More robust Optical Proximity Correction (OPC) model is highly required with integrated circuits' CD (Critical
Dimension) being smaller. Generally a lot of wafer data of line-end features need to be collected for modeling.
Scanning Electron Microscope (SEM) images are sources that include vast 2D information. Adding SEM images
calibration into current model flow will be preferred. This paper presents a method using Mentor Graphics' Calibre
SEMcal and ContourCal to integrated SEM calibration into model flow. Firstly simulated contour is generated and
aligned with SEM image automatically. Secondly contour is edited by fixing the gap etc. CD measurement spots are
applied also to get a more accurate contour. Lastly the final contour is extracted and inputted to the model flow. EPE
will be calculated from SEM image contour. Thus a more stable and robust OPC model is generated. SEM calibration
can accommodate structures such as asymmetrical CDs, line end pullbacks and corner rounding etc and save a lot of
time on measuring line end wafer CD.