Advancement of Fast EUV Lithography Modeling/Simulations and Applications on Evaluating Different Repair Options to EUV Mask Multilayer Defect

摘要

EUV mask consists of an absorber layer and about 40-50 bi-layers of alternating molybdenum and silicon. Due to the high profile of the absorber layer relative to wavelength, and the non-telecentric nature of EUV optics, masks 3D- and shadowing-effects are important and must be taken into consideration. The presence of ML defect adds further challenges to EUV simulation. The goal of our simulator is to build an empirical model specially tailored to capture such effects by resurrect thin mask spectrum to match the results with rigorous simulation within the pupil of interests. We will first present the mechanisms we used followed by accuracy comparison of our EUV mask model. We will evaluate the effectiveness of different repair options for ML defect through simulation and their impact to process window.