Method of manufacturing semiconductor device including trench-forming process

Abstract

In a manufacturing method of a semiconductor device, a trench is formed in a semiconductor substrate by an anisotropic dry etching so as to have an aspect ratio greater than or equal to 10, and a damaged layer that is generated in a wall and a bottom of the trench due to the anisotropic dry etching is removed by an isotropic dry etching. The isotropic dry etching is performed with a first gas including carbon and fluorine and a second gas including oxygen. A temperature of the semiconductor substrate is controlled so that the damaged layer is removed from a whole surface of the wall and the bottom in the isotropic dry etching.

Dependencies are inferred from the claim text.