Patent ID: 8698198
Filing Date: 2014-04-15
Classification: H01L

Abstract:
1. A nitride semiconductor device comprising: a first nitride semiconductor layer formed of non-doped Al a second nitride semiconductor layer in direct contact with and directly adjacent the first nitride semiconductor layer of non-doped or n-type Al a third nitride semiconductor layer in direct contact with and directly adjacent the second nitride semiconductor layer of a non-doped or n-type nitride semiconductor, the third nitride semiconductor layer being a single layer and having a lattice constant equal to that of the first nitride semiconductor layer; a fourth nitride semiconductor layer in direct contact with and directly adjacent the third nitride semiconductor layer of In a gate electrode formed in a recess structure that passes through the fourth nitride semiconductor layer and that has a bottom face located in the third nitride semiconductor layer such that a thickness of the third nitride semiconductor layer remains under the gate electrode; a source electrode and a drain electrode formed on the second nitride semiconductor layer, the third nitride semiconductor layer, or the fourth nitride semiconductor layer so as to sandwich the gate electrode therebetween, and wherein a polarization charge on the surface of the third nitride layer facing the second nitride layer is negative and a polarization charge on the surface of the third nitride layer in contact with the fourth nitride layer is positive.