Dynamic feedback controller for optical proximity correction

A dynamic feedback controller for Optical Proximity Correction (OPC) in a random logic layout using ArF immersion Lithography is presented. The OPC convergence, characterized by edge placement error (EPE), is subjected to optimization using optical and resist effects described by calibrated models (Calibre® nmOPC simulation platform). By memorizing the EPE and Displacement of each fragment from the preceding OPC iteration, a dynamic feedback controller scheme is implemented to achieve OPC convergence in fewer iterations. The OPC feedback factor is calculated for each individual fragment taking care of the cross-MEEF (mask error enhancement factor) effects. Due to the very limited additional computational effort and memory consumption, the dynamic feedback controller reduces the overall run time of the OPC compared to a conventional constant feedback factor scheme. In this paper, the dynamic feedback factor algorithm and its implementation, as well as testing results for a random logic layout, are compared and discussed with respect to OPC convergence and performance.