US Patent 7348106 Method for repairing a phase shift mask

A method is disclosed for repairing an attenuated phase shift mask. The mask initially has a mask substrate coated with a predetermined shift layer material, a mask pattern layer, and an energy beam resist layer sequentially. After forming a predetermined mask pattern in the mask pattern layer through an energy beam resist layer, the mask is inspected for detecting at least one missing pattern in the mask pattern layer. The predetermined mask pattern is repaired in a predetermined defect area for correcting the missing pattern. After the missing pattern is reformed. The predetermined mask pattern is transferred in the shift layer material.