Photocurable positive photoresist-comprising copolymers having pendant alkoxy ethyl moieties

Abstract

A series of copolymers based on methacrylic acid (MAA), methyl methacrylate (MMA), n-butyl methacrylate (BM), and bornyl methacrylate (BMA) with various feed molar ratios were synthesized. To introduce the protecting alkoxy ethyl moieties onto copolymers, the pendant carboxyl groups were further reacted with alkyl vinyl ether. The pendant alkoxy ethyl groups on copolymers could be deprotected by acid catalyst. Characterization of positive-tone photoresist-comprising copolymers having pendant alkoxy ethyl groups was carried out. Effects of alicyclic bornyl groups on the sensitivity and thermal properties of copolymers were investigated. It was found that the existence of bornyl groups in polymer might interfere with the hydrogen bonding produced by pendant carboxyl groups, leading to the decrease of thermal resistance. Acid-catalyzed dehydration crosslinking of pendant carboxyl groups of copolymers was also investigated. The exposure characteristic curves and the lithographic evaluation of the positive-tone photoresist were all investigated. Effects of alicyclic bornyl groups on the plasma etching resist of copolymers were also evaluated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 889–897, 2002