Patent US6593193B2 successfully refreshed from Google Patents.
US6593193B2
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US
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Semiconductor device and method for fabricating the same
Assignee: Panasonic Holdings Corp
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Filing: 2002-01-25
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Granted: 2003-07-15
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Expires: 2022-01-25
Abstract
Abstract An insulating-gate semiconductor device has a first nitride semiconductor layer formed over a substrate and an insulating oxidation layer obtained by oxidizing a second nitride semiconductor layer formed on the first nitride semiconductor layer. A gate electrode is formed on the insulating oxidation layer.
Inventors
- 👤 Katsunori Nishii
- 👤 Kaoru Inoue
- 👤 Toshinobu Matsuno
- 👤 Yoshito Ikeda
- 👤 Hiroyuki Masato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:29
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/015; H10D30/40; H10D30/47; H10D30/471; H10D30/473; H10D30/4732; H10D64/00; H10D64/01; H10D64/013; H10D64/01358; H10D62/00; H10D62/80; H10D62/85; H10D62/8503
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
118 words
A method for fabricating a semiconductor device, the method comprising: a first step of forming a first nitride semiconductor layer over a substrate; a second step of forming a second nitride semiconductor layer on the first nitride semiconductor layer and oxidizing the formed second nitride semiconductor layer to form an insulating oxidation layer composed of the second nitride semiconductor layer; a third step of forming a gate electrode on the insulating oxidation layer; and a fourth step of performing selective etching with respect to regions of the insulating oxidation layer which are located on both sides of the gate electrode to form openings in the insulating oxidation layer and forming source and drain electrodes in the formed openings.
Claim 2
Independent Claim
118 words
A method for fabricating a semiconductor device, the method comprising: a first step of forming a first nitride semiconductor layer over a substrate; a second step of forming a second nitride semiconductor layer on the first nitride semiconductor layer and oxidizing the formed second nitride semiconductor layer to form an insulating oxidation layer composed of the second nitride semiconductor layer; a third step of forming a gate electrode on the insulating oxidation layer; and a fourth step of performing selective etching with respect to regions of the insulating oxidation layer which are located on both sides of the gate electrode to form openings in the insulating oxidation layer and forming source and drain electrodes in the formed openings.
Claim 3
Dependent Claim
28 words
The method of claim 1 , wherein an oxidation rate for the first nitride semiconductor layer is lower than an oxidation rate for the second nitride semiconductor layer.
Claim 4
Dependent Claim
22 words
The method of claim 1 , wherein each of the first and second nitride semiconductor layers is composed of the same material.
Claim 5
Dependent Claim
41 words
The method of claim 1 , further comprising, prior to the first step, the step of: forming, on the substrate, an active layer composed of a third nitride semiconductor having an energy gap smaller than in the first nitride semiconductor layer.
Claim 6
Dependent Claim
48 words
The method of claim 1 , further comprising, between the first and second steps, the step of: forming, on the first nitride semiconductor layer, an anti-oxidation layer composed of a fourth nitride semiconductor having an oxidation rate lower than an oxidation rate for the second nitride semiconductor layer.
Claim 7
Dependent Claim
12 words
The method of claim 5 , wherein the anti-oxidation layer contains aluminum.
Claim 8
Dependent Claim
52 words
The method of claim 1 , further comprising, between the second and third steps, the step of: forming an insulating film on the insulating oxidation layer, wherein the fourth step includes the step of: forming openings also in regions of the insulating film to be formed with the source and drain electrodes.
Claim 9
Dependent Claim
22 words
The method of claim 7 , wherein the insulating film is composed of a silicon oxide film or a silicon nitride film.
Claim 10
Dependent Claim
77 words
The method of claim 1 , wherein the second step includes the steps of: forming the insulating oxidation layer on at least a region of the second nitride semiconductor layer to be formed with the gate electrode; and selectively oxidizing a region between the gate-electrode formation region and a region to be formed with the drain electrode to form the insulating oxidation layer with a thicker portion which is larger in thickness than the insulating oxidation layer.
Claim 11
Dependent Claim
14 words
The method of claim 1 , wherein the first nitride semiconductor layer contains aluminum.
Claim 12
Independent Claim
135 words
A method for fabricating a semiconductor device, the method comprising: a first step of forming a first nitride semiconductor layer over a substrate; a second step of forming a second nitride semiconductor layer on the first nitride semiconductor layer; a third step of forming an anti-oxidation protective film on regions of the second nitride semiconductor layer to be formed with ohmic electrodes; a fourth step of oxidizing the second nitride semiconductor layer by using the anti-oxidation protective film as a mask to form an insulating oxidation layer in the second nitride semiconductor layer except for the ohmic-electrode formation regions; a fifth step of removing the anti-oxidation protective film and forming the ohmic electrodes on the ohmic-electrode formation regions of the second nitride semiconductor layer; and selectively forming a gate electrode on the insulating oxidation layer.
Claim 13
Independent Claim
135 words
A method for fabricating a semiconductor device, the method comprising: a first step of forming a first nitride semiconductor layer over a substrate; a second step of forming a second nitride semiconductor layer on the first nitride semiconductor layer; a third step of forming an anti-oxidation protective film on regions of the second nitride semiconductor layer to be formed with ohmic electrodes; a fourth step of oxidizing the second nitride semiconductor layer by using the anti-oxidation protective film as a mask to form an insulating oxidation layer in the second nitride semiconductor layer except for the ohmic-electrode formation regions; a fifth step of removing the anti-oxidation protective film and forming the ohmic electrodes on the ohmic-electrode formation regions of the second nitride semiconductor layer; and selectively forming a gate electrode on the insulating oxidation layer.
Claim 14
Dependent Claim
15 words
The method of claim 11 , wherein the anti-oxidation protective film is composed of silicon.
Claim 15
Dependent Claim
15 words
The method of claim 11 , wherein the anti-oxidation protective film is an insulating film.
Claim 16
Dependent Claim
91 words
The method of claim 11 , further comprising, between the second and third steps, the steps of: forming, on the second nitride semiconductor layer, a protective film covering a region of the second nitride semiconductor layer to be formed with a device; and oxidizing the first and second nitride semiconductor layers by using the formed protective film as a mask to form an isolation film in a peripheral portion of the device formation region, wherein the third step includes the step of: forming the anti-oxidation protective film from the protective film.
Claim 17
Dependent Claim
41 words
The method of claim 11 , further comprising, prior to the first step, the step of: forming, on the substrate, an active layer composed of a third nitride semiconductor having an energy gap smaller than in the first nitride semiconductor layer.
Claim 18
Dependent Claim
48 words
The method of claim 11 , further comprising, between the first and second steps, the step of: forming, on the first nitride semiconductor layer, an anti-oxidation layer composed of a fourth nitride semiconductor having an oxidation rate lower than an oxidation rate for the second nitride semiconductor layer.
Claim 19
Dependent Claim
12 words
The method of claim 16 , wherein the anti-oxidation layer contains aluminum.
Claim 20
Dependent Claim
14 words
The method of claim 11 , wherein the first nitride semiconductor layer contains aluminum.
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