Patent ID: 6448139
Filing Date: 2002-09-10
Classification: H01L

Abstract:
A manufacturing method of a semiconductor device comprising:depositing a mask member for forming a trench on a semiconductor substrate; patterning the mask member to form an opening portion therein; forming the trench in a depth direction of the semiconductor substrate by anisotropic etching through the opening portion; removing a polymer formed by the anisotropic etching from the trench; modifying a shape of the trench through a wet process using a mixed solution containing hydrofluoric acid and nitric acid so that a damaged layer in the trench formed by the anisotropic etching is removed; forming a thermal oxidation film on an inner surface of the trench by a thermal oxidizing treatment; removing the thermal oxidation film; removing the mask member from the semiconductor substrate; and forming an insulation film inside the trench.