Patent ID: 7797656

Claim:
A method of checking and correcting a mask pattern, comprising: inputting a mask pattern, wherein the mask pattern comprises at least a segment comprising a plurality edges; inputting a process rule; selecting a target edge from the plurality of edges in accordance with an angle-related orientation model for sorting the edges of the mask pattern into multiple different pattern situations, wherein two ends of the target edge are an ahead point and a behind point, an ahead direction extending along a periphery of the target edge from the ahead point, a behind direction linking to the behind point along the periphery of the target edge, and the ahead point and the behind point each further comprise at least a checking direction; wherein the ahead direction is parallel to one of the directions in the orientation model and the behind direction is parallel to one of the directions in the orientation model; identifying an interacting edge in proximity to the target edge from the mask pattern along the checking directions; performing, by using a computer, a process rule check in accordance to the process rule to provide a correcting value in order to adjusting the relative position of the target edge and the interacting edge; performing a first correction to provide a first bias to the target edge; and performing a second correction to provide a second bias to the interacting edge, wherein a sum of the first bias and the second bias equals the correcting value to output a corrected mask pattern.