Silylation Processes for 193-nm Lithography Using Acid-Catalyzed Resists

摘要

A systematic study of acid-catalyzed resist formulations was used to investigatethe mechanism for resist behavior in a 193-nm silylation process. Sensitivities for these resists are higher than that of base resins even when processed without their normal post-exposure bake. To investigate this, resist formulations with different combinations of the constituent components of typical acid-catalyzed resists were evaluated. Both liquid-phase and vapor-phase silylation processes were employed and a range of post-exposure bake temperatures between 100 and 140 deg C was used. The improved sensitivity for the acid-catalyzed resists is not due to heating during the vapor-phase silylation process or during the laser pulse. Instead, evidence was found for a direct crosslinking reaction between phenolic resin groups in the presence of acid without a melamine additive.