Patent ID: 9337327
Filing Date: 2016-05-10
CPC Classification: H01L

Claim Text:
1. A manufacturing method of a semiconductor device comprising the steps of: (a) providing a substrate of a first conductivity type containing silicon carbide; (b) forming a semiconductor layer of the first conductivity type containing silicon carbide and having a first region and a second region adjacent to each other along the upper surface thereof over the substrate; (c) forming a first semiconductor region of a second conductivity type different from the first conductivity type over the upper surface of the semiconductor layer in the first region and forming a second semiconductor region of the first conductivity type over the upper surface of the semiconductor layer in the second region; (d) after the step (c), sequentially forming a first insulating film and a first semiconductor film including a material having a larger oxidation rate than silicon carbide over the semiconductor layer; (e) exposing the upper surface of the first insulating film by opening the first semiconductor film in the first region; (f) exposing the upper surface of the first semiconductor region in the first region by opening the first insulating film exposed from the first semiconductor film by a wet etching method; (g) after the step (f), forming a gate insulating film over the semiconductor layer in the first region by oxidation treatment and forming a second insulating film containing a film formed by oxidizing the first semiconductor film and the first insulating film and having a film thickness larger than the gate insulating film by the oxidation treatment; and (h) embedding and forming a gate electrode between plural parts of the second insulating film opposing to each other with the first region interposed therebetween.