Patent ID: 8551691
Filing Date: 2013-10-08
Classification: G03F,H01L

Abstract:
1. A method of forming a mask pattern comprising: forming a first resist film on a film to be etched formed on a substrate; forming opening portions on the first resist film at a predetermined pitch; forming a first film on the first resist film so as to cover sidewalls of the first opening portions; forming a second resist film on the first film; forming second opening portions which are alternately arranged with the first opening portions on the second resist film; forming a second film on the second resist film so as to cover sidewalls of the second opening portions; removing a part of the second film so that the second film is left as first sidewall portions covering the sidewalls of the second opening portions; removing a part of the first resist film using the first sidewall portions as a mask to form third opening portions corresponding to the second opening portions on the first resist film; and removing a part of the first film while leaving the first film to cover the sidewalls of the first opening portions as second sidewall portions so as to form fourth opening portions in which the sidewalls of the first opening portions are covered by the second sidewall portions.