Patent ID: 8778201

Claim:
A method for forming a pattern comprising: forming a pattern transfer film on a substrate; forming a film made of a pattern forming material comprising a block copolymer or graft copolymer having two polymer chains whose ratio between dry etching rates is 1.3 or more on the pattern transfer film; annealing the film to form a microphase-separated structure in the film; ion-etching the film to selectively remove a polymer phase from the microphase-separated structure formed in the film; etching the pattern transfer film by using remaining another polymer phase as a mask, thereby transferring the pattern of the microphase-separated structure to the pattern transfer film; and etching the substrate by using the pattern transfer film as a mask in which the microphase-separated structure is transferred, thereby transferring the pattern of the microphase-separated structure to the substrate, wherein the ion-etching is performed with Ar, O 2 , CF 4 , H 2 , C 2 F 6 , CHF 3 , CH 2 F 2 , CF 3 Br, N 2 , NF 3 , Cl 2 , CCl 4 , HBr, or SF 6 .