Search for multi-stack EUV pellicle membrane for EUV non-Actinic mask inspection

Abstract

The extreme-ultraviolet (EUV) mask cannot be inspected by using actinic inspection system because there is no commercial EUV actinic mask inspection system available yet. Moreover, the EUV pellicle must be removed if the EUV mask is inspected by non-Actinic inspection system, so that a novel EUV pellicle membrane is required to inspect the EUV mask without EUV pellicle removal in the non-Actinic inspection system. We have attempted to find an optimum combination as the multi-stack EUV pellicle membrane which can obtain not only high EUV transmission but also high deep-ultraviolet (DUV) transmission. Graphite-and silicon nitride (SiNx)-based EUV pellicle membrane have a larger DUV intensity after passing through optics than those of silicon-based pellicle membranes. Based on these results, we believe that these multi-stack EUV pellicle membranes have high DUV transmission as well as EUV transmission and it would make better performance with respect to fidelity of through-pellicle inspection compared to well-known EUV pellicle membranes. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.