US5773846A
Expired / Lapsed
US
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Transistor and process for fabricating the same
Assignee: Semiconductor Energy Laboratory Co Ltd
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Filing: 1995-05-24
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Granted: 1998-06-30
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Expires: 2015-05-24
Abstract
Abstract A thin film transistor, which comprises crystallizing an amorphous silicon film, forming thereon a gate insulating film and a gate electrode, implanting impurities in a self-aligned manner, adhering a coating containing a catalyst element which accelerates the crystallization of the silicon film, and annealing the resulting structure at a temperature lower than the deformation temperature of the substrate to activate the doped impurities. Otherwise, the catalyst element can be incorporated into the structure by introducing it into the impurity region by means of ion implantation and the like. Also, a thin film transistor, which comprises forming a gate electrode, a gate insulating film, and an amorphous silicon film on a substrate, implanting impurities into the amorphous silicon film to form source and drain regions as the impurity regions, introducing a catalyst element into the impurity region by adhering a coating containing the catalyst element of by means of ion doping and the like, and annealing the resulting structure at a temperature lower than the deformation temperature of the substrate to activate the doped impurities.
Inventors
- 👤 Hongyong Zhang
- 👤 Toru Takayama
- 👤 Yasuhiko Takemura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 02:30
CPC Classifications
H; H10; H10P; H10P30/00; H10P30/20; H10P30/202; H10P30/204; H10D; H10D30/00; H10D30/60; H10D30/67; H10D30/01; H10D30/021; H10D30/031; H10D30/0312; H10D30/0314; H10D30/0316; H10D30/0321; H10D30/6704; H10D30/6713; H10D30/6729; H10D30/673; H10D30/6731; H10D30/6732; H10D30/6737; H10D30/6739; H10D30/674; H10D30/6741; H10D30/6743; H10D30/6745; H10P14/00; H10P14/20; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P14/38; H10P14/3802; H10P14/3806; H10P30/208
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
88 words
A thin film transistor comprising: a channel semiconductor region comprising intrinsic silicon formed on an insulating surface; and source and drain semiconductor regions comprising one conductivity type silicon doped with one conductivity type impurity, wherein said channel semiconductor region extends between said source and drain semiconductor regions; wherein said source and drain semiconductor regions contain a catalyst element for promoting a crystallization of silicon, and wherein a concentration of said catalyst element in said channel semiconductor region is lower than that in said source and drain semiconductor regions.
Claim 2
Dependent Claim
88 words
A thin film transistor comprising: a channel semiconductor region comprising intrinsic silicon formed on an insulating surface; and source and drain semiconductor regions comprising one conductivity type silicon doped with one conductivity type impurity, wherein said channel semiconductor region extends between said source and drain semiconductor regions; wherein said source and drain semiconductor regions contain a catalyst element for promoting a crystallization of silicon, and wherein a concentration of said catalyst element in said channel semiconductor region is lower than that in said source and drain semiconductor regions.
Claim 3
Dependent Claim
21 words
The transistor of claim 1 wherein said catalyst element is selected from the group consisting of nickel, iron, cobalt and platinum.
Claim 4
Dependent Claim
27 words
The transistor of claim 1 wherein said source and drain regions contain said catalyst element at a concentration of not higher than 1×10 20 atoms/cm 3 .
Claim 5
Dependent Claim
24 words
The transistor of claim 1 wherein the concentration of said catalyst element in said channel region is lower than 1×10 17 atoms/cm 3 .
Claim 6
Dependent Claim
98 words
A thin film transistor comprising: a semiconductor film comprising silicon formed on an insulating surface; a channel region formed within said semiconductor film and having an intrinsic conductivity; and source and drain regions formed within said semiconductor film with said channel region interposed between said source and drain regions, each of said source and drain regions having one conductivity type, wherein said source and drain regions contain a catalyst element for promoting a crystallization of silicon, and wherein a concentration of said catalyst element in said channel region is lower than that in said source and drain regions.
Claim 7
Dependent Claim
98 words
A thin film transistor comprising: a semiconductor film comprising silicon formed on an insulating surface; a channel region formed within said semiconductor film and having an intrinsic conductivity; and source and drain regions formed within said semiconductor film with said channel region interposed between said source and drain regions, each of said source and drain regions having one conductivity type, wherein said source and drain regions contain a catalyst element for promoting a crystallization of silicon, and wherein a concentration of said catalyst element in said channel region is lower than that in said source and drain regions.
Claim 8
Dependent Claim
21 words
The transistor of claim 5 wherein said catalyst element is selected from the group consisting of nickel, iron, cobalt and platinum.
Claim 9
Dependent Claim
27 words
The transistor of claim 5 wherein said source and drain regions contain said catalyst element at a concentration of not higher than 1×10 20 atoms/cm 3 .
Claim 10
Dependent Claim
12 words
The transistor of claim 5 wherein said semiconductor film comprises crystalline silicon.
Claim 11
Dependent Claim
24 words
The transistor of claim 5 wherein the concentration of said catalyst element in said channel region is lower than 1×10 17 atoms/cm 3 .
Claim 12
Dependent Claim
101 words
A thin film transistor comprising: a semiconductor film comprising silicon formed on an insulating surface; a channel region formed within said semiconductor film and having an intrinsic conductivity; and source and drain regions formed within said semiconductor film with said channel region interposed between said source and drain regions, each of said source and drain regions is added with one conductivity type dopant, wherein said source and drain regions contain a catalyst element for promoting a crystallization of silicon, and wherein a concentration of said catalyst element in said channel region is lower than that in said source and drain regions.
Claim 13
Dependent Claim
101 words
A thin film transistor comprising: a semiconductor film comprising silicon formed on an insulating surface; a channel region formed within said semiconductor film and having an intrinsic conductivity; and source and drain regions formed within said semiconductor film with said channel region interposed between said source and drain regions, each of said source and drain regions is added with one conductivity type dopant, wherein said source and drain regions contain a catalyst element for promoting a crystallization of silicon, and wherein a concentration of said catalyst element in said channel region is lower than that in said source and drain regions.
Claim 14
Dependent Claim
21 words
The transistor of claim 10 wherein said catalyst element is selected from the group consisting of nickel, iron, cobalt and platinum.
Claim 15
Dependent Claim
27 words
The transistor of claim 10 wherein said source and drain regions contain said catalyst element at a concentration of not higher than 1×10 20 atoms/cm 3 .
Claim 16
Dependent Claim
24 words
The transistor of claim 10 wherein the concentration of said catalyst element in said channel region is lower than 1×10 17 atoms/cm 3 .
Claim 17
Dependent Claim
10 words
The transistor of claim 10 wherein said dopant is boron.
Claim 18
Dependent Claim
10 words
The transistor of claim 10 wherein said dopant is phosphorus.
Claim 19
Dependent Claim
104 words
A thin film transistor comprising: a semiconductor film comprising silicon formed on an insulating surface; a channel region formed within said semiconductor film and having an intrinsic conductivity; and source and drain regions formed within said semiconductor film with said channel region interposed between said source and drain regions, each of said source and drain regions doped with one conductivity type impurity, wherein said source and drain regions contain a catalyst element for promoting an activation of said impurity within said regions, and wherein a concentration of said catalyst element in said channel region is lower than that in said source and drain regions.
Claim 20
Dependent Claim
104 words
A thin film transistor comprising: a semiconductor film comprising silicon formed on an insulating surface; a channel region formed within said semiconductor film and having an intrinsic conductivity; and source and drain regions formed within said semiconductor film with said channel region interposed between said source and drain regions, each of said source and drain regions doped with one conductivity type impurity, wherein said source and drain regions contain a catalyst element for promoting an activation of said impurity within said regions, and wherein a concentration of said catalyst element in said channel region is lower than that in said source and drain regions.
Claim 21
Dependent Claim
21 words
The transistor of claim 16 wherein said catalyst element is selected from the group consisting of nickel, iron, cobalt and platinum.
Claim 22
Dependent Claim
27 words
The transistor of claim 16 wherein said source and drain regions contain said catalyst element at a concentration of not higher than 1×10 20 atoms/cm 3 .
Claim 23
Dependent Claim
24 words
The transistor of claim 16 wherein the concentration of said catalyst element in said channel region is lower than 1×10 17 atoms/cm 3 .
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