A photoresist underlayer composition, comprising a polymer comprising a repeating unit of formula (1):




wherein Ar is a monocyclic or polycyclic C5-60 aromatic group, wherein the aromatic group comprises one or more aromatic ring heteroatoms, a substituent group comprising a heteroatom, or a combination thereof; R1 is hydrogen, substituted or unsubstituted C1-30 alkyl, substituted or unsubstituted C1-30 heteroalkyl, substituted or unsubstituted C3-30 cycloalkyl, substituted or unsubstituted C2-30 heterocycloalkyl, substituted or unsubstituted C2-30 alkenyl, substituted or unsubstituted C2-30 alkynyl, substituted or unsubstituted C6-30 aryl, substituted or unsubstituted C7-30 arylalkyl, substituted or unsubstituted C7-30 alkylaryl, substituted or unsubstituted C3-30 heteroaryl, or substituted or unsubstituted C4-30 heteroarylalkyl; and R2 is substituted or unsubstituted C1-30 alkyl, substituted or unsubstituted C1-30 heteroalkyl, substituted or unsubstituted C3-30 cycloalkyl, substituted or unsubstituted C2-30 heterocycloalkyl, substituted or unsubstituted C2-30 alkenyl, substituted or unsubstituted C2-30 alkynyl, substituted or unsubstituted C6-30 aryl, substituted or unsubstituted C7-30 arylalkyl, substituted or unsubstituted C7-30 alkylaryl, substituted or unsubstituted C3-30 heteroaryl, or substituted or unsubstituted C4-30 heteroarylalkyl, wherein R1 and R2 can be optionally taken together to form a ring.