US5656825A
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Thin film transistor having crystalline semiconductor layer obtained by irradiation
Assignee: Semiconductor Energy Laboratory Co Ltd
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Filing: 1995-06-07
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Granted: 1997-08-12
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Expires: 2015-06-07
Abstract
Abstract An amorphous semiconductor film having a thickness of 400Å or more is formed on an insulating surface and is wholly or selectively etched to form a region having a thickness 300Å or less. This is used as a channel-forming region in a TFT.
Inventors
- 👤 Naoto Kusumoto
- 👤 Yasuhiko Takemura
- 👤 Hisashi Ohtani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:57
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/031; H10D30/0321; C; C30; C30B; C30B1/00; C30B1/02; C30B1/023; C30B29/00; C30B29/02; C30B29/06; H10D30/0312; H10D30/0314; H10D30/60; H10D30/67; H10D30/6757; H10D86/00; H10D86/40; H10D86/421; H10D86/427; H10D86/60; H10D30/6704; H10D30/6713; H10D30/6715; H10D30/6729; H10D30/673; H10D30/6731; H10D30/674; H10D30/6741; H10D30/6743; H10D30/6745
Claims Analysis
Total Claims: 61
Claim 1
Independent Claim
81 words
A thin film transistor having a maximum value of electric field effect mobility of 50 cm 2 /Vs or more and comprising an active layer of thin fill semiconductor which is present on an insulating surface, and a marker for aligning a mask comprising the same semiconductor with said active layer and provided separately from said active layer and on said insulating surface, wherein said semiconductor is thinner in at least a part of said active layer than in said marker.
Claim 2
Dependent Claim
81 words
A thin film transistor having a maximum value of electric field effect mobility of 50 cm 2 /Vs or more and comprising an active layer of thin fill semiconductor which is present on an insulating surface, and a marker for aligning a mask comprising the same semiconductor with said active layer and provided separately from said active layer and on said insulating surface, wherein said semiconductor is thinner in at least a part of said active layer than in said marker.
Claim 3
Dependent Claim
26 words
The transistor of claim 1 wherein a part of said active layer having a gate electrode formed thereon has an average thickness of 300Å or less.
Claim 4
Dependent Claim
12 words
The transistor of claim 1 wherein said semiconductor comprises an amorphous semiconductor.
Claim 5
Dependent Claim
15 words
The transistor of claim 1 wherein said semiconductor comprises a semiconductor crystallized by thermal annealing.
Claim 6
Dependent Claim
29 words
The transistor of claim 4 wherein the crystallization is promoted during said thermal annealing by using an element of at least one of nickel, palladium, platinum, cobalt and iron.
Claim 7
Dependent Claim
11 words
The transistor of claim 1 wherein said part comprises a channel.
Claim 8
Dependent Claim
15 words
The transistor of claim 6 wherein said channel has a thickness of 300Å or less.
Claim 9
Dependent Claim
10 words
The transistor of claim 1 wherein said semiconductor is crystalline.
Claim 10
Dependent Claim
85 words
A thin film semiconductor integrated circuit comprising: at least two thin film transistors formed on an insulating surface, said at least two thin film transistors being formed from a semiconductor film formed on an insulating surface; and a marker for aligning a mask, comprising the same material as said semiconductor film and provided separately from said semiconductor film and on said insulating surface, wherein at least a part of said semiconductor film of said at least two thin film transistors is thinner than said marker.
Claim 11
Dependent Claim
85 words
A thin film semiconductor integrated circuit comprising: at least two thin film transistors formed on an insulating surface, said at least two thin film transistors being formed from a semiconductor film formed on an insulating surface; and a marker for aligning a mask, comprising the same material as said semiconductor film and provided separately from said semiconductor film and on said insulating surface, wherein at least a part of said semiconductor film of said at least two thin film transistors is thinner than said marker.
Claim 12
Dependent Claim
65 words
The circuit of claim 9 wherein of an active layer of crystalline semiconductor in a first thin film transistor a part having a gate electrode formed thereon has an average thickness of 300Å or less, and of an active layer of crystalline semiconductor in a second thin film transistor a part having a gate electrode formed thereon has an average thickness of 400Å or more.
Claim 13
Dependent Claim
11 words
The circuit of claim 2 wherein said part comprises a channel.
Claim 14
Dependent Claim
15 words
The circuit of claim 11 wherein said channel has a thickness of 300Å or less.
Claim 15
Dependent Claim
13 words
The circuit of claim 9 wherein said semiconductor film is a crystalline film.
Claim 16
Dependent Claim
60 words
A thin film transistor comprising: a thin film semiconductor layer formed on an insulating surface; gate electrodes formed thereon, and a marker for aligning a mask, comprising the same material as said semiconductor layer and provided separately from said semiconductor layer and on said insulating surface, wherein at least a part of said semiconductor layer is thinner than said marker.
Claim 17
Dependent Claim
60 words
A thin film transistor comprising: a thin film semiconductor layer formed on an insulating surface; gate electrodes formed thereon, and a marker for aligning a mask, comprising the same material as said semiconductor layer and provided separately from said semiconductor layer and on said insulating surface, wherein at least a part of said semiconductor layer is thinner than said marker.
Claim 18
Dependent Claim
48 words
The transistor of claim 14 wherein of the semiconductor layer, a part having the gate electrode formed thereon has an average thickness of 300Å or less, and a part having a contact of a source or a drain formed thereon has an average thickness of 400Å or more.
Claim 19
Dependent Claim
13 words
The transistor of claim 14 wherein said semiconductor layer comprises an amorphous semiconductor.
Claim 20
Dependent Claim
16 words
The transistor of claim 14 wherein said semiconductor layer comprises a semiconductor crystallized by thermal annealing.
Claim 21
Dependent Claim
29 words
The transistor of claim 17 wherein the crystallization is promoted during said thermal annealing by using an element of at least one of nickel, palladium, platinum, cobalt and iron.
Claim 22
Dependent Claim
11 words
The transistor of claim 14 wherein said part comprises a channel.
Claim 23
Dependent Claim
15 words
The transistor of claim 19 wherein said channel has a thickness of 300Å or less.
Claim 24
Dependent Claim
13 words
The transistor of claim 14 wherein said semiconductor layer is a crystalline layer.
Claim 25
Dependent Claim
76 words
A thin film semiconductor device comprising: an active layer of thin film semiconductor which is present on an insulating surface; a gate insulating film having a thickness of 500Å or less, and a marker for aligning a mask, comprising the same semiconductor with said active layer and provided separately from said active layer and on said insulating surface, wherein said semiconductor is thinner in at least a part of said active layer than in said marker.
Claim 26
Dependent Claim
76 words
A thin film semiconductor device comprising: an active layer of thin film semiconductor which is present on an insulating surface; a gate insulating film having a thickness of 500Å or less, and a marker for aligning a mask, comprising the same semiconductor with said active layer and provided separately from said active layer and on said insulating surface, wherein said semiconductor is thinner in at least a part of said active layer than in said marker.
Claim 27
Dependent Claim
26 words
The device of claim 22 wherein a part of said active layer having a gate electrode formed thereon has an average thickness of 300Å or less.
Claim 28
Dependent Claim
12 words
The device of claim 22 whereto said semiconductor comprises an amorphous semiconductor.
Claim 29
Dependent Claim
15 words
The device of claim 22 whereto said semiconductor comprises a semiconductor crystallized by thermal annealing.
Claim 30
Dependent Claim
29 words
The device of claim 25 wherein the crystallization is promoted during said thermal annealing by using an element of at least one of nickel, palladium, platinum, cobalt and iron.
Claim 31
Dependent Claim
11 words
The device of claim 22 wherein said part comprises a channel.
Claim 32
Dependent Claim
15 words
The device of claim 27 wherein said channel has a thickness of 300Å or less.
Claim 33
Dependent Claim
10 words
The device of claim 22 wherein said semiconductor is crystalline.
Claim 34
Dependent Claim
93 words
A thin film semiconductor device comprising: a thin film semiconductor layer formed on an insulating surface, and a marker for aligning a mask, comprising the same material as said semiconductor layer and provided separately from said semiconductor layer and on said insulating surface, wherein at least a part of said semiconductor layer is thinner than said marker, and wherein the average thickness of a region of the semiconductor layer having a gate electrode formed thereon is substantially the same as the average thickness of a part of the periphery of said semiconductor layer.
Claim 35
Dependent Claim
93 words
A thin film semiconductor device comprising: a thin film semiconductor layer formed on an insulating surface, and a marker for aligning a mask, comprising the same material as said semiconductor layer and provided separately from said semiconductor layer and on said insulating surface, wherein at least a part of said semiconductor layer is thinner than said marker, and wherein the average thickness of a region of the semiconductor layer having a gate electrode formed thereon is substantially the same as the average thickness of a part of the periphery of said semiconductor layer.
Claim 36
Dependent Claim
13 words
The device of claim 30 wherein said semiconductor layer comprises an amorphous semiconductor.
Claim 37
Dependent Claim
16 words
The device of claim 30 whereto said semiconductor layer comprises a semiconductor crystallized by thermal annealing.
Claim 38
Dependent Claim
29 words
The device of claim 32 wherein the crystallization is promoted during said thermal annealing by using an element of at least one of nickel, palladium, platinum, cobalt and iron.
Claim 39
Dependent Claim
13 words
The device of claim 30 wherein said semiconductor layer is a crystalline layer.
Claim 40
Dependent Claim
100 words
A thin film semiconductor device comprising: an active layer of thin film semiconductor which is present on an insulating surface and has a thickness of 300Å or less; a gate insulating film which has a thickness of 200Å to 1500Å and is formed by non-thermal oxidation, and a marker for aligning a mask, comprising the same semiconductor with said active layer and provided separately from said active layer and on said insulating surface, said marker having a thickness of 400Å to 1500Å, wherein said semiconductor is thinner in at least a part of said active layer than in said marker.
Claim 41
Dependent Claim
100 words
A thin film semiconductor device comprising: an active layer of thin film semiconductor which is present on an insulating surface and has a thickness of 300Å or less; a gate insulating film which has a thickness of 200Å to 1500Å and is formed by non-thermal oxidation, and a marker for aligning a mask, comprising the same semiconductor with said active layer and provided separately from said active layer and on said insulating surface, said marker having a thickness of 400Å to 1500Å, wherein said semiconductor is thinner in at least a part of said active layer than in said marker.
Claim 42
Dependent Claim
26 words
The device of claim 35 wherein a part of said active layer having a gate electrode formed thereon has an average thickness of 300Å or less.
Claim 43
Dependent Claim
12 words
The device of claim 35 wherein said semiconductor comprises an amorphous semiconductor.
Claim 44
Dependent Claim
15 words
The device of claim 35 wherein said semiconductor comprises a semiconductor crystallized by thermal annealing.
Claim 45
Dependent Claim
29 words
The device of claim 38 wherein the crystallization is promoted during said thermal annealing by using an element of at least one of nickel, palladium, platinum, cobalt and iron.
Claim 46
Dependent Claim
11 words
The device of claim 35 wherein said part comprises a channel.
Claim 47
Dependent Claim
10 words
The device of claim 35 wherein said semiconductor is crystalline.
Claim 48
Dependent Claim
89 words
A thin film semiconductor device comprising: a thin film semiconductor layer which is present on an insulating surface and comprises a channel; a gate insulating film and a gate electrode on the semiconductor layer, and a marker for aligning a mask, comprising the same material as said semiconductor layer and provided separately from said semiconductor layer and on said insulating surface, wherein a part of said thin film semiconductor layer is thinner than said marker, said part of said semiconductor layer containing said channel and extending beyond said channel.
Claim 49
Dependent Claim
89 words
A thin film semiconductor device comprising: a thin film semiconductor layer which is present on an insulating surface and comprises a channel; a gate insulating film and a gate electrode on the semiconductor layer, and a marker for aligning a mask, comprising the same material as said semiconductor layer and provided separately from said semiconductor layer and on said insulating surface, wherein a part of said thin film semiconductor layer is thinner than said marker, said part of said semiconductor layer containing said channel and extending beyond said channel.
Claim 50
Dependent Claim
19 words
The device of claim 42 wherein said part of said semiconductor layer has a thickness of 300Å or less.
Claim 51
Dependent Claim
13 words
The device of claim 42 wherein said semiconductor layer comprises an amorphous semiconductor.
Claim 52
Dependent Claim
16 words
The device of claim 42 wherein said semiconductor layer comprises a semiconductor crystallized by thermal annealing.
Claim 53
Dependent Claim
29 words
The device of claim 45 wherein the crystallization is promoted during said thermal annealing by using an element of at least one of nickel, palladium, platinum, cobalt and iron.
Claim 54
Dependent Claim
13 words
The device of claim 42 wherein said semiconductor layer is a crystalline layer.
Claim 55
Dependent Claim
27 words
The device of claim 42 wherein said channel has a thickness of 300Å or less, and said gate insulating film has a thickness of 200Å to 1500Å.
Claim 56
Dependent Claim
67 words
A thin film semiconductor integrated circuit comprising a marker for mask alignment constituted by a semiconductor film which is present on an insulating surface and an active layer of a thin film transistor, wherein the marker and the active layer are constituted by the same semiconductor film, and wherein said semiconductor film is thinner in at least a part of said active layer than in said marker.
Claim 57
Dependent Claim
67 words
A thin film semiconductor integrated circuit comprising a marker for mask alignment constituted by a semiconductor film which is present on an insulating surface and an active layer of a thin film transistor, wherein the marker and the active layer are constituted by the same semiconductor film, and wherein said semiconductor film is thinner in at least a part of said active layer than in said marker.
Claim 58
Dependent Claim
37 words
The circuit of claim 49 wherein a part of said semiconductor film containing said marker has a thickness of 400Å or more, and a channel-forming region of said active layer has a thickness of 300Å or less.
Claim 59
Dependent Claim
11 words
The circuit of claim 49 wherein said part comprises a channel.
Claim 60
Dependent Claim
15 words
The circuit of claim 51 wherein said channel has a thickness of 300Å or less.
Claim 61
Dependent Claim
13 words
The circuit of claim 49 wherein said semiconductor film is a crystalline film.
References Cited (Backward Citations)
JPS6185868A
Cited
JPH01134345A
Cited
JPH01194351A
Cited
US5147826A
Cited
JPH04170067A
Cited
JPH04313272A
Cited
US5275851A
Cited
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