Semiconductor device

Abstract

Inside an IGBT using GaN or SiC, light having an energy of approximately 3 [eV] is generated. Therefore, defects are caused in the gate insulating film of the IGBT. Furthermore, the charge trapped at a deep level becomes excited and moves to the channel region, thereby causing the gate threshold voltage to fluctuate from the predetermined value. Provided is a semiconductor device including a normally-ON semiconductor element that includes a first semiconductor layer capable of conductivity modulation and a first gate electrode, but does not include a gate insulating film between the first gate electrode and the first semiconductor layer; and a normally-OFF semiconductor element that includes a second semiconductor layer, a second gate electrode, and a gate insulating film between the second semiconductor layer and the second gate electrode. The normally-ON semiconductor element and the normally-OFF semiconductor element are connected in series.

Dependencies are inferred from the claim text.