Projection TV
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsShunpei Yamazaki, Hisashi Ohtani, Masahiko Hayakawa
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Abstract
Thin-film transistors constituting a liquid crystal module have a channel forming region that is a crystal structural body in which a plurality of rod-like or flat-rod-like crystals are arranged in a particular direction. In the thin-film transistors, deteriorations in device characteristics due to hot carrier injection or the like can be prevented effectively when the temperature is in a range of 80° C.-250° C. (preferably 100° C.-200° C.). Therefore, a projection TV that is very high in reliability can be realized.
Claims27
A projection TV having at least an optical system and at least one liquid crystal module, said liquid crystal module having a plurality of thin-film transistors formed over a substrate having an insulating surface,
- wherein each of said thin-film transistors has a channel forming region that is a crystal structural body in which a plurality of rod-like or flat-rod-like crystals are arranged approximately parallel with each other in a particular direction, and
- wherein said thin-film transistors have an operation temperature of 80° C.-250° C.
A projection TV having at least an optical system and at least one liquid crystal module, said liquid crystal module having a plurality of thin-film transistors formed over a substrate having an insulating surface,
- wherein each of said thin-film transistors has a channel forming region that is a crystal structural body in which a plurality of rod-like or flat-rod-like crystals are arranged approximately parallel with each other in a particular direction and crystal lattices are continuous at most of grain boundaries, and
- wherein said thin-film transistors have an operation temperature of 80° C.-250° C.
A projection-type display device having at least an optical system and at least one liquid crystal module having a pixel matrix circuit, at least one driver circuit, and a logic circuit over a substrate, said pixel matrix circuit comprising:
- at least one active layer comprising crystalline semiconductor film over an insulating surface of said substrate, said active layer having at least channel, source, and drain regions of a thin-film transistor;
- a gate electrode adjacent to said active layer with an gate insulating film therebetween;
- and
- an auxiliary capacitor composed of a part of said drain region, a capacitor electrode, a layer disposed between said part of the drain region and said capacitor electrode,
- wherein said capacitor electrode comprises the same material as the gate electrode and said layer comprises the same material as the gate insulating film.
A projection-type display device having at least an optical system and at least one liquid crystal module having a pixel matrix circuit, at least one driver circuit, and a logic circuit over a substrate, said pixel matrix circuit comprising:
- at least one active layer of a thin-film transistor comprising crystalline semiconductor film over an insulating surface of said substrate, said active layer having at least channel, source, and drain regions of said thin-film transistor;
- a gate electrode adjacent to said active layer with an gate insulating film therebetween;
- a drain electrode connected with said drain region disposed over the thin-film transistor;
- and
- a black mask disposed between said thin-film transistor and a, pixel electrode after;
- wherein an auxiliary capacitor of the pixel matrix circuit is composed of said drain electrode, said black mask, and a layer disposed between said drain electrode and said black mask.
Dependencies are inferred from the claim text.