Field effect transistor

摘要

A field effect transistor with a high withstand voltage and a low resistance is provided. A ring-shaped channel region is disposed inside a source region formed in a ring, and the inside of the channel region is taken as a drain region. A depletion layer extends toward the inside of the drain region, resulting in a high withstand voltage. In the portion, except the portion within a prescribed distance from the corner portion of the channel region, a low resistance conductive layer is disposed, thereby resulting in high withstand voltage.