Semiconductor device and display device including the same
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorSeiichi YONEDA
Life of this patent
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Abstract
A first transistor and a second transistor are stacked. The first transistor and the second transistor have a gate electrode in common. At least one of semiconductor films used in the first transistor and the second transistor is an oxide semiconductor film. With the use of the oxide semiconductor film as the semiconductor film in the transistor, high field-effect mobility and high-speed operation can be achieved. Since the first transistor and the second transistor are stacked and have the gate electrode in common, the area of a region where the transistors are disposed can be reduced.
Claims17
(canceled)
A display device comprising:
- a substrate;
- a pixel portion over the substrate;
- and
- a driver circuit over the substrate, the driver circuit comprising:
- a first transistor comprising:
- an oxide semiconductor layer comprising a channel formation region;
- a gate electrode overlapping with the channel formation region of the oxide semiconductor layer;
- and
- a gate insulating layer between the oxide semiconductor layer and the gate electrode;
- a first insulating layer in contact with a side surface of the gate electrode;
- and
- a second transistor comprising:
- a polycrystalline silicon layer comprising a channel formation region;
- and
- a second insulating layer between the polycrystalline silicon layer and the first insulating layer,
- wherein the channel formation region of the first transistor and the channel formation region of the second transistor overlap each other.
A display device comprising:
- a substrate;
- a driver circuit over the substrate;
- and
- a pixel portion over the substrate, the pixel portion comprising:
- a first transistor comprising:
- an oxide semiconductor layer comprising a channel formation region;
- a source electrode in contact with the oxide semiconductor layer;
- and
- a drain electrode in contact with the oxide semiconductor layer;
- and
- a second transistor comprising:
- a gate electrode;
- and
- a polycrystalline silicon layer comprising a channel formation region,
- wherein the gate electrode and the channel formation region of the polycrystalline silicon layer overlap each other, and
- wherein the source electrode and the drain electrode of the first transistor do not overlap the gate electrode of the second transistor.
A display device comprising:
- a substrate;
- a driver circuit over the substrate;
- and
- a pixel portion over the substrate, the pixel portion comprising:
- a first transistor comprising:
- an oxide semiconductor layer comprising a channel formation region;
- a source electrode in contact with the oxide semiconductor layer;
- and
- a drain electrode in contact with the oxide semiconductor layer;
- and
- a second transistor comprising:
- a gate electrode;
- and
- a polycrystalline silicon layer comprising a channel formation region,
- wherein the gate electrode and the channel formation region of the polycrystalline silicon layer overlap each other,
- wherein the source electrode and the drain electrode of the first transistor do not overlap the gate electrode of the second transistor, and
- wherein the channel formation region of the first transistor and the channel formation region of the second transistor overlap each other.
Dependencies are inferred from the claim text.