Method of manufacturing thin film transistor

An organic electroluminescence display device comprising:

• a substrate;
• at least first and second pixels arranged adjacent to each other over the substrate, each pixel comprising:
• a switching thin film transistor and a current control thin film transistor formed over the substrate;
• and
• an EL element electrically connected to said current control thin film transistor, said EL element comprising a light emitting layer comprising an organic material;
• a first wiring extending along a first direction and electrically connected to a gate electrode of the switching thin film transistor of both the first and second pixels;
• a second wiring extending across said first wiring and electrically connected to said switching thin film transistor of the first pixel;
• a third wiring extending across said first wiring and electrically connected to said switching thin film transistor of the second pixel;
• a fourth wiring extending in parallel with said second and third wirings and electrically connected to the current control thin film transistors of both the first and second pixels, wherein said current control thin film transistor comprises:
• a crystalline semiconductor layer formed over the substrate and including at least a channel region, source and drain regions and a pair of lightly doped regions between the channel region and said source and drain regions;
• a gate insulator formed on the crystalline semiconductor layer;
• and
• a gate electrode formed over the channel region with the gate insulator interposed therebetween wherein boundaries between said channel region and said pair of lightly doped regions are aligned with side edges of the gate electrode.

An organic electroluminescence display device comprising:

• a substrate;
• at least first and second pixels arranged adjacent to each other over the substrate, each pixel comprising:
• a switching thin film transistor and a current control thin film transistor formed over the substrate;
• and
• an EL element electrically connected to said current control thin film transistor, said EL element comprising a light emitting layer comprising an organic material;
• a first wiring extending along a first direction and electrically connected to a gate electrode of the switching thin film transistor of both the first and second pixels;
• a second wiring extending across said first wiring and electrically connected to said switching thin film transistor of the first pixel;
• a third wiring extending across said first wiring and electrically connected to said switching thin film transistor of the second pixel;
• a current supply line extending in parallel with said second and third wirings and electrically connected to the current control thin film transistors of both the first and second pixels,
• wherein said current control thin film transistor comprises:
• a crystalline semiconductor layer formed over the substrate and including at least a channel region, source and drain regions and a pair of lightly doped regions between the channel region and said source and drain regions;
• a gate insulator formed on the crystalline semiconductor layer;
• and
• a gate electrode formed over the channel region with the gate insulator interposed therebetween wherein boundaries between said channel region and said pair of lightly doped regions are aligned with side edges of the gate electrode.

An electroluminescence display device comprising:

• a substrate;
• at least first and second pixels arranged adjacent to each other over the substrate, each pixel comprising:
• a switching thin film transistor and a current control thin film transistor formed over the substrate wherein a gate electrode of the current control thin film transistor is electrically connected to said switching thin film transistor;
• and
• an EL element electrically connected to said current control thin film transistor, said EL element comprising a light emitting layer comprising an organic material;
• a first wiring extending along a first direction and electrically connected to a gate electrode of the switching thin film transistor of both the first an second pixels;
• a second wiring extending across said first wiring and electrically connected to said switching thin film transistor of the first pixel;
• a third wiring extending across said first wiring and electrically connected to said switching thin film transistor of the second pixel;
• a current supply line extending in parallel with said second and third wirings and electrically connected to the current control thin film transistors of both the first and second pixels.

An organic electroluminescence display device comprising:

• a substrate;
• at least first and second pixels arranged adjacent to each other over the substrate, each pixel comprising:
• a switching thin film transistor and a current control thin film transistor formed over the substrate wherein a gate electrode of the current control thin film transistor is electrically connected to said switching thin film transistor;
• and
• an EL element electrically connected to said current control thin film transistor, said EL element comprising a light emitting layer comprising an organic material;
• a first wiring extending along a first direction and electrically connected to a gate electrode of the switching thin film transistor of both the first and second pixels;
• a second wiring extending across said first wiring and electrically connected to said switching thin film transistor of the first pixel;
• a third wiring extending across said first wiring and electrically connected to said switching thin film transistor of the second pixel;
• a current supply line extending in parallel with said second and third wirings and electrically connected to the current control thin film transistors of both the first and second pixels,
• wherein said current control thin film transistor comprises:
• a crystalline semiconductor layer formed over the substrate and including at least a channel region, source and drain regions and a pair of lightly doped regions between the channel region and said source and drain regions;
• a gate insulator formed on the crystalline semiconductor layer;
• and
• a gate electrode formed over the channel region with the gate insulator interposed therebetween wherein boundaries between said channel legion and said pair of lightly doped regions are aligned with side edges of the gate electrode.

An organic electroluminescence display device comprising:

• a substrate;
• at least first and second pixels arranged adjacent to each other over the substrate, each pixel comprising:
• a switching thin film transistor and a current control thin film transistor formed over the substrate wherein a gate electrode of the current control thin film transistor is electrically connected to said switching thin film transistor;
• and
• an EL element electrically connected to said current control thin film transistor, said EL element comprising a light emitting layer comprising an organic material;
• a first wiring extending along a first direction and electrically connected to a gate electrode of the switching thin film transistor of both the first and second pixels;
• a second wiring extending across said first wiring and electrically connected to said switching thin film transistor of the first pixel;
• a third wiring extending across said first wiring and electrically connected to said switching thin film transistor of the second pixel;
• a current supply line extending in parallel with said second and third wirings and electrically connected to the current control thin film transistors of both the first and second pixels,
• wherein said current control thin film transistor comprises:
• a crystalline semiconductor layer formed over the substrate and including at least a channel region, source and drain regions and a pair of lightly doped regions between the channel region and said source and drain regions;
• a gate insulator formed on the crystalline semiconductor layer;
• and
• a gate electrode formed over the channel region with the gate insulator interposed therebetween wherein boundaries between said channel region and said pair of lightly doped regions are aligned with side edges of the gate electrode, and
• wherein said current control transistor is an n-type thin film transistor.