Semiconductor device including via hole and isolating circumferential

Abstract

A semiconductor device includes a semiconductor element, such as a field effect transistor, and an adjacent connection region including a via hole. A simple structure prevents leakage current from flowing from a p-type buffer layer to a source electrode of the field effect transistor through a backside electrode and a via hole upper electrode, avoiding degradation in the gate-source dielectric resistance. A groove having a depth extending from a surface of an n-type semiconductor layer through a n-type semiconductor layer and a p-type buffer layer isolates a field effect transistor from a via hole that extends from the surface of an n-type semiconductor layer to a second surface of a compound semiconductor substrate. The groove prevents leakage current from flowing in a backside electrode in the via hole.