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US5568288A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for forming thin film transistors with anodic oxide on sides of gate line

Assignee: Semiconductor Energy Laboratory Co Ltd
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Filing: 1993-11-16
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Granted: 1996-10-22
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Expires: 2013-11-16
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Abstract

Abstract An electro-optic device featuring an semiconductor device formed by providing an insulator over a gate electrode, and anodic oxidizing only the sides of the gate electrode.

Inventors

  • 👤 Shunpei Yamazaki
  • 👤 Akira Mase
  • 👤 Masaaki Hiroki

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 23:38
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/2007; G09G3/2011; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/136; G02F1/1362; G02F1/136227; G02F1/1368; G09G3/34; G09G3/36; G09G3/3611; G09G3/3648; G09G3/3674; G09G3/3677; G09G3/3685; G09G3/3688; G02F1/13624; G02F1/136245; G09G2300/00; G09G2300/08; G09G2300/0809; G09G2300/0823; G09G2310/00; G09G2310/02; G09G2310/0264; G09G2310/027; G09G2310/06; G09G2310/066; Y; Y10; Y10S; Y10S148/00; Y10S148/141

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 117 words
A method for forming a semiconductor device comprising the steps of: forming a semiconductor island including a channel region on a insulating surface; forming a gate insulating layer on said semiconductor island; forming a gate electrode having a side surface and a top surface on said gate insulating layer; forming an insulating film on the top surface of said gate electrode; and oxidizing only the side surface of said gate electrode by anodic oxidation; wherein said insulating film prevents said top surface from being oxidized by said anodic oxidation, introducing a dopant species into said semiconductor island with said gate electrode and oxidized side surface portion as a mask in order to form source and drain regions.
Claim 2
Independent Claim 117 words
A method for forming a semiconductor device comprising the steps of: forming a semiconductor island including a channel region on a insulating surface; forming a gate insulating layer on said semiconductor island; forming a gate electrode having a side surface and a top surface on said gate insulating layer; forming an insulating film on the top surface of said gate electrode; and oxidizing only the side surface of said gate electrode by anodic oxidation; wherein said insulating film prevents said top surface from being oxidized by said anodic oxidation, introducing a dopant species into said semiconductor island with said gate electrode and oxidized side surface portion as a mask in order to form source and drain regions.
Claim 3
Dependent Claim 14 words
The method of claim 1, wherein said insulating film includes a silicon oxide film.
Claim 4
Independent Claim 86 words
A method for manufacturing a semiconductor device comprising: forming a semiconductor island including a channel region on a insulating surface; forming a gate insulating layer on said semiconductor island; forming a gate electrode having a side surface and a top surface on said gate insulating layer; forming an insulating film on the top surface of said gate electrode; and oxidizing only the side surface of said gate electrode by anodic oxidation; wherein said insulating film prevents said top surface from being oxidized by said anodic oxidation.
Claim 5
Independent Claim 86 words
A method for manufacturing a semiconductor device comprising: forming a semiconductor island including a channel region on a insulating surface; forming a gate insulating layer on said semiconductor island; forming a gate electrode having a side surface and a top surface on said gate insulating layer; forming an insulating film on the top surface of said gate electrode; and oxidizing only the side surface of said gate electrode by anodic oxidation; wherein said insulating film prevents said top surface from being oxidized by said anodic oxidation.
Claim 6
Dependent Claim 14 words
The method of claim 3, wherein said insulating film includes a silicon oxide film.
Claim 7
Independent Claim 127 words
A method for manufacturing a semiconductor device comprising: forming at least one semiconductor island including at least a channel on a insulating surface; forming a gate insulating layer on at least said channel semiconductor region; forming a gate electrode having a side surface and a top surface on said gate insulating layer over said channel semiconductor region; forming an insulating film on the top surface of said gate electrode; oxidizing only the side surface of said gate electrode by anodic oxidation; wherein said insulating film prevents said top surface from being oxidized by said anodic oxidation, forming source and drain regions in said semiconductor island; forming a conductive layer on said semiconductor island; said conductive layer being connected to either one of said source and drain regions.
Claim 8
Independent Claim 127 words
A method for manufacturing a semiconductor device comprising: forming at least one semiconductor island including at least a channel on a insulating surface; forming a gate insulating layer on at least said channel semiconductor region; forming a gate electrode having a side surface and a top surface on said gate insulating layer over said channel semiconductor region; forming an insulating film on the top surface of said gate electrode; oxidizing only the side surface of said gate electrode by anodic oxidation; wherein said insulating film prevents said top surface from being oxidized by said anodic oxidation, forming source and drain regions in said semiconductor island; forming a conductive layer on said semiconductor island; said conductive layer being connected to either one of said source and drain regions.
Claim 9
Dependent Claim 14 words
The method of claim 5, wherein said insulating film includes a silicon oxide film.
Claim 10
Independent Claim 142 words
A method for forming a electro-optical device having a plurality of thin film transistors including at least one n-type of thin film transistor and at least one p-type of thin film transistor comprising: forming a plurality of semiconductor islands on a insulating surface, each semiconductor island including a channel region; forming a gate insulating layer on each semiconductor island; forming a gate electrode having a side surface and a top surface on each gate insulating layer; forming an insulating film on the top surface of each gate electrode; oxidizing only the side surface of said gate electrode by anodic oxidation; wherein said insulating film prevents said top surface from being oxidized by said anodic oxidation, introducing dopant species into each semiconductor island with said gate electrode and oxidized side surface portion as a mask in order to form source and drain regions.
Claim 11
Independent Claim 142 words
A method for forming a electro-optical device having a plurality of thin film transistors including at least one n-type of thin film transistor and at least one p-type of thin film transistor comprising: forming a plurality of semiconductor islands on a insulating surface, each semiconductor island including a channel region; forming a gate insulating layer on each semiconductor island; forming a gate electrode having a side surface and a top surface on each gate insulating layer; forming an insulating film on the top surface of each gate electrode; oxidizing only the side surface of said gate electrode by anodic oxidation; wherein said insulating film prevents said top surface from being oxidized by said anodic oxidation, introducing dopant species into each semiconductor island with said gate electrode and oxidized side surface portion as a mask in order to form source and drain regions.
Claim 12
Dependent Claim 14 words
The method of claim 7, wherein said insulating film includes a silicon oxide film.
Claim 13
Dependent Claim 62 words
The method of claim 7, further comprising the following steps: forming a conductive layer on each semiconductor island, said conductive layer being connected to either one of said source and drain regions; forming pixel electrodes on said insulating surface; said pixel electrodes being connected to either one of said source and drain regions of said n-type and p-type of thin film transistors.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1999-10-22 2000-04-22 2000-10-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2003-10-22 2004-04-22 2004-10-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2007-10-22 2008-04-22 2008-10-22 $7700.00 Window Closed / Lapsed

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