Active matrix display device with TFTs of different refractive index
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsShunpei Yamazaki, Naoto Kusumoto, Koichiro Tanaka
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Abstract
In producing a semiconductor device by annealing with laser light irradiation, while a linear laser light is scanned in a direction perpendicular to a line, the annealing is performed for a semiconductor material. In this state, since an anneal effect in a beam lateral direction corresponding to a line direction is 2 times or more different than that in the scanning direction, a plurality of semiconductor elements are formed along a line direction in which the linear laser light is irradiated. Also, a line direction connecting the source and drain region of a thin film transistor is aligned to the line direction of the linear laser light.
Claims50
A semiconductor device having at least first thin film transistors arranged in a first direction and second thin film transistors arranged in a second direction perpendicular to the first direction formed over a same substrate, each of said first and second thin film transistors comprising:
- a crystalline semiconductor film formed on an insulating surface;
- a channel region formed in said crystalline semiconductor film;
- source and drain regions formed in said crystalline semiconductor film wherein carriers flow through said channel region between said source and drain regions in a direction parallel to the first direction;
- at least one gate electrode formed adjacent to said channel region with a gate insulating film interposed therebetween, and
- wherein variation of refractive indexes of said channel regions in said second thin film transistors is more than two times larger than that of said first thin film transistors.
A semiconductor device having at least first thin film transistors arranged in a first direction and second thin film transistors arranged in a second direction perpendicular to the first direction over a same substrate, each of said first and second thin film transistors comprising:
- a crystalline semiconductor film formed on an insulating surface;
- a channel region formed in said crystalline semiconductor film;
- source and drain regions formed in said crystalline semiconductor film wherein carriers flow through said channel region between said source and drain regions;
- at least one gate electrode formed adjacent to said channel region with a gate insulating film interposed therebetween, and
- wherein variation of refractive indexes of said channel regions in said second thin film transistors is larger than that of said first thin film transistors.
A semiconductor device having at least first thin film transistors arranged in a first direction and second thin film transistors arranged in a second direction perpendicular to the first direction over a same substrate, each of said first and second thin film transistors comprising:
- a crystalline semiconductor film formed on an insulating surface, wherein said crystalline semiconductor film is obtained by an irradiation of a linear-shaped laser beam having an elongated cross section while moving said substrate in a direction orthogonal to an elongation direction of the cross section;
- a channel region formed in said crystalline semiconductor film;
- source and drain regions formed in said crystalline semiconductor film wherein carriers flow through said channel region in a direction parallel to the first direction;
- at least one gate electrode formed adjacent to said channel region with a gate insulating film interposed therebetween, and wherein variation of refractive indexes of said channel regions in said second thin film transistors is more than two times larger than that of said first thin film transistors.
A semiconductor device having at least first thin film transistors arranged in a first direction and second thin film transistors arranged in a second direction perpendicular to the first direction, each of said first and second thin film transistors comprising:
- a crystalline semiconductor film formed on an insulating surface, wherein said crystalline semiconductor film is obtained by an irradiation of a linear-shaped laser beam having an elongated cross section while moving said substrate in a direction orthogonal to an elongation direction of the cross section;
- a channel region formed in said crystalline semiconductor film;
- source and drain regions formed in said crystalline semiconductor film wherein carriers flow through said channel between said source and drain regions;
- at least one gate electrode formed adjacent to said channel region with a gate insulating film interposed therebetween, and
- wherein variation of refractive indexes of said channel regions in said second thin film transistors is larger than that of said first thin film transistors.
A display device having an active matrix region including at least first thin film transistors arranged in a first direction and second thin film transistors arranged in a second direction perpendicular to the first direction over a same substrate, each of said first and second thin film transistors comprising:
- a crystalline semiconductor film formed on an insulating surface;
- a channel region formed in said crystalline semiconductor film;
- source and drain regions formed in said crystalline semiconductor film wherein carriers flow through said channel region between said source and drain regions in a direction parallel to the first direction;
- at least one gate electrode formed adjacent to said channel region with a gate insulating film interposed therebetween, and
- wherein variation of refractive indexes of said channel regions in said second thin film transistors is more than two times larger than that of said first thin film transistors.
A display device having an active matrix region including at least first thin film transistors arranged in a first direction and second thin film transistors arranged in a second direction perpendicular to the first direction over a same substrate, each of said first and second thin film transistors comprising:
- a crystalline semiconductor film formed on an insulating surface;
- a channel region formed in said crystalline semiconductor film;
- source and drain regions formed in said crystalline semiconductor film wherein carriers flow through said channel region between said source and drain regions;
- at least one gate electrode formed adjacent to said channel region with a gate insulating film interposed therebetween, and
- wherein variation of refractive indexes of said channel regions in said second thin film transistors is larger than that of said first thin film transistors.
An active matrix display device having a shift register including at least first thin film transistors arranged in a first direction and second thin film transistors arranged in a second direction perpendicular to the first direction over a same substrate, each of said first and second thin film transistors comprising:
- a crystalline semiconductor film formed on an insulating surface;
- a channel region formed in said crystalline semiconductor film;
- source and drain regions formed in said crystalline semiconductor film wherein carriers flow through said channel region between said source and drain regions in a direction parallel to the first direction;
- at least one gate electrode formed adjacent to said channel region with a gate insulating film interposed therebetween, and
- wherein variation of refractive indexes of said channel regions in said second thin film transistors is more than two times larger than that of said first thin film transistors.
An active matrix display device having a shift register including at least first thin film transistors arranged in a first direction and second thin film transistors arranged in a second direction perpendicular to the first direction, each of said first and second thin film transistors comprising:
- a crystalline semiconductor film formed over a substrate having an insulating surface;
- a channel region formed in said crystalline semiconductor film;
- source and drain regions formed in said crystalline semiconductor film wherein carriers flow through said channel region between said source and drain regions;
- at least one gate electrode formed adjacent to said channel region with a gate insulating film interposed therebetween, and
- wherein variation of refractive indexes of said channel regions in said second thin film transistors is larger than that of said first thin film transistors.
An active matrix display device having a buffer circuit including at least first thin film transistors arranged in a first direction and second thin film transistors arranged in a second direction perpendicular to the first direction over a same substrate, each of said first and second thin film transistors comprising:
- a crystalline semiconductor film formed on an insulating surface;
- a channel region formed in said crystalline semiconductor film;
- source and drain regions formed in said crystalline semiconductor film wherein carriers flow through said channel region between said source and drain regions in a direction parallel to the first direction;
- at least one gate electrode formed adjacent to said channel region with a gate insulating film interposed therebetween, and
- wherein variation of refractive indexes of said channel regions in said second thin film transistors is more than two times larger than that of said first thin film transistors.
An active matrix display device having a buffer circuit including at least first thin film transistors arranged in a first direction and second thin film transistors arranged in a second direction perpendicular to the first direction over a same substrate, each of said first and second thin film transistors comprising:
- a crystalline semiconductor film formed on an insulating surface;
- a channel region formed in said crystalline semiconductor film;
- source and drain regions formed in said crystalline semiconductor film wherein carriers flow through said channel region between said source and drain regions;
- at least one gate electrode formed adjacent to said channel region with a gate insulating film interposed therebetween, and
- wherein variation of refractive indexes of said channel regions in said second thin film transistors is larger than that of said first thin film transistors.
Dependencies are inferred from the claim text.