US5977559A
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Thin-film transistor having a catalyst element in its active regions
Assignee: Semiconductor Energy Laboratory Co Ltd
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Filing: 1998-03-26
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Granted: 1999-11-02
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Expires: 2018-03-26
Abstract
Abstract A thin-film transistor (TFT) which has a crystalline silicon active layer of excellent reliability and characteristics, and a method of fabricating such a TFT inexpensively are provided. In a TFT which has at least two low density impurity regions and a source/drain adjacent to a channel-forming region, catalyst elements which cause amorphous silicon to crystallize are included in the source/drain, and the density of said catalyst elements in the interface between the channel-forming region and the low-density impurity regions is less than that in the source/drain.
Inventors
- 👤 Hongyong Zhang
- 👤 Toru Takayama
- 👤 Yasuhiko Takemura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 02:24
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/031; H10D30/0312; H10D30/0314; H10D30/0321; H10D30/60; H10D30/67; H10D30/6729; H10D30/673; H10D30/6731; H10D30/674; H10D30/6741; H10D30/6743; H10D30/6745; H10D30/6704; H10D30/6713; H10D30/6715; H10P; H10P14/00; H10P14/20; H10P14/29; H10P14/2901; H10P14/2921; H10P14/2922; H10P14/32; H10P14/3202; H10P14/3238; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P14/38; H10P14/3802; H10P14/3806; H10P14/3808; H10P14/3814; H10P14/3816
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
98 words
A thin film transistor comprising: a source region, a drain region and a channel-forming region which comprise crystalline silicon and are provided on an insulating surface, said channel-forming region being provided between said source region and said drain region, wherein said source region and said drain region contain a catalyst element, and density of said catalyst element within said source region and said drain region exceeds 1×10 17 atoms/cm 3 , and wherein said channel-forming region contains a catalyst element, and density of said catalyst element in said channel-forming region is less than 1×10 17 atoms/cm 3 .
Claim 2
Dependent Claim
98 words
A thin film transistor comprising: a source region, a drain region and a channel-forming region which comprise crystalline silicon and are provided on an insulating surface, said channel-forming region being provided between said source region and said drain region, wherein said source region and said drain region contain a catalyst element, and density of said catalyst element within said source region and said drain region exceeds 1×10 17 atoms/cm 3 , and wherein said channel-forming region contains a catalyst element, and density of said catalyst element in said channel-forming region is less than 1×10 17 atoms/cm 3 .
Claim 3
Dependent Claim
22 words
The transistor of claim 1 wherein said catalyst element is at least one element selected from nickel, iron, cobalt, palladium and platinum.
Claim 4
Dependent Claim
122 words
A thin film transistor comprising: a source region, a drain region and a channel-forming region which comprise crystalline silicon and are provided on an insulating surface, said channel-forming region being provided between said source region and said drain region; a gate insulating film provided on said channel-forming region; and a gate electrode provided on said gate insulating film, wherein said source region and said drain region contain a catalyst element, and a density of said catalyst element within said source region and said drain region exceeds 1×10 17 atoms/cm 3 , and wherein said channel-forming region contains the same element as said catalyst element, and density of said catalyst element in said channel-forming region is less than 1×10 17 atoms/cm 3 .
Claim 5
Dependent Claim
122 words
A thin film transistor comprising: a source region, a drain region and a channel-forming region which comprise crystalline silicon and are provided on an insulating surface, said channel-forming region being provided between said source region and said drain region; a gate insulating film provided on said channel-forming region; and a gate electrode provided on said gate insulating film, wherein said source region and said drain region contain a catalyst element, and a density of said catalyst element within said source region and said drain region exceeds 1×10 17 atoms/cm 3 , and wherein said channel-forming region contains the same element as said catalyst element, and density of said catalyst element in said channel-forming region is less than 1×10 17 atoms/cm 3 .
Claim 6
Dependent Claim
22 words
The transistor of claim 3 wherein said catalyst element is at least one element selected from nickel, iron, cobalt, palladium and platinum.
Claim 7
Dependent Claim
121 words
A thin film transistor comprising: a gate electrode provided on an insulating surface; a gate insulating film provided on said gate electrode; and a source region, a drain region and a channel-forming region which comprise crystalline silicon and are provided on said gate insulating film, said channel-forming region being provided between said source region and said drain region, wherein said source region and said drain region contain a catalyst element, and density of said catalyst element within said source region and said drain region exceeds 1×10 17 atoms/cm 3 , and wherein said channel-forming region contains the same element as said catalyst element, and density of said catalyst element in said channel-forming region is less than 1×10 17 atoms/cm 3 .
Claim 8
Dependent Claim
121 words
A thin film transistor comprising: a gate electrode provided on an insulating surface; a gate insulating film provided on said gate electrode; and a source region, a drain region and a channel-forming region which comprise crystalline silicon and are provided on said gate insulating film, said channel-forming region being provided between said source region and said drain region, wherein said source region and said drain region contain a catalyst element, and density of said catalyst element within said source region and said drain region exceeds 1×10 17 atoms/cm 3 , and wherein said channel-forming region contains the same element as said catalyst element, and density of said catalyst element in said channel-forming region is less than 1×10 17 atoms/cm 3 .
Claim 9
Dependent Claim
22 words
The transistor of claim 5 wherein said catalyst element is at least one element selected from nickel, iron, cobalt, palladium and platinum.
Claim 10
Dependent Claim
131 words
A thin film transistor comprising: a source region, a drain region and a channel-forming region which comprise crystalline silicon and are provided on an insulating surface, said channel-forming region being provided between said source region and said drain region; a gate insulating film provided on said channel-forming region; and a gate electrode provided on said gate insulating film, wherein said source region and said drain region contain a catalyst element, and density of said catalyst element within said source region and said drain region exceeds 1×10 17 atoms/cm 3 , wherein said channel-forming region contains the same element as said catalyst element, and density of said catalyst element in said channel-forming region is less than 1×10 17 atoms/cm 3 , and wherein said source region and said drain region contain phosphorus.
Claim 11
Dependent Claim
131 words
A thin film transistor comprising: a source region, a drain region and a channel-forming region which comprise crystalline silicon and are provided on an insulating surface, said channel-forming region being provided between said source region and said drain region; a gate insulating film provided on said channel-forming region; and a gate electrode provided on said gate insulating film, wherein said source region and said drain region contain a catalyst element, and density of said catalyst element within said source region and said drain region exceeds 1×10 17 atoms/cm 3 , wherein said channel-forming region contains the same element as said catalyst element, and density of said catalyst element in said channel-forming region is less than 1×10 17 atoms/cm 3 , and wherein said source region and said drain region contain phosphorus.
Claim 12
Dependent Claim
22 words
The transistor of claim 7 wherein said catalyst element is at least one element selected from nickel, iron, cobalt, palladium and platinum.
Claim 13
Dependent Claim
131 words
A thin film transistor comprising: a gate electrode provided on an insulating surface; a gate insulating film provided on said gate electrode; and a source region, a drain region and a channel-forming region which comprise crystalline silicon and are provided on said gate insulating film, said channel-forming region being provided between said source region and said drain region, wherein said source region and said drain region contain a catalyst element, and density of said catalyst element within said source region and said drain region exceeds 1×10 17 atoms/cm 3 , wherein said channel-forming region contains the same element as said catalyst element, and density of said catalyst element in said channel-forming region is less than 1×10 17 atoms/cm 3 , and wherein said source region and said drain region contain phosphorus.
Claim 14
Dependent Claim
131 words
A thin film transistor comprising: a gate electrode provided on an insulating surface; a gate insulating film provided on said gate electrode; and a source region, a drain region and a channel-forming region which comprise crystalline silicon and are provided on said gate insulating film, said channel-forming region being provided between said source region and said drain region, wherein said source region and said drain region contain a catalyst element, and density of said catalyst element within said source region and said drain region exceeds 1×10 17 atoms/cm 3 , wherein said channel-forming region contains the same element as said catalyst element, and density of said catalyst element in said channel-forming region is less than 1×10 17 atoms/cm 3 , and wherein said source region and said drain region contain phosphorus.
Claim 15
Dependent Claim
22 words
The transistor of claim 9 wherein said catalyst element is at least one element selected from nickel, iron, cobalt, palladium and platinum.
Claim 16
Dependent Claim
137 words
A thin film transistor comprising: a source region, a drain region and a channel-forming region which comprise crystalline silicon and are provided on an insulating surface, said channel-forming region being provided between said source region and said drain region; a gate insulating film provided on said channel-forming region; and a gate electrode provided on said gate insulating film, wherein said source region and said drain region contain a catalyst element, and density of said catalyst element within said source region and said drain region exceeds 1×10 17 atoms/cm 3 , wherein said channel-forming region contains the same element as said catalyst element, and density of said catalyst element in said channel-forming region is less than 1×10 17 atoms/cm 3 , and wherein said source region and said drain region have a sheet resistance less than 10 kΩ/□.
Claim 17
Dependent Claim
137 words
A thin film transistor comprising: a source region, a drain region and a channel-forming region which comprise crystalline silicon and are provided on an insulating surface, said channel-forming region being provided between said source region and said drain region; a gate insulating film provided on said channel-forming region; and a gate electrode provided on said gate insulating film, wherein said source region and said drain region contain a catalyst element, and density of said catalyst element within said source region and said drain region exceeds 1×10 17 atoms/cm 3 , wherein said channel-forming region contains the same element as said catalyst element, and density of said catalyst element in said channel-forming region is less than 1×10 17 atoms/cm 3 , and wherein said source region and said drain region have a sheet resistance less than 10 kΩ/□.
Claim 18
Dependent Claim
22 words
The transistor of claim 11 wherein said catalyst element is at least one element selected from nickel, iron, cobalt, palladium and platinum.
Claim 19
Dependent Claim
138 words
A thin film transistor comprising: a gate electrode provided on an insulating surface; a gate insulating film provided on said gate electrode; and a source region, a drain region and a channel-forming region which comprise crystalline silicon and are provided on said gate insulating film, said channel-forming region being provided between said source region and said drain region, wherein said source region and said drain region contain a catalyst element, and density of said catalyst element within said source region and said drain region exceeds 1×10 17 atoms/cm 3 , and wherein said channel-forming region contains the same element as said catalyst element, and density of said catalyst element in said channel-forming region is less than 1×10 17 atoms/cm 3 , and wherein said source region and said drain region have a sheet resistance less than 10 kΩ/□.
Claim 20
Dependent Claim
138 words
A thin film transistor comprising: a gate electrode provided on an insulating surface; a gate insulating film provided on said gate electrode; and a source region, a drain region and a channel-forming region which comprise crystalline silicon and are provided on said gate insulating film, said channel-forming region being provided between said source region and said drain region, wherein said source region and said drain region contain a catalyst element, and density of said catalyst element within said source region and said drain region exceeds 1×10 17 atoms/cm 3 , and wherein said channel-forming region contains the same element as said catalyst element, and density of said catalyst element in said channel-forming region is less than 1×10 17 atoms/cm 3 , and wherein said source region and said drain region have a sheet resistance less than 10 kΩ/□.
Claim 21
Dependent Claim
22 words
The transistor of claim 13 wherein said catalyst element is at least one element selected from nickel, iron, cobalt, palladium and platinum.
Claim 22
Dependent Claim
142 words
A thin film transistor comprising: a pair of high density impurity regions and a channel-forming region which comprise crystalline silicon and are provided on an insulating surface, said channel-forming region being provided between said pair of high density impurity regions; at least one low density impurity region provided between said channel-forming region and one of said high density impurity regions; a gate insulating film provided on said channel-forming region; and a gate electrode provided on said gate insulating film, wherein said pair of high density impurity regions contain a catalyst element, and density of said catalyst element within said pair of high density impurity regions exceeds 1×10 17 atoms/cm 3 , and wherein said channel-forming region contains the same element as said catalyst element, and density of said catalyst element in said channel-forming region is less than 1×10 17 atoms/cm 3 .
Claim 23
Dependent Claim
142 words
A thin film transistor comprising: a pair of high density impurity regions and a channel-forming region which comprise crystalline silicon and are provided on an insulating surface, said channel-forming region being provided between said pair of high density impurity regions; at least one low density impurity region provided between said channel-forming region and one of said high density impurity regions; a gate insulating film provided on said channel-forming region; and a gate electrode provided on said gate insulating film, wherein said pair of high density impurity regions contain a catalyst element, and density of said catalyst element within said pair of high density impurity regions exceeds 1×10 17 atoms/cm 3 , and wherein said channel-forming region contains the same element as said catalyst element, and density of said catalyst element in said channel-forming region is less than 1×10 17 atoms/cm 3 .
Claim 24
Dependent Claim
22 words
The transistor of claim 15 wherein said catalyst element is at least one element selected from nickel, iron, cobalt, palladium and platinum.
Claim 25
Dependent Claim
21 words
The transistor of claim 15 wherein said pair of high density impurity regions are a source region and a drain region.
Claim 26
Dependent Claim
143 words
A thin film transistor comprising: a gate electrode provided on an insulating surface; a gate insulating film provided on said gate electrode; and a pair of high density impurity regions and a channel-forming region which comprise crystalline silicon and are provided on said gate insulating film, said channel-forming region being provided between said pair of high density impurity regions; and at least one low density impurity region provided between said channel-forming region and one of said high density impurity regions, wherein said pair of high density impurity regions contain a catalyst element, and density of said catalyst element within said pair of high density impurity regions exceeds 1×10 17 atoms/cm 3 , and wherein said channel-forming region contains the same element as said catalyst element, and density of said catalyst element in said channel-forming region is less than 1×10 17 atoms/cm 3 .
Claim 27
Dependent Claim
143 words
A thin film transistor comprising: a gate electrode provided on an insulating surface; a gate insulating film provided on said gate electrode; and a pair of high density impurity regions and a channel-forming region which comprise crystalline silicon and are provided on said gate insulating film, said channel-forming region being provided between said pair of high density impurity regions; and at least one low density impurity region provided between said channel-forming region and one of said high density impurity regions, wherein said pair of high density impurity regions contain a catalyst element, and density of said catalyst element within said pair of high density impurity regions exceeds 1×10 17 atoms/cm 3 , and wherein said channel-forming region contains the same element as said catalyst element, and density of said catalyst element in said channel-forming region is less than 1×10 17 atoms/cm 3 .
Claim 28
Dependent Claim
22 words
The transistor of claim 18 wherein said catalyst element is at least one element selected from nickel, iron, cobalt, palladium and platinum.
Claim 29
Dependent Claim
21 words
The transistor of claim 18 wherein said pair of high density impurity regions are a source region and a drain region.
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