Patent ID: 7178127

Claim:
A method of modifying a photomask pattern, comprising: providing an input file in a format selected from the group consisting of GDSII and Oasis, wherein the input file specifies a target pattern for a layer of an integrated circuit device and wherein the target pattern includes a plurality of enclosed regions; storing a representation of the target pattern comprising a plurality of values, wherein each value corresponds to a respective position over an area of the target pattern; at least one of the values corresponds to a position within at least one of the enclosed regions of the target pattern; at least one of the values corresponds to a position outside of the enclosed regions of the target pattern; each value corresponding to a position within one of the enclosed regions of the target pattern is within a first range of values; and each value corresponding to a position within one of the enclosed regions of the target pattern is within a second range of values, wherein the first range of values and the second range of values are non-overlapping; determining a plurality of change values corresponding to each of the respective position over at least a portion of the area of the target pattern; modifying the representation of the target pattern based on the plurality of change values; and using the modified representation to provide an output file in a format selected from the group consisting of GDSII and Oasis, wherein the output file specifies a modified pattern different from the target pattern.