Preparation and Photo- and Thermal-Curing Properties of Copolymers Applied in Negative-Type Photoresists

摘要

A series of monomers was polymerized and used as polymer binders in negative-type photoresists. The thermal properties of the polymer binders and the mechanical properties of their patterns were then studied. We used two four-component polymer binders: one consisting of methacrylic acid, styrene, benzyl methacrylate, and glycidal methacrylate, and another consisting of methacrylic acid, styrene, isobornyl methacrylate, and phenylmaleimide. Diallyl monoglycidyl isocyanurate (DA-MGIC) or monoallyl diglycidyl isocyanurate (MA-DGIC) was then reacted with the formed polymer binder to create a novel polymer binder with photo- and thermal-curing properties. The results showed that the thermal decomposition temperature (T_d) of the polymer binders increased when the DA-MGIC or MA-DGIC monomer was used in the binder; this was presumably due to the photo-curing, thermal-curing, and inter-penetration network characteristics of the polymer binders. Elastic recovery and compression of the patterns of the photoresist were measured using a nanoindenter. The results showed that the patterns exhibited excellent mechanical properties. The patterns were observed with a scanning electron microscope. The taper angle of the patterns became vertical due to the increased intensity of the inter-penetration network, which was revealed by the excellent inhibition of the pattern.