| 摘要 |
A method for repairing bump and divot defects in phase shifting masks is performed by first identifying the locations of defects. Then, whether the defect is in a phase shift well or non-phase shift area is determined. The mask is then coated with photoresist. The immediate area surrounding each defect to be repaired (depending upon whether the defect is in a phase shift well or non-phase shift area), is then exposed to ultraviolet light. Additional defects are then identified and corresponding areas of the resist exposed. The resist is then developed such that the defect areas are not covered by the resist. Then SOG (spin on glass) material is deposited in the defect areas. The thickness of the SOG material at the areas to be repaired is measured. The SOG material is then etched to the surface of the substrate, thereby repairing both bump and divot defects. The process is performed in two iterations in which defects in a first type of area (phase shift or non-phase shift) are repaired in the first iteration and the remaining defects are repaired in the second iteration. The process may be performed using an optical microscope with yellow and ultraviolet light filters and an adjustable field aperture.
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