Patent US3643922A successfully refreshed from Google Patents.
US5814540A
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Method for producing a transistor
Assignee: Semiconductor Energy Laboratory Co Ltd
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Filing: 1997-01-17
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Granted: 1998-09-29
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Expires: 2017-01-17
Abstract
Abstract In a thin film transistor, the reliability, yield and characteristics are improved by preventing the wire breaking of gate electrodes and wirings and the breakdown of a gate insulating film. Materials having at least one element of nickel, iron, cobalt and platinum are selectively formed closely on or beneath an amorphous silicon thin film formed on a substrate, and the materials are selectively crystallized, and the crystallized regions thus obtained are used as a channel forming region and impurity regions of a thin film transistor, and further an isolation between the thin film transistors is performed by the uncrystallized region.
Inventors
- 👤 Yasuhiko Takemura
- 👤 Toru Takayama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:18
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D30/67; H10D86/00; H10D86/01; H10D86/021; H10D86/0221; H10D86/0223; H10D86/0225; H10D86/40; H10D86/481; H10D86/60
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
101 words
A method for producing a semiconductor device comprising the steps of: forming a base film on a substrate; forming a semiconductor film comprising silicon on the base film; selectively forming a material comprising at least one element selected from the group consisting of nickel, iron, cobalt and platinum in contact with the semiconductor film; and annealing the semiconductor film by heating in a reducing atmosphere to crystallize it using the element after said selectively forming step; wherein a portion of the semiconductor film is not crystallized by the annealing step and insulates from crystallized portions of the semiconductor film each other.
Claim 2
Independent Claim
101 words
A method for producing a semiconductor device comprising the steps of: forming a base film on a substrate; forming a semiconductor film comprising silicon on the base film; selectively forming a material comprising at least one element selected from the group consisting of nickel, iron, cobalt and platinum in contact with the semiconductor film; and annealing the semiconductor film by heating in a reducing atmosphere to crystallize it using the element after said selectively forming step; wherein a portion of the semiconductor film is not crystallized by the annealing step and insulates from crystallized portions of the semiconductor film each other.
Claim 3
Dependent Claim
20 words
The method of claim 1 wherein said annealing step is carried out at a temperature of 400° to 580° C.
Claim 4
Dependent Claim
16 words
The method of claim 1 wherein the base film is formed on the substrate by sputtering.
Claim 5
Independent Claim
85 words
A method for producing a semiconductor device comprising the steps of: forming a semiconductor film comprising silicon on a substrate; forming a material comprising at least one element selected from the group consisting of nickel, iron, cobalt and platinum in contact with the semiconductor film; and heating the semiconductor film in a reducing atmosphere to crystallize it using the element, wherein a portion of the semiconductor film is not crystallized by the heating step and insulates from crystallized portions of the semiconductor film each other.
Claim 6
Independent Claim
85 words
A method for producing a semiconductor device comprising the steps of: forming a semiconductor film comprising silicon on a substrate; forming a material comprising at least one element selected from the group consisting of nickel, iron, cobalt and platinum in contact with the semiconductor film; and heating the semiconductor film in a reducing atmosphere to crystallize it using the element, wherein a portion of the semiconductor film is not crystallized by the heating step and insulates from crystallized portions of the semiconductor film each other.
Claim 7
Independent Claim
92 words
A method for producing a semiconductor device comprising the steps of: forming a base film on a substrate by sputtering; forming a semiconductor film comprising silicon on the base film; selectively forming a material comprising at least one element selected from the group consisting of nickel, iron, cobalt and platinum in contact with the semiconductor film; and heating the semiconductor film to crystallize it using the element, wherein a portion of the semiconductor film is not crystallized by the heating step and insulates from crystallized portions of the semiconductor film each other.
Claim 8
Independent Claim
92 words
A method for producing a semiconductor device comprising the steps of: forming a base film on a substrate by sputtering; forming a semiconductor film comprising silicon on the base film; selectively forming a material comprising at least one element selected from the group consisting of nickel, iron, cobalt and platinum in contact with the semiconductor film; and heating the semiconductor film to crystallize it using the element, wherein a portion of the semiconductor film is not crystallized by the heating step and insulates from crystallized portions of the semiconductor film each other.
References Cited (Backward Citations)
US5313075A
Cited
US5147826A
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US5236850A
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US5289030A
Cited
US5403772A
Cited
US5275851A
Cited
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| 3.5 Years (Year 4) | 2001-09-28 | 2002-03-30 | 2002-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-09-28 | 2006-03-30 | 2006-09-29 | $3760.00 | Window Closed / Lapsed |
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