US5811326A
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US
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Method for manufacturing thin film transistor
Assignee: Semiconductor Energy Laboratory Co Ltd
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Filing: 1995-01-17
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Granted: 1998-09-22
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Expires: 2015-01-17
Abstract
Abstract In a thin film transistor (TFT), a part of a surface or a whole surface of aluminum used as a gate electrode is covered by anodic oxide. In a process after anodization process, ultraviolet light is irradiated to a gate electrode in an oxidizing atmosphere containing oxygen, ozone, or nitrous oxide. Or, in a process after anodization process, a TFT is leaved (placed) in plasma in an oxidizing atmosphere. Or, ultraviolet light is irradiated to a gate electrode in plasma in an oxidizing atmosphere. A substrate temperature is a room temperature (50° C.) to 500° C., for example, 200° to 300° C. By ultraviolet light irradiation or plasma processing, metallic aluminum contained in anodic oxide is oxidized.
Inventors
- 👤 Mutsuo Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:14
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6324; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/031; H10D30/0312; H10D30/0314; H10D30/0321; H10D30/60; H10D30/67; H10D30/6704; H10D30/6713; H10D30/6715; H10D30/6729; H10D30/6737; H10D30/6739; H10D86/00; H10D86/40; H10D86/60; H10P14/6304; H10P14/6314; H10P14/65; H10P14/6516; H10P14/6529; H10P14/6536; H10P14/6538; H10D86/01; H10D86/021; H10P14/69; H10P14/692; H10P14/6938; H10P14/6939; H10P14/69391
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
86 words
A method for forming a thin film transistor comprising the steps of: forming a gate electrode comprising an anodizable metal on an active region formed on a substrate; anodizing the gate electrode, to form an anodic oxide film on at least side surfaces of the gate electrode, wherein a portion of said metal remains unoxidized within the anodic oxide film; irradiating ultraviolet light to the anodic oxide in an oxidizing atmosphere in order to oxidize said portion of said metal remaining in the anodic oxide film.
Claim 2
Independent Claim
86 words
A method for forming a thin film transistor comprising the steps of: forming a gate electrode comprising an anodizable metal on an active region formed on a substrate; anodizing the gate electrode, to form an anodic oxide film on at least side surfaces of the gate electrode, wherein a portion of said metal remains unoxidized within the anodic oxide film; irradiating ultraviolet light to the anodic oxide in an oxidizing atmosphere in order to oxidize said portion of said metal remaining in the anodic oxide film.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein a barrier type anodic oxide is formed in at least sides of the gate electrode.
Claim 4
Dependent Claim
15 words
The method of claim 1 wherein the oxidizing atmosphere has oxygen, ozone, or nitrous oxide.
Claim 5
Dependent Claim
17 words
The method of claim 1 wherein the ultraviolet light has a wavelentgh of 400 nm or less.
Claim 6
Independent Claim
92 words
A method for forming a thin film transistor comprising the steps of: forming a gate electrode comprising an anodizable metal over an active layer having impurity regions; and forming offset regions between the gate electrode and the impurity regions, wherein the offset region forming step comprises; anodizing the gate electrode to form anodic oxide, wherein a portion of said metal remains unoxidized within the anodic oxide; and irradiating ultraviolet light to the anodic oxide in an oxidizing atmosphere in order to oxidize said portion of said metal remaining in the anodic oxide.
Claim 7
Independent Claim
92 words
A method for forming a thin film transistor comprising the steps of: forming a gate electrode comprising an anodizable metal over an active layer having impurity regions; and forming offset regions between the gate electrode and the impurity regions, wherein the offset region forming step comprises; anodizing the gate electrode to form anodic oxide, wherein a portion of said metal remains unoxidized within the anodic oxide; and irradiating ultraviolet light to the anodic oxide in an oxidizing atmosphere in order to oxidize said portion of said metal remaining in the anodic oxide.
Claim 8
Dependent Claim
15 words
The method of claim 5 wherein the oxidizing atmosphere has oxygen, ozone, or nitrous oxide.
Claim 9
Dependent Claim
17 words
The method of claim 5 wherein the ultraviolet light has a wavelength of 400 nm or less.
Claim 10
Independent Claim
92 words
A method for forming a thin film transistor comprising the steps of: forming a gate electrode comprising an anodizable metal on an active region formed on a substrate; anodizing the gate electrode, to form anodic oxide comprising the anodizable metal oxide on at least sides of the gate electrode, wherein a portion of said metal remains unoxidized within the anodic oxide; and irradiating ultraviolet light to the gate electrode in an oxidizing atmosphere at 50° to 500° C. in order to oxidize said portion of said metal remaining in the anodic oxide.
Claim 11
Independent Claim
92 words
A method for forming a thin film transistor comprising the steps of: forming a gate electrode comprising an anodizable metal on an active region formed on a substrate; anodizing the gate electrode, to form anodic oxide comprising the anodizable metal oxide on at least sides of the gate electrode, wherein a portion of said metal remains unoxidized within the anodic oxide; and irradiating ultraviolet light to the gate electrode in an oxidizing atmosphere at 50° to 500° C. in order to oxidize said portion of said metal remaining in the anodic oxide.
Claim 12
Independent Claim
97 words
A method for forming a thin film transistor comprising the steps of: forming a gate electrode comprising an anodizable metal over an active layer having impurity regions; and forming offset regions between the gate electrode and the impurity regions, wherein the offset region forming step comprises, anodizing the gate electrode to form anodic oxide, wherein a portion of said metal remains unoxidized within the anodic oxide; and irradiating ultraviolet light to the anodic oxide in an oxidizing atmosphere at 50° to 500° C. in order to oxidize said portion of said metal remaining in the anodic oxide.
Claim 13
Independent Claim
97 words
A method for forming a thin film transistor comprising the steps of: forming a gate electrode comprising an anodizable metal over an active layer having impurity regions; and forming offset regions between the gate electrode and the impurity regions, wherein the offset region forming step comprises, anodizing the gate electrode to form anodic oxide, wherein a portion of said metal remains unoxidized within the anodic oxide; and irradiating ultraviolet light to the anodic oxide in an oxidizing atmosphere at 50° to 500° C. in order to oxidize said portion of said metal remaining in the anodic oxide.
Claim 14
Independent Claim
80 words
A method for forming a thin film transistor comprising the steps of: forming a gate electrode comprising an anodizable metal on an insulating film; anodizing the gate electrode, to form an anodic oxide film on at least side surfaces of the gate electrode, wherein a portion of said metal remains unoxidized within said anodic oxide film; and treating said anodic oxide in an oxidizing atmosphere in order to oxidize said portion of said metal remaining in said anodic oxide film.
Claim 15
Independent Claim
80 words
A method for forming a thin film transistor comprising the steps of: forming a gate electrode comprising an anodizable metal on an insulating film; anodizing the gate electrode, to form an anodic oxide film on at least side surfaces of the gate electrode, wherein a portion of said metal remains unoxidized within said anodic oxide film; and treating said anodic oxide in an oxidizing atmosphere in order to oxidize said portion of said metal remaining in said anodic oxide film.
Claim 16
Dependent Claim
11 words
The method of claim 1 wherein the gate electrode comprises aluminum.
Claim 17
Dependent Claim
11 words
The method of claim 5 wherein the gate electrode comprises aluminum.
Claim 18
Dependent Claim
11 words
The method of claim 8 wherein the gate electrode comprises aluminum.
Claim 19
Dependent Claim
11 words
The method of claim 9 wherein the gate electrode comprises aluminum.
Claim 20
Dependent Claim
11 words
The method of claim 10 wherein the gate electrode comprises aluminum.
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