gate electrode being electrically interconnected by connection means formed on the substrate.
Claim 2
Dependent Claim
117 words
A Schottky-gate field effect transistor comprising a semi-insulative semiconductor substrate, an active layer formed on one surface of the substrate, a source electrode and a drain electrode on the active layer in ohmic contact thereto, respectively, a first Schottky gate electrode on the active layer between the source and drain electrodes, and a second Schottky gate electrode on the active layer between the drain electrode and the first gate electrode, a portion of the active layer underneath the second gate electrode having a sheet resistance smaller than that of the active layer portion underneath the first gate electrode, and the source electrode and the second gate electrode being electrically interconnected by connection means formed on the substrate.
Claim 3
Dependent Claim
36 words
A field effect transistor as claimed in Claim 1 wherein the active layer portion underneath the second gate electrode has a impurity concentration higher than that of the active layer portion underneath the first gate electrode.
Claim 4
Dependent Claim
60 words
A field effect transistor as claimed in Claim 2 wherein the active layer portion underneath the first gate electrode is doped with impurities to have the threshold voltage of about 1.5 V, and the active layer portion underneath the second gate electrode has the dose larger than that of the active layer portion underneath the first gate electrode about 20%.
Claim 5
Dependent Claim
46 words
A field effect transistor as claimed in Claim 3 wherein the active layer portion underneath the first gate electrode has the dose of 3.9X10 12 /cm 2 and the active layer portion underneath the second gate electrode has the dose of 5.0×10 12 /cm 2 .
Claim 6
Dependent Claim
23 words
A field effect transistor as claimed in Claim 4 wherein the substrate and the active layer are made from III-V compound semiconductor material.
Claim 7
Dependent Claim
25 words
A field effect transistor as claimed in Claim 5 wherein the substrate is made from GaAs and the active layer is doped with n-type impurities.
Claim 8
Dependent Claim
35 words
A field effect transistor as claimed in Claim 1 wherein the active layer portion underneath the first gate electrode has a thickness smaller than that of the active layer portion underneath the second gate electrode.
Claim 9
Dependent Claim
53 words
A field effect transistor as claimed in Claim 7 wherein the active layer portion underneath the first gate electrode has the threshold voltage of about 1.5 V and the active layer portion underneath the second gate electrode is thicker than that of the active layer portion underneath the first gate electrode about 20%.
Claim 10
Dependent Claim
23 words
A field effect transistor as claimed in Claim 8 wherein the substrate and the active layer are made from III-V compound semiconductor material.
Claim 11
Dependent Claim
25 words
A field effect transistor as claimed in Claim 9 wherein the substrate is made from GaAs and the active layer is doped with n-type impurities.
References Cited (Backward Citations)
US3872491A
Cited
US4389660A
Cited
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