Effect of Glass Transition Temperature on Compression and Elastic Properties of Poly(Meth)Acrylate Copolymer Thin Films and their Photoresist Patterns

Abstract

In order to study the effect of glass transition temperature (Tg) on the compression and elastic recovery properties of polymer, several poly(meth)acrylate copolymers having three or four segment units composed of methacrylic acid (MAA) and other vinyl monomers such as glycidyl methacrylate (GMA), styrene (STY), butyl acrylate (BAM), 2-hydroxyethyl methacrylate (HEMA), methyl methacrylate (MMA), benzyl methacrylate (BzMA), 2-ethylhexyl acrylate (EHA), octadecyl acrylate (ODA), ethyl acrylate (EAM), and lauryl methacrylate(LMA) were synthesized. The synthesized copolymers showed different glass transition temperatures depending on the component type. Thin films and micro patterns were prepared by photolithography process (spin coating/pre-baking/UV-exposure/KOH developing/post-baking) with prepared copolymer solution. The compression and recovery property of copolymer films and micro patterns were determined by nano indenter. As a result, copolymers with lower Tg especially MAA/GMA/STY, MAA/GMA/STY/BAM, and MAA/GMA/STY/HEMA copolymers showed higher compression and elastic recovery ratio.