Method of fabricating semiconductor device

Abstract

A method of fabricating a semiconductor device, the method including forming a buffer oxide layer in a first region and a second region of a semiconductor substrate; forming a plurality of first preliminary mask patterns on the buffer oxide layer in the first region; forming a plurality of second preliminary mask patterns between every two adjacent first preliminary mask patterns from among the plurality of first preliminary mask patterns, respectively; forming a plurality of first mask patterns and a plurality of second mask patterns by trimming the plurality of first preliminary mask patterns and the plurality of second preliminary mask patterns; forming a plurality of first active region mask patterns for exposing the semiconductor substrate; defining a plurality of active regions in the semiconductor substrate by forming a trench including a plurality of first trench spaces having same width as the first space and a plurality of second trench spaces under the second space in the first region; and forming a first liner layer on the semiconductor substrate having the trench therein such that the plurality of first trench spaces are completely filled with the first liner layer.