Patent ID: 7879729

Claim:
A method of forming micro patterns of a semiconductor device, the method comprising: forming first etch mask patterns over a semiconductor substrate in which junction regions and isolation layers are alternately formed between drain select lines; forming an auxiliary film over the first etch mask patterns, wherein the auxiliary film is formed over sidewalls of the first etch mask patterns such that a space is defined between adjacent first etch mask patterns; forming a second etch mask film over an entire structure including the auxiliary film, wherein the first etch mask patterns and the second etch mask film comprise substantially the same material; forming a second photoresist pattern including an opening, wherein the opening is parallel to the drain select line and exposes a portion of the second etch mask film located between the drain select lines; etching the second etch mask film using the second photoresist pattern as an etching mask, wherein a second etch mask pattern is formed in the space defined between the adjacent first etch mask patterns; and removing the auxiliary film that is formed between the first and second etch mask patterns, wherein target patterns correspond to regions on the semiconductor substrate where the auxiliary film is removed.