An effective methodology of filter, measure, and align SEM image in model calibration

In the OPC development process, the following three problems can delay the entire model process. The first one is that experienced engineers usually need spend a lot of time to filter SEM image for model fitting. The second is that some SEM images CD can’t be measured in first measurement, and it is usually necessary to adjust the measurement recipe for second measurement to obtain the wafer CD value. The third one is that when model fitting is finished, engineers need to align SEM image to simulation contour to verify the model results, it takes a lot of time and has accuracy error. These problems can be solved by the SiV (Silicon Verification) tool.