Group III Nitride Semiconductor Device and Epitaxial Substrate

摘要

Affords a Group III nitride semiconductor device having a structure that can improve the breakdown voltage. A Schottky diode (11) consists of a Group III nitride support substrate (13), a gallium nitride region (15), and a Schottky electrode (17). The Group III nitride support substrate (13) has electrical conductivity. The Schottky electrode (17) forms a Schottky junction on the gallium nitride region (15). The gallium nitride region (15) is fabricated on a principal face (13a) of the Group III nitride support substrate (13). The gallium nitride region (15) has a (10 <o ostyle="single">12)-plane XRD full-width-at-half-maximum of 100 sec or less.