High-Precision Contouring from SEM Image in 32-nm Lithography and Beyond

The new contouring technology that we developed executes secondary pattern matching based on the information from lines of primary contour and design data. By the secondary pattern matching, rotation error and XY shift is eliminated to locate the contour at the correct position to design coordinates system. The developed method, in the next phase, can generate averaged contour of plural patterns from repeating patterns in a SEM image or from plural contours that are aligned accurately by the developed algorithm. When the developed contouring technology is compared with the conventional one, it minimizes contouring error and pattern roughness effect to the minimum and enables contouring that represents the contour across the wafer. The Contour that represents the contour across the wafer we name “Measurement Based Averaged Contour” or MBAC. When OPC rule is generated using MBAC, OPC with high robustness is expected to be generated.