Contour-based variability decomposition for stochastic band metrology

Driving down imaging-induced edge placement error (EPE) is a key enabler of semiconductor technology node scaling1-3. From the 5 nm node forward, stochastic edge placement error (SEPE) is predicted to become the biggest contributor to total edge placement error. Many previous studies have established that LER, LCDU, and similar variability measurements require corrections for metrology artifacts and noise as well as mask variability transfer to more accurately represent wafer-level stochastic variability. In this presentation, we will discuss SEPE band behavior based on a methodology that allows local extraction of SEPE from total measured local variability (LEPU) in a generalized way along 2D contours.