US5677549A
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US
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Semiconductor device having a plurality of crystalline thin film transistors
Assignee: Semiconductor Energy Laboratory Co Ltd
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Filing: 1995-05-12
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Granted: 1997-10-14
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Expires: 2015-05-12
Abstract
Abstract A semiconductor circuit having a plurality of crystalline thin film transistors possessing different electrical characteristics which are formed on a substrate having an active matrix region and a driver circuit region. At least one first thin film transistor comprising a first crystalline silicon film is formed on the active matrix region of the substrate, while at least one second thin film transistor comprising a second crystalline silicon film is formed on the driver circuit region. The crystalline film of each of the first thin film transistors contains a catalyst element capable of promoting the crystallization of silicon at a higher concentration than the crystalline film of each of the second thin film transistors.
Inventors
- 👤 Toru Takayama
- 👤 Hongyong Zhang
- 👤 Yasuhiko Takemura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:31
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/20; H10P14/38; H10P14/3802; H10P14/3808; H10P14/3816; H10D; H10D86/00; H10D86/01; H10D86/021; H10D86/0221; H10D86/0223; H10D86/0225; H10D86/40; H10D86/421; H10D86/425; H10D86/60; H10P14/29; H10P14/2901; H10P14/2922; H10P14/32; H10P14/3202; H10P14/3238; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P14/3806
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
125 words
An active matrix device comprising: a substrate having an active matrix region and a driver circuit region; a first plurality of thin film transistors formed on said active matrix region of the substrate, each of said transistors having a crystalline semiconductor film comprising silicon as an active region; and a second plurality of thin film transistors formed on said driver circuit region, each of said transistors having a crystalline semiconductor film comprising silicon as an active region, wherein the crystalline semiconductor film of each of said first plurality of thin film transistors contains a catalyst element at a higher concentration than the crystalline semiconductor film of each of said second plurality of thin film transistors, said catalyst element capable of promoting a crystallization of silicon.
Claim 2
Dependent Claim
125 words
An active matrix device comprising: a substrate having an active matrix region and a driver circuit region; a first plurality of thin film transistors formed on said active matrix region of the substrate, each of said transistors having a crystalline semiconductor film comprising silicon as an active region; and a second plurality of thin film transistors formed on said driver circuit region, each of said transistors having a crystalline semiconductor film comprising silicon as an active region, wherein the crystalline semiconductor film of each of said first plurality of thin film transistors contains a catalyst element at a higher concentration than the crystalline semiconductor film of each of said second plurality of thin film transistors, said catalyst element capable of promoting a crystallization of silicon.
Claim 3
Dependent Claim
38 words
The active matrix device of claim 1 wherein the crystalline semiconductor film of each of said first plurality of thin film transistors contains said catalyst element at a concentration of 1×10 17 to 1×10 20 atoms/cm 3 .
Claim 4
Dependent Claim
17 words
The active matrix device of claim 2 wherein said concentration is defined by a measurement of SIMS.
Claim 5
Dependent Claim
95 words
A semiconductor device comprising: a substrate; a first circuit comprising a p-channel thin film transistor and an n-channel thin film transistor formed on said substrate; and a second circuit comprising thin film transistors of only one of p-channel or n-channel types formed on said substrate, wherein each of said transistors of both said first and second circuits has a crystalline semiconductor film comprising silicon as an active region, and the thin film transistors of said second circuit contains a crystallization promoting material at a higher concentration than the thin film transistors of said first circuit.
Claim 6
Dependent Claim
95 words
A semiconductor device comprising: a substrate; a first circuit comprising a p-channel thin film transistor and an n-channel thin film transistor formed on said substrate; and a second circuit comprising thin film transistors of only one of p-channel or n-channel types formed on said substrate, wherein each of said transistors of both said first and second circuits has a crystalline semiconductor film comprising silicon as an active region, and the thin film transistors of said second circuit contains a crystallization promoting material at a higher concentration than the thin film transistors of said first circuit.
Claim 7
Dependent Claim
21 words
The device of claim 4 wherein said p-channel thin film transistor and said n-channel thin film transistor form a CMOS device.
Claim 8
Dependent Claim
75 words
A semiconductor device comprising: a substrate a first thin film transistor comprising a first crystalline silicon film formed on said substrate; and a second thin film transistor comprising a second crystalline silicon film formed on said substrate, wherein said first thin film transistor is doped with a catalyst metal which is capable of promoting a crystallization of said first crystalline silicon film while said second crystalline silicon film is not doped with said catalyst metal.
Claim 9
Dependent Claim
75 words
A semiconductor device comprising: a substrate a first thin film transistor comprising a first crystalline silicon film formed on said substrate; and a second thin film transistor comprising a second crystalline silicon film formed on said substrate, wherein said first thin film transistor is doped with a catalyst metal which is capable of promoting a crystallization of said first crystalline silicon film while said second crystalline silicon film is not doped with said catalyst metal.
Claim 10
Dependent Claim
26 words
The semiconductor device of claim 6 wherein said first thin film transistor contains said catalyst element at a higher concentration than said second thin film transistor.
Claim 11
Dependent Claim
75 words
A semiconductor circuit comprising: a monolithic circuit comprising an active matrix circuit and a peripheral driver circuit provided on a substrate, wherein an active region of a transistor provided in said active matrix circuit contains a catalytic element at a concentration of 1×10 17 cm -3 or higher, and concentration of said catalytic element in an active region of a transistor provided in said peripheral driver circuit is lower than 1×10 17 cm -3 .
Claim 12
Dependent Claim
75 words
A semiconductor circuit comprising: a monolithic circuit comprising an active matrix circuit and a peripheral driver circuit provided on a substrate, wherein an active region of a transistor provided in said active matrix circuit contains a catalytic element at a concentration of 1×10 17 cm -3 or higher, and concentration of said catalytic element in an active region of a transistor provided in said peripheral driver circuit is lower than 1×10 17 cm -3 .
Claim 13
Dependent Claim
32 words
The circuit of claim 8 wherein said active region of the transistor provided in said active matrix circuit contains said catalytic element at a concentration of 5×10 18 cm -3 or higher.
Claim 14
Dependent Claim
33 words
The circuit of claim 8 wherein said concentration of said catalytic element in the active region of the transistor provided in said peripheral driver circuit is lower than 1×10 16 cm -3 .
Claim 15
Dependent Claim
25 words
The circuit of claim 8 wherein said catalytic element is at least one element selected from the group consisting of nickel, iron, cobalt, and platinum.
Claim 16
Dependent Claim
24 words
The circuit of claim 8 wherein the concentration of the catalytic element is defined by a minimum value obtained by secondary ion mass spectroscopy.
Claim 17
Dependent Claim
35 words
The circuit of claim 11 wherein a total concentration of nickel, iron, cobalt, and platinum is 1×10 20 cm -3 or lower in said active region of the transistor provided in said active matrix circuit.
Claim 18
Dependent Claim
68 words
A semiconductor circuit comprising: a plurality of thin film transistors provided on a substrate, wherein an active region of a first one of said thin film transistors contains a catalytic element at a concentration of 1×10 17 cm -3 or higher, and concentration of said catalytic element in an active region of a second one of said thin film transistors is lower than 1×10 17 cm -3 .
Claim 19
Dependent Claim
68 words
A semiconductor circuit comprising: a plurality of thin film transistors provided on a substrate, wherein an active region of a first one of said thin film transistors contains a catalytic element at a concentration of 1×10 17 cm -3 or higher, and concentration of said catalytic element in an active region of a second one of said thin film transistors is lower than 1×10 17 cm -3 .
References Cited (Backward Citations)
US4571486A
Cited
US4986213A
Cited
US4772927A
Cited
US5147826A
Cited
US5236850A
Cited
US5156914A
Cited
US5352291A
Cited
US5352291B1
Cited
US5328861A
Cited
US5374837A
Cited
US5252502A
Cited
US5275851A
Cited
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| 3.5 Years (Year 4) | 2000-10-13 | 2001-04-14 | 2001-10-14 | $2000.00 | Window Closed / Lapsed |
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