Patent ID: 7871761

Claim:
A method for forming a pattern on a substrate by lithography, the method comprising at least steps of: forming a resist lower layer on a treatment portion of the substrate using a material comprising: a crosslinkable polymer; and a thermal acid generator that can generate an acid by heating at 100° C. or greater and is represented by the following general formula (1a): R 1 CF 2 SO 3 − (R 2 ) 4 N + (1a), wherein R 1 is a substituted or unsubstituted straight-chain, branched or cyclic C 1 to C 20 alkyl group, which may have —O—, —O—C(═O)—, —C(═O)—, —C(═O)—O—, a hydroxy group, a double bond or a C 6 to C 20 aryl group, and in which one or more hydrogen atoms may be substituted with a fluorine atom, but not all the hydrogen atoms are substituted with fluorine atoms; or a substituted or unsubstituted C 6 to C 20 aryl group in which one or more hydrogen atoms may be substituted with a fluorine atome, but not all the hydrogen atoms are substituted with fluorine atoms; and R 2 each independently represents a hydrogen atom; a substituted or unsubstituted straight-chain, branched or cyclic C 1 to C 10 alkyl group, alkenyl group, oxoalkyl group, or alkyl group having a hydroxy group or amino group; a substituted or unsubstituted C 6 to C 18 aryl group, aralkyl group or aryloxoalkyl group; or a group in which at least two of R 2 may bond mutually to form a ring together with N in the formula; forming a resist upper layer on the resist lower layer using a photoresist composition so as to obtain a multilayer resist film comprising at least two layers; exposing a pattern circuit region of the multilayer resist film to light; after the exposure, developing the multilayer resist film with a developer to form a resist pattern on the resist upper layer; and etching the resist lower layer and the treatment portion of the substrate using the resist upper layer having the resist pattern formed thereon as a mask so as to form a pattern on the substrate.