Method for manufacturing silicon carbide semiconductor device

摘要

A silicon carbide substrate is prepared which has a main surface covered with a silicon dioxide layer. In the silicon dioxide layer, an opening is formed by etching. In the opening, a residue resulting from the etching is on the silicon carbide substrate. The residue is removed by plasma etching in which only an inert gas is introduced. After removing the residue, under heating, a reactive gas is supplied to the silicon carbide substrate covered with the silicon dioxide layer having the opening formed therein. In this way, a trench is formed in the main surface of the silicon carbide substrate.

主权项

1. A method for manufacturing a silicon carbide semiconductor device, comprising the steps of:
preparing a silicon carbide substrate having a main surface covered with a silicon dioxide layer; forming a photoresist layer having a pattern on said silicon dioxide layer; forming an opening in said silicon dioxide layer through etching with said photoresist layer being used as a mask, so as to expose a portion of said main surface through said opening, a residue resulting from said etching being on said portion of said main surface exposed through said opening; removing said residue by plasma etching in which only an inert gas is introduced; after the step of removing said residue, forming a trench, which has a side wall surface, in said main surface of said silicon carbide substrate by supplying a reactive gas, under heating, to said silicon carbide substrate having said main surface covered with said silicon dioxide layer having said opening formed therein; forming a gate insulating film on said side wall surface of said trench; and forming a gate electrode on said gate insulating film.