A polymer including a first repeating unit derived from a first monomer represented by formula (1); and a second repeating unit comprising an acid labile group, a hydroxyaryl group, a sulfonamide group, a fluoroalcohol group, or a combination thereof,




wherein, in formula (1), P is a polymerizable group comprising an ethylenically unsaturated carbon-carbon double bond; L1 is a single bond or a linking group; Ar is a substituted or unsubstituted C6-30 aromatic group or a substituted or unsubstituted C4-30 heteroaromatic group; X is O or S; A is a group selected from —O—, —S—, —S(O)—, —S(O)2—, —C(O)—, —C(S)—, or —N(Ra)—; Ra is hydrogen or a non-hydrogen substituent; and R1 and R2 are each as defined herein, wherein the first repeating unit and the second repeating unit are structurally different.