Patent attributes
A method and system of optimizing the illumination of a mask in a photolithography process. A specific, preferred method includes the steps of: loading minimum design rules of a layout, loading exposure latitude constraints, loading mask error constraints, loading initial illumination conditions, simulating current illumination conditions, obtaining dose-to-print threshold from the minimum design rules (i.e., lines-and-space feature), applying OPC on the layout using the dose-to-print threshold, calculating DOF using the exposure latitude and mask error constraints, changing the illumination conditions in order to attempt to maximize common DOF with the exposure latitude and mask error constraints, and continuing the process until maximum common DOF is obtained.
