An 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; X is C or O; R1, R2; Ra and Rb are as provided herein; optionally, R1 and R2 can be taken together form a 5- to 7-membered ring; optionally, one of R11 to R13 can be taken together with R1 to form a 5- to 7-membered ring; wherein Ra and Rb optionally may be taken together to form a 5- to 7-membered ring; wherein one of Ra or Rb optionally may be taken together with R2 to form a 5- to 7-membered ring; and when X is O, Ra and Rb are absent.