Establishing a cleaning process for attenuated phase-shift masks

摘要

Attenuating phase-shift masks are necessary for technology node development and are rapidly emerging as an enabling manufacturing technique. Production fabs need reliable mask cleaning and repelliclization service with fast turnaround time. Such service must provide mask detectivity density similar or better than that established for binary mask cleaning, and limit any effects to phase-shifting and transmission characteristics of the mask to within acceptably small tolerances. This paper will describe the steps taken to specify, establish, characterize and qualify suitable cleaning processes for i-line and DUV attenuated phase-shift masks to enable commercial cleaning and repelliclization.