Abstract: According to one embodiment, a semiconductor device includes a semiconductor substrate with a p-type conductivity, a buried layer with an n-type conductivity provided on the semiconductor substrate, a back gate layer with a p-type conductivity provided on the buried layer, a drain layer with an n-type conductivity provided on the back gate layer, a source layer with an n-type conductivity provided spaced from the drain layer, a gate electrode provided in a region immediately above a portion of the back gate layer between the drain layer and the source layer, and a drain electrode in contact with a part of an upper surface of the drain layer. A thickness of the drain layer in a region immediately below a contact surface between the drain layer and the drain electrode is half a total thickness of the back gate and drain layers in the region.

Abstract: According to one embodiment, a semiconductor device includes a semiconductor substrate with a p-type conductivity, a buried layer with an n-type conductivity provided on the semiconductor substrate, a back gate layer with a p-type conductivity provided on the buried layer, a drain layer with an n-type conductivity provided on the back gate layer, a source layer with an n-type conductivity provided spaced from the drain layer, a gate electrode provided in a region immediately above a portion of the back gate layer between the drain layer and the source layer, and a drain electrode in contact with a part of an upper surface of the drain layer. A thickness of the drain layer in a region immediately below a contact surface between the drain layer and the drain electrode is half a total thickness of the back gate and drain layers in the region.