Reactive dissolution kinetics of lithographic copolymers

A wide range of phenomenological nonlinear dissolution behaviors has often been noted for real resist systems but no comprehensive framework has yet been proposed that explains the underlying physical phenomena and connects them to resist composition. We present a taxonomy of dissolution processes in representative resist copolymers measured using quartz crystal microbalance frequency-resistance analysis and optical reflectance measurements. The underlying physical and chemical processes leading to the observed behaviors are identified using a detailed chemical kinetics implementation of the critical ionization model for resist polymer dissolution.