Biphenyl derivatives , resist undercoat material , resist underlayer film forming method and pattern forming method

摘要

A biphenyl derivative having formula (1) is provided wherein Ar1 and Ar2 denote a benzene or naphthalene ring, and x and z each are 0 or 1. A material comprising the biphenyl derivative or a polymer comprising recurring units of the biphenyl derivative is spin coated and heat treated to form a resist bottom layer having improved properties, optimum values of n and k, step coverage, etch resistance, heat resistance, solvent resistance, and minimized outgassing.