A major factor in the substantial improvement in the performance and environmental stability of DUV chemical amplified resists involved a change in the chemistry of the protecting group. A divergence of resist design has recently occurred, leading to two completely different resist classes, each with its promises and problems. These new resists (once again based on hydroxystyrene copolymers and terpolymers) can be grouped by activation energy. In this paper the authors will attempt to answer these questions and perhaps highlight areas of additional concern. Results from our investigations of two photoresists of either high or low activation energy system will be presented. Critical parameters such as overall process windows for sub-200nm lithography variation with FEB temperature (linewidth/degrees C), FEB delay, line slimming, etch rates and bottle stability will be discussed.