Patent ID: 7645658

Claim:
A method of manufacturing a silicon carbide semiconductor device having a metal-oxide semiconductor structure, the method comprising: preparing a substrate made of silicon carbide; forming a channel region made of silicon carbide on the substrate, wherein the channel region provides an electric current passage; forming a first impurity region on the substrate on an upstream side of the electric current passage; forming a second impurity region on the substrate on a downstream side of the electric current passage; forming a gate insulation layer on a surface of the channel region; forming a gate electrode on the gate insulation layer to form a semiconductor element; forming a film on the semiconductor element to provide a material of an interlayer insulation layer; performing a reflow process at a temperature about 700° C. or over in an wet atmosphere so that the interlayer insulation layer is formed from the film; decreasing the temperature at about 700° C. or lower after performing the reflow process; changing the wet atmosphere to an inert gas atmosphere after the temperature is decreased at about 700° C. or lower; and performing a dehydration process in the inert gas atmosphere so that the interlayer insulation layer is dehydrated, wherein: the channel region provides a channel of the semiconductor element; and the channel is controlled by controlling a voltage applied to the gate electrode so that an electric current flowing between the first impurity region and the second impurity region is controlled.