SEMICONDUCTOR DEVICE AND METHOD MANUFACTURING THE SAME

摘要

According to one embodiment of the present invention, a semiconductor element includes: an n+ type silicon carbide substrate; an n- type epi layer, a p type epi layer and an n+ region which are arranged in order on the first surface of the n+ type silicon carbide substrate; a trench which penetrates the n+ region and the p type epi layer and is placed on the n- type epi layer; a gate insulation film which is placed inside the trench on the n+ region and the p type epi layer; a gate electrode which is placed on the gate insulation film placed inside the trench; an oxide film which is placed on the gate electrode; a buffer layer which is placed on the gate insulation film placed on the n+ region and the p type epi layer; a source electrode which is placed on the buffer layer and the oxide film; and a drain electrode which is placed on the second surface of the n+ type silicon carbide substrate. The buffer is made of polycrystalline silicon.