Manufacturing method of silicon carbide semiconductor device

Abstract

In producing a MOS silicon carbide semiconductor device, after a first heat treatment (oxynitride) is performed in an oxidation atmosphere including nitrous oxide or nitric oxide, a second heat treatment including hydrogen is performed, whereby in the front surface of a SiC epitaxial substrate, a gate insulating film is formed. A gate electrode is formed and after an interlayer insulating film is formed, a third heat treatment is performed to bake the interlayer insulating film. After contact metal formation, a fourth heat treatment is performed to form a reactive layer of contact metal and the silicon carbide semiconductor. The third and fourth heat treatments are performed in an inert gas atmosphere of nitrogen, helium, argon, etc., and a manufacturing method of a silicon carbide semiconductor device is provided achieving a normally OFF characteristic and lowered interface state density.