EP0055140A2
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EP
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Method of manufacturing a GaAs field effect transistor
Assignee: Toshiba Corp
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Filing: 1981-12-23
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Granted: —
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Expires: 2001-12-23
Abstract
Abstract A GaAs field effect transistor comprising a GaAs semi-conductor substrate (21) having an active layer (22), source and drain electrodes (23, 24), and a gate electrode (25), wherein the gate electrode (25) is embedded in the substrate (21) as a reaction layer (252) between GaAs and at least one metal (25) selected from Pt, Ti and Pa. A method of manufacturing a GaAs field effect transistor wherein a threshold voltage is controlled through the reaction of GaAs substrate (22) and at least one metal (251) selected from Pt, Ti and Pa.
Inventors
- 👤 Nobuyuki Toyoda
- 👤 Akimichi Hojo
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 02:19
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/061; H10D30/0612; H10D30/80; H10P; H10P95/00; H10P95/90; H10P95/904
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
81 words
A GaAs field effect transistor having a GaAs semiconductor substrate having an active layer, source and drain electrodes which are in ohmic contact with the active layer of the GaAs semiconductor substrate, and a gate electrode which is in-Schottky contact with the active layer, characterized in that the gate electrode comprises a compound layer which is produced in the active layer by chemical reaction between GaAs and at least one metal selected from the group consisting of platinum, titanium and palladium.
Claim 2
Dependent Claim
81 words
A GaAs field effect transistor having a GaAs semiconductor substrate having an active layer, source and drain electrodes which are in ohmic contact with the active layer of the GaAs semiconductor substrate, and a gate electrode which is in-Schottky contact with the active layer, characterized in that the gate electrode comprises a compound layer which is produced in the active layer by chemical reaction between GaAs and at least one metal selected from the group consisting of platinum, titanium and palladium.
Claim 3
Dependent Claim
23 words
A GaAs field effect transistor according to claim 1, characterized in that the gate electrode comprises a reacted compound of Pt and GaAs.
Claim 4
Dependent Claim
42 words
A GaAs field effect transistor according to claim 1, characterized in that a second metal layer of at least one metal selected from the group consisting of Mo, Ta, W and Cr is deposited as the gate electrode on the compound layer.
Claim 5
Dependent Claim
30 words
A GaAs field effect transistor according to claim 3, characterized in that a third metal layer is deposited on the second metal layer directly or with another metal interposed therebetween.
Claim 6
Dependent Claim
17 words
A GaAs field effect transistor according to claim 4, characterized in that the third metal comprises Au.
Claim 7
Independent Claim
78 words
A method for manufacturing a GaAs field effect transistor comprising the steps of forming a first metal layer by depositing on a surface of an active layer formed on a GaAs substrate at least one metal selected from the group consisting of platinum, titanium and palladium, and forming a compound layer within an active layer by reacting GaAs and the metal through a heating treatment so that a threshold voltage of the GaAs field effect transistor is controlled.
Claim 8
Independent Claim
78 words
A method for manufacturing a GaAs field effect transistor comprising the steps of forming a first metal layer by depositing on a surface of an active layer formed on a GaAs substrate at least one metal selected from the group consisting of platinum, titanium and palladium, and forming a compound layer within an active layer by reacting GaAs and the metal through a heating treatment so that a threshold voltage of the GaAs field effect transistor is controlled.
Claim 9
Dependent Claim
32 words
A method according to claim 6, characterized in that an annealing time is controlled to change the thickness of the compound layer which is produced so that the threshold voltage is controlled.
Claim 10
Dependent Claim
20 words
A method according to claim 6, characterized in that the annealing is performed after interconnect metalization between elements is completed.
Claim 11
Dependent Claim
21 words
A method according to claim 6, 7 or 9, characterized in that the metal which is deposited reacts completely with GaAs.
Claim 12
Dependent Claim
28 words
A method according to claim 10, characterized in that the amount of the metal which is deposited is the minimum amount necessary to control a desired threshold voltage.
Claim 13
Dependent Claim
60 words
A method according to claim 6, 7 or 9, characterized in that a second metal layer of at least one metal selected from the group consisting of Mo, Ta, W and Cr, is deposited after the first metal layer is formed, and annealing is performed to react the first metal and the GaAs so that the threshold voltage is controlled.
Claim 14
Dependent Claim
46 words
A method according to claim 12, characterized in that a third metal layer is deposited for bonding wiring layers after the second metal layer is deposited, and annealing is performed to react the first metal layer with the GaAs so that the threshold voltage is controlled.
References Cited (Backward Citations)
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