THE EFFECT OF DIFFUSION, REACTION ORDER, AND DEVELOPER SELECTIVITY ONTHE PERFORMANCE OF POSITIVE DUV RESISTS

Two different positive acid catalyzed DUV resists were investigated an d the differences in the reaction order, developer selectivity, and ma gnitude of acid diffusion were determined. The threshold acid theory o f image formation is used in conjunction with a reaction-diffusion mod el to determine the reaction order of the acid catalyzed deprotection reaction and the effect of acid diffusion in positive DUV resists. The acid diffusion coefficient for these positive DUV resists was also me asured. Finally, the developer selectivity of the different resists wa s determined and the effect of developer selectivity on resist perform ance was presented. It was also shown that this model does apply to po sitive acid catalyzed resists and thus can have general utility in des cribing acid catalyzed resist performance.