Source imperfection impacts on optical proximity correction

This study explores the impact of illumination source defects on photolithography image fidelity when optical proximity correction (OPC) is used on the pattern. The objective is to gain understanding of how the nonlinearities produced in OPC impact the final pattern fidelity when source defects are introduced. Two variations of the study are executed: the first variation is the mask defect case where a defect is introduced in the pixilated source, an OPC model is created, then the corrected pattern is imaged with an ideal source. The second variation is the exposure defect case where the OPC correction is performed with an ideal source, then exposed with a defect in the manufacturing source. In both cases, defect size and location on the source are varied. The mask defect case demonstrates that to a limited size, OPC can overcome a source defect. The exposure defect case is less conclusive showing pattern shifts and background illumination impacting pattern through focus performance.