Subresolution features to homogenize heating density variations on the lithographic mask and wafer

摘要

In typical reticle designs used to pattern imaging radiation in optical lithography, feature density varies across a reticle. During exposure, these variations induce corresponding variations in heating density, temperature on the reticle and temperature on the wafer. These variations, in turn, cause variations in overlay. Some of these overlay variations are uncorrectable by many lithographic scanners.