Method for manufacturing silicon carbide semiconductor device

摘要

On a substrate, a silicon carbide layer provided with a main surface is formed. A mask is formed to cover a portion of the main surface of the silicon carbide layer. The main surface of the silicon carbide layer on which the mask is formed is thermally etched using chlorine-based gas so as to provide the silicon carbide layer with a side surface inclined relative to the main surface. The step of thermally etching is performed in an atmosphere in which the chlorine-based gas has a partial pressure of 50% or smaller.

主权项

1. A method for manufacturing a silicon carbide semiconductor device, comprising the steps of:
forming a silicon carbide layer on a substrate, said silicon carbide layer being provided with a main surface; forming a mask covering a portion of said main surface of said silicon carbide layer; forming a recess by etching said silicon carbide layer by means of a reactive ion etching or an ion milling using said mask; and thermally etching a side surface of said recess using said mask and chlorine-based gas at a temperature of not less than 700 degrees Celsius and not more than 1200 degrees Celsius in an atmosphere with reduced pressure in which said chlorine-based gas has a partial pressure of 50% or less so as to incline said side surface of said recess relative to said main surface, wherein said atmosphere with reduced pressure has a pressure of not more than 1/10 of an atmospheric pressure.