Patent ID: 7576009

Claim:
A method for forming a fine pattern of a semiconductor device, the method comprising: forming a stack film including a first mask film, a second mask film, and a third mask film over a semiconductor substrate having an underlying layer; forming a photoresist pattern over the third mask film; patterning the third mask film using the photoresist pattern as an etching barrier mask to form a third mask pattern; patterning the first and second mask films using the third mask pattern as an etching barrier mask to form a first and second mask patterns; side-etching the second mask pattern using the third mask pattern as an etching barrier mask; removing the third mask pattern; forming a spin-on-carbon layer over the second mask pattern so that an upper portion of the second mask pattern is exposed; performing an etching process to expose the underlying layer using the spin-on-carbon layer as an etching barrier mask so that the first mask pattern including an open part is formed; and removing the spin-on-carbon layer.