Copolymer approach to the design of sensitive deep UV resist systems with high thermal stability and dry etch resistance

As the trend toward the higher circuit density in microelectronic devices continues, there has been an increasing interest in lithographic technologies utilizing short wavelength radiations such as electron beam, X-ray, and deep UV. Deep UV lithography employing KrF excimer laser (248 nm) appears to emerge as a major technology for ULSI fabrication. In this paper, the authors report an alternative approach to the design of deep UV resist systems combining the desired properties, which involves copolymerization of methacrylic ester with styrenic comonomer and the use of the acid-catalyzed deprotection chemistry.