MASK PATTERN FORMING METHOD

摘要

PROBLEM TO BE SOLVED: To form a mask pattern of high dimensional precision by preventing the change of width of a mask pattern line after plasma dry etching to a resist pattern turning to an etching mask, in a forming method of a mask pattern for an EUV lithography. SOLUTION: Mask pattern material on a base substrate coated with a multilayer film, and reaction gas which is used when the mask pattern material is worked with plasma dry etching are so combined that at least one kind of reaction product formed when the plasma dry etching is performed becomes solid phase at a room temperature or a substrate temperature which is raised during the plasma dry etching.