| 摘要 |
PROBLEM TO BE SOLVED: To prevent a surface of an SiC substrate from immersion of metal ions and the occurrence of surface level difference caused by etching for an opening when a silicon oxide film is opened by etching for forming an ion implantation mask for a selective impurity implantation region on the SiC substrate.SOLUTION: When etching conditions of an opening 16 for impurity implantation on a surface of an SiC substrate 11 are represented by a rate selectivity Sa of an upper layer film 13/lower layer film 12, an etching rate Ra of the upper layer film 13, a thickness L1 of the lower layer film 12, and an overtime etching time Ta of the upper layer film 13, and conditions when the upper layer film is removed after the impurity implantation are an etching rate selectivity Sb of the upper layer film/lower layer film, an etching rate Rb of the upper layer film and an etching time Tb, the following inequality is satisfied: L1>(Ra×Ta/Sa)+(Rb×Tb/Sb). |
