2009 Volume 22 Issue 1 Pages 25-29
A study of polymerization and some of the resulting properties of PAG-bound resist polymers based on a new triphenyl sulfonium fluoroalkyl sulfonate-containing methacrylate monomer is reported here. A low activation ester terpolymer containing this onium salt monomer was prepared and characterized. Our findings include the profound impact of residual monomer in the behavior of this material and the critical importance of polymer purification to remove unreacted ionic monomers in the preparation of polymer-bound PAGs. We have developed a polymer isolation process specifically tailored to remove unbound PAG so that the properties could be unambiguously investigated. And we report here the influence on properties of bound vs unbound PAG in this chemically amplified resist.