Semiconductor device has an oxide semiconductor layer containing a c-axis aligned crystal
View Patent ↗A semiconductor device includes an oxide semiconductor layer including a crystalline region over an insulating surface, a source electrode layer and a drain electrode layer in contact with the oxide semiconductor layer, a gate insulating layer covering the oxide semiconductor layer, the source electrode layer, and the drain electrode layer, and a gate electrode layer over the gate insulating layer in a region overlapping with the crystalline region. The crystalline region includes a crystal whose c-axis is aligned in a direction substantially perpendicular to a surface of the oxide semiconductor layer.
1. A semiconductor device comprising:
an oxide semiconductor layer comprising channel formation region including a crystalline region over a substrate,
wherein the oxide semiconductor layer comprises indium, gallium, and zinc, and
wherein the crystalline region has c-axis aligned in a direction substantially perpendicular to a surface of the oxide semiconductor layer.
2. The semiconductor device according to claim 1 , further comprising a source electrode layer electrically connected to the oxide semiconductor layer and a drain electrode layer electrically connected to the oxide semiconductor layer; and
a first gate electrode layer below the oxide semiconductor layer with a first insulating layer therebetween.
3. The semiconductor device according to claim 2 , further comprising a second gate electrode layer over the oxide semiconductor layer with a second insulating layer therebetween.
4. The semiconductor device according to claim 1 , further comprising a source electrode layer electrically connected to the oxide semiconductor layer and a drain electrode layer electrically connected to the oxide semiconductor layer; and
a second gate electrode layer over the oxide semiconductor layer with a second insulating layer therebetween.
5. The semiconductor device according to claim 1 , wherein the crystalline region has a shape of a thin plate.
6. The semiconductor device according to claim 1 , wherein the crystalline region extends from the surface of the oxide semiconductor layer in the direction substantially perpendicular to the surface of the oxide semiconductor layer.
7. A semiconductor device comprising:
an oxide semiconductor layer comprising channel formation region including a crystalline region over a substrate,
wherein the oxide semiconductor layer comprises indium, gallium, and zinc, and
wherein the crystalline region comprises a plurality of crystals with c-axis substantially parallel to each other.
8. The semiconductor device according to claim 7 , further comprising a source electrode layer electrically connected to the oxide semiconductor layer and a drain electrode layer electrically connected to the oxide semiconductor layer; and
a first gate electrode layer below the oxide semiconductor layer with a first insulating layer therebetween.
9. The semiconductor device according to claim 7 , further comprising a source electrode layer electrically connected to the oxide semiconductor layer and a drain electrode layer electrically connected to the oxide semiconductor layer; and
a second gate electrode layer over the oxide semiconductor layer with a second insulating layer therebetween.
10. The semiconductor device according to claim 8 , further comprising a second gate electrode layer over the oxide semiconductor layer with a second insulating layer therebetween.
11. The semiconductor device according to claim 7 , wherein each of the plurality of crystals has a shape of a thin plate.
12. The semiconductor device according to claim 7 , wherein the crystalline region extends from a surface of the oxide semiconductor layer in a direction substantially perpendicular to the surface of the oxide semiconductor layer.