Scanner performance predictor and optimizer in further low k1 lithography

Due to the importance of errors in lithography scanners, masks, and computational lithography in low-k1 lithography, application software is used to simultaneously reduce them. We have developed "Masters" application software, which is all-inclusive term of critical dimension uniformity (CDU), optical proximity effect (OPE), overlay (OVL), lens control (LNS), tool maintenance (MNT) and source optimization for wide process window (SO), for compensation of the issues on imaging and overlay. In this paper, we describe the more accurate and comprehensive solution of OPE-Master, LNS-Master and SO-Master with functions of analysis, prediction and optimization. Since OPE-Master employed a rigorous simulation, a root cause of error in OPE matching was found out. From the analysis, we had developed an additional knob and evaluated a proof-of-concept for the improvement. Influence of thermal issues on projection optics is evaluated with a heating prediction, and an optimization with scanner knobs on an optimized source taken into account mask 3D effect for obtaining usable process window. Furthermore, we discuss a possibility of correction for reticle expansion by heating comparing calculation and measurement.