Development of a novel closed EUV pellicle for EUVL manufacturing

As for the EUV pellicle, closed pellicle structure with the filters which has fundamentally no penetration path of particles is needed to keep the clean reliability level of photomask equivalent to the current photolithography. We proposed a novel closed EUV pellicle equipped with filters which has not only the particle intrusion prevention but also the ventilation performance. Full-size closed EUV pellicle was fabricated by forming the vent holes in the Si border part and putting the wide filters on the top side of Si border. As the result, we experimentally confirmed the suppression of the membrane deflection under the practical pumping down condition.