SEMICONDUCTOR DEVICE

PROBLEM TO BE SOLVED: To provide a semiconductor device composed of a group III-V nitride semiconductor that reduces loss of a high-frequency signal caused on a substrate, and improves high-frequency output and linearity of output electric power. SOLUTION: The semiconductor device composed of the group III-V nitride semiconductor includes a cover 116 for packaging, a ground conductor layer 118 formed on a bottom surface of the cover 116 for packaging, a high dielectric constant film 114 formed on the ground conductor layer 118, a back electrode 113 formed on the high dielectric constant film 114 and being not in contact with the ground conductor layer 118, the substrate 101 arranged on the back electrode 113 and made of silicon, a channel layer 103 and a Schottky layer 104 formed on the substrate 101, and a bias electrode 119 formed on the bottom surface of the cover 116 for packaging and being not in contact with the ground conductor layer 118, wherein the back electrode 113 is electrically connected to a bias electrode 119. COPYRIGHT: (C)2010,JPO&INPIT