US5313076A
Expired / Lapsed
US
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Thin film transistor and semiconductor device including a laser crystallized semiconductor
Assignee: Semiconductor Energy Laboratory Co Ltd
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Filing: 1992-03-17
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Granted: 1994-05-17
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Expires: 2012-03-17
Abstract
Abstract A semiconductor material and a method for forming the same, the semiconductor material having fabricated by a process comprising irradiating a laser beam or a high intensity light equivalent to a laser beam to an amorphous silicon film containing therein carbon, nitrogen, and oxygen each at a concentration of 5×10 19 atoms·cm -3 or lower, preferably 1×10 19 atoms·cm -3 or lower, without melting the amorphous silicon film. The present invention provides thin film semiconductors having high mobility at an excellent reproducibility, the semiconductor materials being useful for fabricating compact thin film semiconductor devices such as thin film transistors improved in device characteristics.
Inventors
- 👤 Shunpei Yamazaki
- 👤 Hongyong Zhang
- 👤 Naoto Kusumoto
- 👤 Yasuhiko Takemura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 01:12
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/031; H10D30/0312; H10D30/0314; H10D30/60; H10D30/67; H10D30/6729; H10D30/673; H10D30/6731; H10D30/674; H10D30/6741; H10D30/6743; H10D30/6745; H10D62/00; H10D62/80; H10D62/83; H10P; H10P14/00; H10P14/60; H10P14/65; H10P14/6516; H10P14/6536; H10P14/6542
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
104 words
A thin film transistor comprising an activation layer produced by a process comprising the steps of: forming on a surface an intrinsic or substantially intrinsic silicon semiconductor film containing therein carbon, nitrogen and oxygen at a concentration of 5×10 19 atoms·cm -3 or less respectively; irradiating said entire semiconductor film with a laser beam or a light having a strength equivalent to the laser beam without melting the semiconductor film to make the degree of crystallinity of the entire semiconductor film higher; forming an insulated gate electrode on said semiconductor film; and forming a source region and a drain region in said semiconductor film.
Claim 2
Dependent Claim
104 words
A thin film transistor comprising an activation layer produced by a process comprising the steps of: forming on a surface an intrinsic or substantially intrinsic silicon semiconductor film containing therein carbon, nitrogen and oxygen at a concentration of 5×10 19 atoms·cm -3 or less respectively; irradiating said entire semiconductor film with a laser beam or a light having a strength equivalent to the laser beam without melting the semiconductor film to make the degree of crystallinity of the entire semiconductor film higher; forming an insulated gate electrode on said semiconductor film; and forming a source region and a drain region in said semiconductor film.
Claim 3
Dependent Claim
45 words
The thin film transistor of claim 1 wherein said activation layer comprises the semiconductor film having the higher degree of crystallinity and said semiconductor film having the higher degree of crystallinity has a Raman peak of 517 cm -1 or less in Raman spectroscopy thereof.
Claim 4
Dependent Claim
20 words
The thin film transistor of claim 1 wherein said activation layer includes a channel of said thin film transistor therein.
Claim 5
Dependent Claim
15 words
The transistor of claim 1 wherein said concentration is confirmed by secondary ion mass spectrography.
Claim 6
Dependent Claim
110 words
A thin film transistor comprising a semiconductor channel area produced by a process comprising the steps of: forming on a surface an intrinsic or substantially intrinsic non-single crystalline semiconductor film containing therein carbon, nitrogen and oxygen at a concentration of 5×10 19 atoms·cm -3 or less respectively; irradiating said intrinsic or substantially intrinsic non-single crystalline semiconductor film with a laser beam or a light having a strength equivalent to the laser beam without melting the semiconductor film to make the degree of crystallinity of the semiconductor film higher; forming an insulated gate electrode on said semiconductor film; and forming a source region and a drain region in said semiconductor film.
Claim 7
Dependent Claim
110 words
A thin film transistor comprising a semiconductor channel area produced by a process comprising the steps of: forming on a surface an intrinsic or substantially intrinsic non-single crystalline semiconductor film containing therein carbon, nitrogen and oxygen at a concentration of 5×10 19 atoms·cm -3 or less respectively; irradiating said intrinsic or substantially intrinsic non-single crystalline semiconductor film with a laser beam or a light having a strength equivalent to the laser beam without melting the semiconductor film to make the degree of crystallinity of the semiconductor film higher; forming an insulated gate electrode on said semiconductor film; and forming a source region and a drain region in said semiconductor film.
Claim 8
Dependent Claim
30 words
The thin film transistor of claim 5 wherein the semiconductor film having undergone said irradiating step has a Raman peak of 517 cm -1 or less in Raman spectroscopy thereof.
Claim 9
Dependent Claim
15 words
The thin film transistor of claim 5 wherein said light comprises an excimer laser pulse.
Claim 10
Dependent Claim
15 words
The transistor of claim 5 wherein said concentration is confirmed by secondary ion mass spectrography.
Claim 11
Dependent Claim
125 words
A thin film transistor comprising a channel-forming area produced by a process comprising the steps of: covering a surface of an intrinsic or substantially intrinsic non-single crystalline semiconductor film containing therein oxygen, nitrogen and carbon at a concentration of 5×10 19 atom·cm -3 or less respectively with a protection film made from a material capable of transmitting a laser beam or a light having a strength equivalent to the laser beam; irradiating said entire semiconductor film with said laser beam or said light through said protective film without melting said semiconductor film to make the degree of crystallinity of said semiconductor film higher; forming an insulated gate electrode on said semiconductor film; and forming a source region and a drain region in said semiconductor film.
Claim 12
Dependent Claim
125 words
A thin film transistor comprising a channel-forming area produced by a process comprising the steps of: covering a surface of an intrinsic or substantially intrinsic non-single crystalline semiconductor film containing therein oxygen, nitrogen and carbon at a concentration of 5×10 19 atom·cm -3 or less respectively with a protection film made from a material capable of transmitting a laser beam or a light having a strength equivalent to the laser beam; irradiating said entire semiconductor film with said laser beam or said light through said protective film without melting said semiconductor film to make the degree of crystallinity of said semiconductor film higher; forming an insulated gate electrode on said semiconductor film; and forming a source region and a drain region in said semiconductor film.
Claim 13
Dependent Claim
30 words
The transistor of claim 9 wherein said process further comprises the step of laser annealing said intrinsic or substantially intrinsic non-single crystalline semiconductor film under vacuum after said covering step.
Claim 14
Dependent Claim
28 words
The transistor of claim 9 wherein said protective film comprises a material selected from the group consisting of silicon oxide, silicon nitride, silicon carbide and a mixture thereof.
Claim 15
Dependent Claim
21 words
The transistor of claim 9 wherein thickness of said protective film is in the range of from 5 to 1000 nm.
Claim 16
Dependent Claim
15 words
The transistor of claim 9 wherein said concentration is confirmed by secondary ion mass spectrography.
Claim 17
Dependent Claim
20 words
The transistor of claims 1, 5 or 9 wherein said intrinsic or substantially intrinsic semiconductor film has an amorphous structure.
Claim 18
Dependent Claim
83 words
A thin film transistor comprising: an intrinsic or substantially intrinsic semiconductor film included in a channel of said thin film transistor, said intrinsic or substantially intrinsic semiconductor film containing therein carbon, nitrogen and oxygen at a concentration of 5×10 19 atoms·cm -3 or less respectively and having a Raman peak of 517 cm -1 or less in Raman spectroscopy thereof; an insulated gate electrode formed on said semiconductor film; and a source region and a drain region formed adjacent to said semiconductor film.
Claim 19
Dependent Claim
83 words
A thin film transistor comprising: an intrinsic or substantially intrinsic semiconductor film included in a channel of said thin film transistor, said intrinsic or substantially intrinsic semiconductor film containing therein carbon, nitrogen and oxygen at a concentration of 5×10 19 atoms·cm -3 or less respectively and having a Raman peak of 517 cm -1 or less in Raman spectroscopy thereof; an insulated gate electrode formed on said semiconductor film; and a source region and a drain region formed adjacent to said semiconductor film.
Claim 20
Dependent Claim
15 words
The transistor of claim 15 wherein said concentration is confirmed by secondary ion mass spectrography.
References Cited (Backward Citations)
US5091334A
Cited
US4727044A
Cited
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