| abstract |
A photoresist composition comprising an acid generator and a resin which comprises one or more structural units (a1) derived from a monomer (a1) having an acid-liable group, all of monomers (a1) showing a distance of Hansen solubility parameters between the monomer (a1) and butyl acetate in the range of 3 to 5, the distance being calculated from formula (1): n R =(4×(δ d m −15.8) 2 +(δ p m −3.7) 2 +(δ h m −6.3) 2 ) 1/2 (1)n n in which δd m represents a dispersion parameter of a monomer, δp m represents a polarity parameter of a monomer, δh m represents a hydrogen bonding parameter of a monomer, and R represents a distance of Hansen solubility parameters, and at least one of the monomers (a1) showing a difference of R between the monomer (a1) and a compound in which an acid is removed from the monomer (a1) in the range of not less than 5. |