| 摘要 |
A semiconductor device that includes an oxide semiconductor and is suitable for a power device having an ability to allow large current to flow therein. The semiconductor device includes: a first electrode having an opening and a second electrode provided in the opening of the first electrode and separated from the first electrode, over the semiconductor layer; a gate insulating layer over the first electrode, the second electrode, and the semiconductor layer; and a ring-shaped gate electrode over the gate insulating layer. An inner edge portion of the ring-shaped gate electrode overlaps the second electrode, while an outer edge portion of the ring-shaped gate electrode overlaps a part of the oxide semiconductor layer, which is located between the first electrode and the second electrode. An element imparting conductivity to the oxide semiconductor layer is added to the part. |
| 主权项 |
1. A semiconductor device comprising:
a semiconductor layer comprising a first layer, a second layer, and a third layer; a gate electrode; and a gate insulating layer sandwiched between the semiconductor layer and the gate electrode, wherein the second layer is sandwiched between the first layer and the third layer, wherein the first layer, the second layer, and the third layer satisfy the following relationship:
EcS1,EcS3>EcS2, where EcS1, EcS2, and EcS3 are energies of bottoms of conduction bands of the first layer, the second layer, and the third layer, respectively, and wherein the second layer comprises an oxide semiconductor. |
