Abstract
A nitride-type semiconductor device comprises a substrate, a buffer body, a first nitride semiconductor layer, a second nitride semiconductor layer, a gate electrode, a first source/drain electrode, and a second source/drain electrode. The buffer body is disposed on the substrate and comprises at least one layer of a nitride semiconductor compound. The nitride semiconductor compound is doped with an acceptor and is located at the topmost part of the buffer body. The first nitride semiconductor layer is arranged on the buffer body. The second nitride semiconductor layer is arranged on the first nitride semiconductor layer. The gate electrode, the first source/drain electrode, and the second source/drain electrode are arranged on the second nitride semiconductor layer. A contour of the first source/drain electrode and a contour of the second source/drain electrode exhibit asymmetry with respect to the gate such that a bottom surface of the first source/drain electrode is deeper with respect to the gate electrode than a bottom surface of the second source/drain electrode.