DISSOLUTION STUDY OF A NOVOLAK-BASED PHOTORESIST BASED ON A DEVELOPERDIFFUSION-MODEL

Dissolution characteristics of a positive chemically amplified photore sist, AZ-PF514 from Hoechst Celanese, have been studied. Development r ate monitor data for different developer concentrations are analyzed. The experimental dissolution rates of the X-ray-exposed photoresist ar e examined in view of the dissolution model proposed earlier by Reiser . Parameters of Reiser's model associated with the diffusion of an aqu eous base through a thin penetration layer and solubility of a phenola te complex in an aqueous base solution are derived for different X-ray exposure conditions. Reiser's dissolution model was used to simulate the developed photoresist pattern profile. An example of 0.25 mu m pat tern development simulation using a dose-dependent coefficient for dif fusion of a developer base into polymer is demonstrated.