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US5719065A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for manufacturing semiconductor device with removable spacers

Assignee: Semiconductor Energy Laboratory Co Ltd
•
Filing: 1994-09-28
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Granted: 1998-02-17
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Expires: 2014-09-28
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Abstract

Abstract A thin film transistor of the present invention has an active layer including at least source, drain and channel regions formed on an insulating surface. A high resistivity region is formed between the channel region and each of the source and drain regions. A film capable of trapping positive charges therein is provided on at least the high resistivity region so that N-type conductivity is induced in the high resistivity region. Accordingly, the reliability of N-channel type TFT against hot electrons can be improved.

Inventors

  • 👤 Yasuhiko Takemura
  • 👤 Satoshi Teramoto

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 21:18
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D30/67; H10D30/674; H10D30/6755; H10D30/01; H10D30/021; H10D30/0223; H10D30/0227; H10D30/031; H10D30/0312; H10D30/0314; H10D30/0321; H10D30/601; H10D30/6704; H10D30/6713; H10D30/6715; H10D30/6757; H10D64/00; H10D64/01; H10D64/025; H10D64/027; H10D86/00; H10D86/40; H10D86/451; H10D86/481; H10D86/60; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P95/00; H10P95/90; H10D30/6721

Claims Analysis

Total Claims: 21
Claim 1
Independent Claim 137 words
A method for manufacturing a semiconductor device comprising the steps of: forming an active semiconductor layer including at least source, drain and channel regions on an insulating surface; forming an insulating film on said active semiconductor layer; forming a gate electrode on said insulating film; subjecting said gate electrode to anodization in an electrolyte in order to form an oxide of said gate electrode on at least a side surface thereof; etching at least a part of said insulating film using said oxide as a mask, thereby forming a gate insulating film; removing said oxide formed on the side surface of said gate electrode to expose a portion of said gate insulating film; and then forming a film capable of trapping positive ions therein on said gate electrode and the exposed portion of said gate insulating film.
Claim 2
Independent Claim 137 words
A method for manufacturing a semiconductor device comprising the steps of: forming an active semiconductor layer including at least source, drain and channel regions on an insulating surface; forming an insulating film on said active semiconductor layer; forming a gate electrode on said insulating film; subjecting said gate electrode to anodization in an electrolyte in order to form an oxide of said gate electrode on at least a side surface thereof; etching at least a part of said insulating film using said oxide as a mask, thereby forming a gate insulating film; removing said oxide formed on the side surface of said gate electrode to expose a portion of said gate insulating film; and then forming a film capable of trapping positive ions therein on said gate electrode and the exposed portion of said gate insulating film.
Claim 3
Dependent Claim 26 words
The method of claim 1 further comprising forming a barrier type anodic oxide film on said gate electrode after said subjecting step but before said etching.
Claim 4
Dependent Claim 32 words
The method of claim 1 further comprising the step of introducing an impurity ion into a portion of said active layer with said gate electrode used as a mask after said etching.
Claim 5
Dependent Claim 21 words
The method of claim of claim 3 further comprising the step of activating said impurity ion introduced into said active layer.
Claim 6
Dependent Claim 37 words
The method of claim 1 further comprising introducing hydrogen by ion doping into a portion between said channel and said source and between said channel and said drain at a concentration 0.01 to 10 atoms/cm 3 .
Claim 7
Dependent Claim 21 words
The method of claim 5 further comprising the step of annealing said active layer at 200°-400° C. after introducing said hydrogen.
Claim 8
Independent Claim 216 words
A method for manufacturing a semiconductor device comprising the steps of: forming a crystalline semiconductor layer on an insulating surface; forming an insulating fill comprising silicon oxide on said crystalline semiconductor layer; forming a gate electrode on said insulating film; subjecting said gate electrode to anodization in an electrolyte in order to form an oxide of said gate electrode on at least a side surface thereof; etching at least a part of said insulating film using said oxide as a mask, thereby forming a gate insulating film; after said etching, removing said oxide formed on the side surface of said gate electrode to expose a portion of said gate insulating film; after said removing, selectively introducing impurity ions into said semiconductor layer for giving one conductivity type thereto with said gate electrode and said gate insulating film as a mask wherein portions of said semiconductor layer which extend beyond said oxide are doped with said impurity ions at a first concentration and portions of said semiconductor layer which are positioned below the exposed portion of the gate insulating film are doped with said impurity ions at a second concentration smaller than said first concentration; and forming a film comprising silicon nitride at least on said gate electrode and the exposed portion of said gate insulating film.
Claim 9
Independent Claim 216 words
A method for manufacturing a semiconductor device comprising the steps of: forming a crystalline semiconductor layer on an insulating surface; forming an insulating fill comprising silicon oxide on said crystalline semiconductor layer; forming a gate electrode on said insulating film; subjecting said gate electrode to anodization in an electrolyte in order to form an oxide of said gate electrode on at least a side surface thereof; etching at least a part of said insulating film using said oxide as a mask, thereby forming a gate insulating film; after said etching, removing said oxide formed on the side surface of said gate electrode to expose a portion of said gate insulating film; after said removing, selectively introducing impurity ions into said semiconductor layer for giving one conductivity type thereto with said gate electrode and said gate insulating film as a mask wherein portions of said semiconductor layer which extend beyond said oxide are doped with said impurity ions at a first concentration and portions of said semiconductor layer which are positioned below the exposed portion of the gate insulating film are doped with said impurity ions at a second concentration smaller than said first concentration; and forming a film comprising silicon nitride at least on said gate electrode and the exposed portion of said gate insulating film.
Claim 10
Dependent Claim 26 words
The method of claim 7 further comprising forming a barrier type anodic oxide film on said gate electrode after said subjecting step but before said etching.
Claim 11
Dependent Claim 32 words
The method of claim 7 where said first concentration is from 1×10 20 to 2×10 21 atoms/cm 3 and said second concentration is from 1×10 17 to 2×10 18 atoms/cm 3 .
Claim 12
Independent Claim 256 words
A method for manufacturing a semiconductor device comprising the steps of: forming a crystalline semiconductor layer on an insulating surface; forming an insulating film comprising silicon oxide on said crystalline semiconductor layer; forming a gate electrode on said insulating film; subjecting said gate electrode to anodization in an electrolyte in order to form an oxide of said gate electrode on at least a side surface thereof; selectively etching said insulating film using said oxide as a mask to define a gate insulating film, thereby, exposing first portions of said semiconductor which extends beyond said oxide; after said etching, removing said oxide formed on the side surface of said gate electrode to expose a portion of said gate insulating film; after said removing, selectively introducing impurity ions into said semiconductor layer for giving one conductivity type thereto with said gate electrode and said gate insulating film as a mask wherein said first portions of said semiconductor layer are doped with said impurity ions at a first concentration and portions of said semiconductor layer which are positioned below the exposed portion of the gate insulating film are doped with said impurity ions at a second concentration smaller than said first concentration; forming a metal film on said first portions of said semiconductor layer; reacting said metal film with said first portions of said semiconductor layer to increase the conductivity of said first portions; and forming a film capable of trapping positive ions therein at least on said gate electrode and the exposed portion of said gate insulating film.
Claim 13
Independent Claim 256 words
A method for manufacturing a semiconductor device comprising the steps of: forming a crystalline semiconductor layer on an insulating surface; forming an insulating film comprising silicon oxide on said crystalline semiconductor layer; forming a gate electrode on said insulating film; subjecting said gate electrode to anodization in an electrolyte in order to form an oxide of said gate electrode on at least a side surface thereof; selectively etching said insulating film using said oxide as a mask to define a gate insulating film, thereby, exposing first portions of said semiconductor which extends beyond said oxide; after said etching, removing said oxide formed on the side surface of said gate electrode to expose a portion of said gate insulating film; after said removing, selectively introducing impurity ions into said semiconductor layer for giving one conductivity type thereto with said gate electrode and said gate insulating film as a mask wherein said first portions of said semiconductor layer are doped with said impurity ions at a first concentration and portions of said semiconductor layer which are positioned below the exposed portion of the gate insulating film are doped with said impurity ions at a second concentration smaller than said first concentration; forming a metal film on said first portions of said semiconductor layer; reacting said metal film with said first portions of said semiconductor layer to increase the conductivity of said first portions; and forming a film capable of trapping positive ions therein at least on said gate electrode and the exposed portion of said gate insulating film.
Claim 14
Dependent Claim 26 words
The method of claim 10 further comprising forming a barrier type anodic oxide film on said gate electrode after said subjecting step but before said etching.
Claim 15
Independent Claim 138 words
A method for manufacturing a semiconductor device comprising the steps of: forming a crystalline semiconductor layer on an insulating surface; forming an insulating film on said crystalline semiconductor layer; forming a gate electrode on said insulating film; subjecting said gate electrode to anodization in an electrolyte in order to form an oxide of said gate electrode on at least a side surface thereof; etching at least a part of said insulating film using said oxide as a mask, thereby forming a gate insulating film; after said etching, removing said oxide formed on the side surface of said gate electrode to expose a portion of said gate insulating film; and forming a film comprising silicon nitride with a thickness from 200 to 2000 Å at least on said gate electrode and the exposed portion of said gate insulating film.
Claim 16
Independent Claim 138 words
A method for manufacturing a semiconductor device comprising the steps of: forming a crystalline semiconductor layer on an insulating surface; forming an insulating film on said crystalline semiconductor layer; forming a gate electrode on said insulating film; subjecting said gate electrode to anodization in an electrolyte in order to form an oxide of said gate electrode on at least a side surface thereof; etching at least a part of said insulating film using said oxide as a mask, thereby forming a gate insulating film; after said etching, removing said oxide formed on the side surface of said gate electrode to expose a portion of said gate insulating film; and forming a film comprising silicon nitride with a thickness from 200 to 2000 Å at least on said gate electrode and the exposed portion of said gate insulating film.
Claim 17
Dependent Claim 90 words
The method of claim 12 further comprising a step of, after said removing, selectively introducing impurity ions into said semiconductor layer for giving one conductivity type thereto with said gate electrode and said gate insulating film as a mask wherein said first portions of said semiconductor layer are doped with said impurity ions at a first concentration and portions of said semiconductor layer which are positioned below the exposed portion of the gate insulating film are doped with said impurity ions at a second concentration smaller than said first concentration.
Claim 18
Dependent Claim 27 words
The method of claim 12 further comprising forming a barrier type anodic oxide film on said gate electrode after said subjecting step but before said etching step.
Claim 19
Independent Claim 173 words
A method for manufacturing a semiconductor device comprising the steps of: forming a crystalline semiconductor layer on an insulating surface; forming an insulating film comprising silicon oxide on said crystalline semiconductor layer; forming a gate electrode on said insulating film; forming masks on side surfaces of said gate electrode where said insulating film has portions uncovered by said masks; etching the uncovered portions of said insulating film to define a gate insulating film; after said etching, removing said masks to expose a portion of said gate insulating film; and forming a first pair of impurity regions in portions of said semiconductor layer which extend beyond said masks and a second pair of impurity regions in portions of said semiconductor layer which are positioned below the exposed portion of the gate insulating film where said first pair of impurity regions are doped with impurity ions for giving one conductivity at a first concentration and said second pair of impurity regions are doped with impurity ion at a second concentration smaller than said first concentration.
Claim 20
Independent Claim 173 words
A method for manufacturing a semiconductor device comprising the steps of: forming a crystalline semiconductor layer on an insulating surface; forming an insulating film comprising silicon oxide on said crystalline semiconductor layer; forming a gate electrode on said insulating film; forming masks on side surfaces of said gate electrode where said insulating film has portions uncovered by said masks; etching the uncovered portions of said insulating film to define a gate insulating film; after said etching, removing said masks to expose a portion of said gate insulating film; and forming a first pair of impurity regions in portions of said semiconductor layer which extend beyond said masks and a second pair of impurity regions in portions of said semiconductor layer which are positioned below the exposed portion of the gate insulating film where said first pair of impurity regions are doped with impurity ions for giving one conductivity at a first concentration and said second pair of impurity regions are doped with impurity ion at a second concentration smaller than said first concentration.
Claim 21
Dependent Claim 35 words
The method of claim 15 further comprising forming a film comprising silicon nitride with a thickness 200 to 2000 Å at least on said gate electrode and the exposed portion of said gate insulating film.

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2001-02-16 2001-08-18 2002-02-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-02-16 2005-08-18 2006-02-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-02-16 2009-08-18 2010-02-17 $7700.00 Window Closed / Lapsed

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