Weighting evaluation for improving OPC model quality by using advanced SEM-contours from wafer and mask

OPC modeling has been complex procedure in 28nm node, and it becomes difficult to obtain enough OPC modeling accuracy if calibration is done by using only CD value. Therefore it becomes essential to take pattern shape variation into consideration especially in 2D pattern calibration. Thus utilizing SEM-contour has become important technology. In SPIE advanced lithograpy 2010 [3], Contour-based OPC-modeling by using Advanced SEM-contour which is combined with Fine SEM Edge, alignment and averaging technologies was examined, and model quality was significantly improved. Also, in SPIE advanced lithography 2011, an advanced hybrid OPC modeling which uses 1D CD measurements by CD-SEM and 2D contours created by the advanced SEM-contouring technology and panoramic Mask SEM-contour showed high predictability for both 1D and 2D, even though the relationship between 1D and 2D calibration has trade-off. In this study, weighing function of Calibre ContourCal, a product of Mentor Graphics, was evaluated using the OPC data set same as that used in SPIE2011. The weighting can be set for 1D structure and 2D structure separately. In this paper, the quality of OPC model by applying different weighting is discussed.