Non-chemically amplified resists containing polyhedral oligomeric silsesquioxane for a bilayer resist system

Abstract

Silicon-containing photoresists are gaining increasing interest for bilayer resist systems due to their high oxygen plasma resistance. Bilayer resist materials based on a nonchemically amplified resist system were prepared by copolymerization of polyhedral oligomeric silsesquioxane (POSS)-containing monomer, 2( 2-diazo-3-oxobutyryloxy) ethyl methacrylate (DOBEMA), 2-hydroxyethyl methacrylate (HEMA) and styrene. A series of POSS-containing resists with varying POSS contents were synthesized to optimize the dry etch resistance and selectivity. Upon UV irradiation, the resist film produced high resolution negative tone patterns. A bilayer pattern can be fabricated readily by pattern transfer of a thin silicon-containing top layer into a thick crosslinked organic bottom layer by anisotropic O-2 reactive ion etching. Finally, potential of the POSS-containing resist as an etch mask has been established by successful transfer of patterns into a silicon substrate through dry etching in CF4/O-2 plasma. (C) 2016 Published by Elsevier Ltd