Lithography system and lithography method for improving image contrast

摘要

Systems and methods are disclosed herein for enhancing lithography printability, and in particular, for enhancing image contrast. An exemplary method includes receiving an integrated circuit (IC) design layout and generating an exposure map based on the IC design layout. The IC design layout includes a target pattern to be formed on a workpiece, and the exposure map includes an exposure grid divided into dark pixels and bright pixels that combine to form the target pattern. The method further includes adjusting the exposure map to increase exposure dosage at edges of the target pattern. In some implementations, the adjusting includes locating an edge portion of the target pattern in the exposure map, where the edge portion has a corresponding bright pixel, and assigning exposure energy from at least one dark pixel to the corresponding bright pixel, thereby generating a modified exposure map.