Patent ID: 7907770

Claim:
A method for inspecting a photomask, applicable for a photomask having a pattern region and a blank region, the method comprising: providing a wafer for performing a photolithography process by the photomask, wherein the wafer has a plurality of exposure regions, each exposure region has a component pattern region, each component pattern region is surrounded by a scribe line region, each component pattern region corresponds to the pattern region of the photomask, and the scribe line region corresponds to the blank region of the photomask; dividing the scribe line region into a plurality of virtual pattern regions; and performing an overlap comparison step on the virtual pattern regions one by one, wherein when at least one of the virtual pattern regions incompletely overlaps the other virtual pattern regions, a part of the blank region on the photomask corresponding to the incompletely-overlapping virtual pattern region is defined as a haze.