Method of forming pattern in photoresist layer includes forming photoresist layer over substrate, selectively exposing photoresist layer to actinic radiation forming latent pattern. Latent pattern is developed by applying developer to form pattern. Photoresist layer includes photoresist composition including polymer:




A1, A2, L are direct bond, C4-C30 aromatic, C4-C30 alkyl, C4-C30 cycloalkyl, C4-C30 hydroxylalkyl, C4-C30 alkoxy, C4-C30 alkoxyl alkyl, C4-C30 acetyl, C4-C30 acetylalkyl, C4-C30 alkyl carboxyl, C4-C30 cycloalkyl carboxyl, C4-C30 hydrocarbon ring, C4-C30 heterocyclic, —COO—, A1 and A2 are not both direct bonds, and are unsubstituted or substituted with a halogen, carbonyl, or hydroxyl; A3 is C6-C14 aromatic, wherein A3 is unsubstituted or substituted with halogen, carbonyl, or hydroxyl; R1 is acid labile group; Ra, Rb are H or C1-C3 alkyl; Rf is direct bond or C1-C5 fluorocarbon; PAG is photoacid generator; 0≤x/(x+y+z)≤1, 0≤y/(x+y+z)≤1, and 0≤z/(x+y+z)≤1.