METHOD FOR FORMING RESIST PATTERNS AND METHOD FOR PRODUCING PATTEREND SUBSTRATES EMPLOYING THE RESIST PATTERNS

Residual film etching steps for etching a resist film, onto which a pattern of protrusions and recesses has been formed, include: a first etching step employing a first etching gas including a sedimentary gas that generates sediment during etching, to etch the resist film such that the sediment is deposited on the sidewalls of protrusions of a resist pattern while residual film is etched. In the steps following the first etching step, the resist film is etched such that the widths of the protrusions including the deposited sediment become a desired width greater than or equal to the widths of the protrusions prior to residual film etching. Thereby, it becomes possible for the widths of protrusions of resist patterns following residual film etching to become desired widths greater than or equal to the widths of the protrusions of the resist patterns prior to residual film etching when forming resist patterns.