Method for forming fine pattern of semiconductor device

Abstract

A method for forming a fine pattern of a semiconductor device comprises the steps of: forming a first hard mask pattern having a width of Wand a thickness of Tover an underlying layer formed over a semiconductor substrate; forming a second hard mask film with a planar type over the resulting structure and planarizing the second hard mask s to expose the first hard mask pattern; removing the first hard mask pattern by a thickness Tfrom the top surface (0<T<T); performing a trimming process on the second hard mask film to form a second hard mask pattern having a slope side wall; performing a second trimming process on the second hard mask pattern to separate the second hard mask pattern from the first hard mask pattern and form a third hard mask pattern having a width of W; and patterning the underlying layer using the first hard mask pattern and the third hard mask pattern as etching masks.