Photoresist undercoat-forming material and patterning process

摘要

A material comprising a specific bisphenol compound of formula (1) is useful in forming a photoresist undercoat wherein R¹ and R² are H, alkyl, aryl or alkenyl, R³ and R⁴ are H, alkyl, alkenyl, aryl, acetal, acyl or glycidyl, R⁵ and R⁶ are alkyl having a ring structure, or R⁵ and R⁶ bond together to form a ring. The undercoat-forming material has an extinction coefficient sufficient to provide an antireflective effect at a thickness of at least 200 nm, and a high etching resistance as demonstrated by slow etching rates with CF₄/CHF₃ and Cl₂/BCl₃ gases for substrate processing.