US5895935A
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Display device having a switch with floating regions in the active layer
Assignee: Semiconductor Energy Laboratory Co Ltd
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Filing: 1997-04-24
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Granted: 1999-04-20
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Expires: 2017-04-24
Abstract
Abstract A display device having high definition and high reliability, and technology for manufacturing the same. In an active matrix type display device of integrated peripheral driving circuit type, pixel TFTs of an active matrix circuit 100 are not provided with LDD regions. Also, among circuits constituting peripheral driving circuits 101, 102, buffer circuits, of which a high withstand voltage and high-speed operation are required, are made with thin film transistors having floating island regions and base regions between source and drain regions of their active layers.
Inventors
- 👤 Shunpei Yamazaki
- 👤 Hongyong Zhang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:47
CPC Classifications
H; H10; H10D; H10D86/00; H10D86/40; H10D30/00; H10D30/01; H10D30/021; H10D30/031; H10D30/0312; H10D30/0314; H10D30/0321; H10D30/60; H10D30/67; H10D30/6704; H10D30/6713; H10D30/6715; H10D30/6719; H10D30/6729; H10D30/673; H10D30/6733; H10D30/6737; H10D30/6739; H10D30/6757; H10D86/01; H10D86/021; H10D86/471; H10D86/60; H10P; H10P14/00; H10P14/20; H10P14/38; H10P14/3802; H10P14/3808; H10P14/29; H10P14/2901; H10P14/2921; H10P14/2922; H10P14/32; H10P14/3202; H10P14/3238; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P14/3806; H10P14/3816; H10P14/382
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
223 words
A display device comprising: an active matrix circuit located on a substrate, said active matrix circuit comprising at least a first thin film transistor therein; and a peripheral driving circuit located on said substrate, said peripheral driving circuit comprising at least second and third thin film transistors therein, said second thin film transistor having at least one of a structure and an operating principle essentially different from third thin film transistor, wherein at least one of said second and third thin film transistors has a source region, a floating island region, a base region and a drain region in an active layer thereof, said one of the second and third thin film transistors constituting a buffer circuit, each of said second and third thin film transistors having a conductivity type, wherein at least the other one of said second and third transistors comprises an n-channel thin film transistor and a p-channel transistor which are combined complementarily, and wherein said n-channel thin film transistor has an LDD region while said p-channel thin film transistor and said first thin film transistor do not have LDD regions, and wherein said floating island region of said one of the second and third thin film transistors has a same conductivity type as said source and drain regions of said one of the second and third thin film transistors.
Claim 2
Dependent Claim
223 words
A display device comprising: an active matrix circuit located on a substrate, said active matrix circuit comprising at least a first thin film transistor therein; and a peripheral driving circuit located on said substrate, said peripheral driving circuit comprising at least second and third thin film transistors therein, said second thin film transistor having at least one of a structure and an operating principle essentially different from third thin film transistor, wherein at least one of said second and third thin film transistors has a source region, a floating island region, a base region and a drain region in an active layer thereof, said one of the second and third thin film transistors constituting a buffer circuit, each of said second and third thin film transistors having a conductivity type, wherein at least the other one of said second and third transistors comprises an n-channel thin film transistor and a p-channel transistor which are combined complementarily, and wherein said n-channel thin film transistor has an LDD region while said p-channel thin film transistor and said first thin film transistor do not have LDD regions, and wherein said floating island region of said one of the second and third thin film transistors has a same conductivity type as said source and drain regions of said one of the second and third thin film transistors.
Claim 3
Dependent Claim
242 words
A display device having an active matrix circuit and a peripheral driving circuit of an insulating surface, said device comprising: at least first, second and third semiconductor island on said insulating surface; at least a first thin film transistor formed in said active matrix circuit, wherein said first thin film transistor comprises, a plurality of first channel regions formed in said first semiconductor island, a first source region and a first drain region formed in said first semiconductor island with the plurality of said first channel regions interposed therebetween, and a first gate electrode formed over said first channel regions; at least a second thin film transistor and a third thin film transistor in said peripheral driving circuit, wherein said second thin film transistor comprises, a base region and at least a floating island region formed in said second semiconductor island, said floating island region and said base region being contiguous each other, a second source region and a second drain region formed in said second semiconductor island with said base region and said floating island region therebetween, a second gate electrode formed over said base region and said floating island region, wherein said floating island region has a same conductivity type as said second source region and said second drain region; and wherein, said third thin film transistor comprises, only a third channel region formed in said third semiconductor island, only a third gate electrode formed over said third channel region.
Claim 4
Dependent Claim
242 words
A display device having an active matrix circuit and a peripheral driving circuit of an insulating surface, said device comprising: at least first, second and third semiconductor island on said insulating surface; at least a first thin film transistor formed in said active matrix circuit, wherein said first thin film transistor comprises, a plurality of first channel regions formed in said first semiconductor island, a first source region and a first drain region formed in said first semiconductor island with the plurality of said first channel regions interposed therebetween, and a first gate electrode formed over said first channel regions; at least a second thin film transistor and a third thin film transistor in said peripheral driving circuit, wherein said second thin film transistor comprises, a base region and at least a floating island region formed in said second semiconductor island, said floating island region and said base region being contiguous each other, a second source region and a second drain region formed in said second semiconductor island with said base region and said floating island region therebetween, a second gate electrode formed over said base region and said floating island region, wherein said floating island region has a same conductivity type as said second source region and said second drain region; and wherein, said third thin film transistor comprises, only a third channel region formed in said third semiconductor island, only a third gate electrode formed over said third channel region.
Claim 5
Dependent Claim
146 words
A display device comprising at least first, second and third semiconductor island on a insulating surface, wherein, said first semiconductor island comprises, a plurality of first channel regions formed in said first semiconductor island, a first gate insulating film formed adjacent to said first channel regions, a gate electrode formed on said first insulating film, and said second semiconductor island comprises, an active layer formed in said second semiconductor island, said active layer having a plurality of impurity regions and at least a portion, a second gate insulating film formed adjacent to said active layer, a second gate electrode adjacent to said second gate insulating film, wherein said portion has a different conductive type from said impurity regions, and said third semiconductor island comprises, only a third channel region formed in said third semiconductor island, only a third gate electrode formed over said third channel region.
Claim 6
Dependent Claim
146 words
A display device comprising at least first, second and third semiconductor island on a insulating surface, wherein, said first semiconductor island comprises, a plurality of first channel regions formed in said first semiconductor island, a first gate insulating film formed adjacent to said first channel regions, a gate electrode formed on said first insulating film, and said second semiconductor island comprises, an active layer formed in said second semiconductor island, said active layer having a plurality of impurity regions and at least a portion, a second gate insulating film formed adjacent to said active layer, a second gate electrode adjacent to said second gate insulating film, wherein said portion has a different conductive type from said impurity regions, and said third semiconductor island comprises, only a third channel region formed in said third semiconductor island, only a third gate electrode formed over said third channel region.
Claim 7
Dependent Claim
96 words
A display device having at least a thin film transistor comprising: a semiconductor island including, a base region and at least a floating island region in said semiconductor island, said base region and said floating island region being contiguous with each other, source and drain regions in said semiconductor island with said base region and said floating island region therebetween; and a gate electrode adjacent to said base region and said floating island region with a gate insulating film therebetween, wherein said floating island region has a same conductivity type as said source and drain regions.
Claim 8
Dependent Claim
96 words
A display device having at least a thin film transistor comprising: a semiconductor island including, a base region and at least a floating island region in said semiconductor island, said base region and said floating island region being contiguous with each other, source and drain regions in said semiconductor island with said base region and said floating island region therebetween; and a gate electrode adjacent to said base region and said floating island region with a gate insulating film therebetween, wherein said floating island region has a same conductivity type as said source and drain regions.
Claim 9
Dependent Claim
26 words
A display device according to claim 4 further comprising buffer circuit of said display device wherein said thin film transistor is formed in the buffer circuit.
Claim 10
Dependent Claim
121 words
A display device comprising: active matrix circuit; and a peripheral driver circuit for driving said active matrix circuit, wherein at least a thin film transistor is formed in said peripheral driver circuit, said thin film transistor including, a semiconductor island including, a base region and at least a floating island region in said semiconductor island, said base region and said floating island region being contiguous each other, source and drain regions in said semiconductor island with said base region and said floating island region therebetween, and a gate electrode adjacent to said base region and said floating island region with a gate insulating film therebetween, wherein said floating island region has a same conductivity type as said source and drain regions.
Claim 11
Dependent Claim
121 words
A display device comprising: active matrix circuit; and a peripheral driver circuit for driving said active matrix circuit, wherein at least a thin film transistor is formed in said peripheral driver circuit, said thin film transistor including, a semiconductor island including, a base region and at least a floating island region in said semiconductor island, said base region and said floating island region being contiguous each other, source and drain regions in said semiconductor island with said base region and said floating island region therebetween, and a gate electrode adjacent to said base region and said floating island region with a gate insulating film therebetween, wherein said floating island region has a same conductivity type as said source and drain regions.
Claim 12
Dependent Claim
40 words
A display device according to claim 6 further comprising: at least another thin film transistor in said active matrix circuit, said another thin film transistor having no LDD region, and at least a CMOS transistor in said peripheral driver circuit.
References Cited (Backward Citations)
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