Patent ID: 7233887

Claim:
A method of photomask design layout comprising the steps of: transforming photomask dimensional design data into spatial frequency data using a frequency transforming operation; creating a process model for a low-pass filter where the process model correlates to photomask design geometry and lithographic imaging conditions; filtering frequency representation of the dimensional design data with the low-pass filter across features having a variable proximity to one another ranging from a dense proximity to a semi-isolated proximity; transforming the filtered frequency representation of the dimensional design data into filtered dimensional design data using an inverse frequency transforming operation; creating a dose equalization function corresponding to a normalized reciprocal map of the filtered dimensional design data; creating a threshold leveled photomask design with equalized isofocal intensity values for filtered dimensional design data using the dose equalization function; generating a proximity corrected photomask comprising proximity mask corrections using the photomask design with equalized isofocal intensity values; using the proximity corrected photomask in a lithography exposure system to produce proximity corrected patterns on a imaged substrate.