Method for repairing mask-blank defects using repair-zone compensation

摘要

A method for repairing mask-blank defects uses repair-zone compensation. Local disturbances are compensated over the post-defect-repair repair-zone by altering a portion of the absorber pattern on the surface of the mask blank. This enables the fabrication of defect-free (since repaired) X-ray Mo-Si multilayer mirrors. Repairing Mo-Si multilayer-film defects on mask blanks is a key for the commercial success of EUVL. It is known that particles are added to the Mo-Si multilayer film during the fabrication process. There is a large effort to reduce this contamination, but results are not sufficient, and defects continue to be a major mask yield limiter.