| abstract |
A disclosed method of forming a mask pattern includes forming a first resist film on a film to be etched, opening portions on the first resist film at a predetermined pitch, a first film on the first resist film so as to cover sidewalls of the first opening portions, a second resist film, second opening portions alternately arranged with the first opening portions on the second resist film, and a second film on the second resist film so as to cover sidewalls of the second opening portions, and removing a part of the second film so that the second film is left as first sidewall portions, a part of the first resist film using the first sidewall portions as a mask to form third opening portions, and a part of the first film while leaving the first film as second sidewall portions to form fourth opening portions. |