Patent ID: 8502310

Claim:
A III nitride semiconductor electronic device comprising: a support base of a III nitride semiconductor having a carrier concentration of more than 1×10 18 cm −3 , the support base including a first face and a second face opposite to the first face; and a first III nitride semiconductor epitaxial layer provided on the first face of the support base, the first III nitride semiconductor epitaxial layer making a junction with the first face of the support base, the first face of the support base being inclined at an angle of more than 5 degrees with respect to a reference axis, and the reference axis extending in a direction of a c-axis of the III nitride semiconductor, the first III nitride semiconductor epitaxial layer including first, second and third regions arranged in order in a direction of a normal to the first face, a dislocation density of the second region being smaller than a dislocation density of the support base, and a dislocation density of the third region being smaller than a dislocation density of the first region.