a block copolymer film is formed on a substrate . then , the block copolymer film is annealed in an inert - gas atmosphere , for example , in a neon atmosphere . this places the outside of the block copolymer film in a nonpolar state , thereby strongly drawing , for example , a monomer unit having hydrophobic characteristics outside the block copolymer film to accelerate self - assembly . this results in an improvement in throughput in self - assembled pattern formation of the block copolymer film .