PRE-ALIGNMENT MARKING AND INSPECTION TO IMPROVE MASK SUBSTRATE DEFECT TOLERANCE

摘要

A method includes determining defect types and defect locations on a mask blank and storing the defect types and the defect locations on the mask blank. The method further includes generating at least one alignment mark on the mask blank and selecting a mask pattern for the mask blank based on the defect types and the defect locations. Additionally, the method includes determining a positioning of the mask pattern on the mask blank, aligning a mask pattern generator with the mask blank in accordance with the positioning using the at least one alignment mark and forming the mask pattern in the mask blank using the mask pattern generator.