STATISTICAL OVERLAY ERROR PREDICTION FOR FEED FORWARD AND FEEDBACK CORRECTION OF OVERLAY ERRORS ROOT CAUSE ANALYSIS AND PROCESS CONTROL

摘要

Methods for collecting data and predicting overlay errors using patterned wafer geometry data and other related information, training, validating, and deploying the statistical model include selecting a training wafer set, measuring at a plurality of lithography steps, Applying a plurality of prediction models to the training wafer geometry difference, and comparing the prediction overlay with a measurement overlay of the training wafer set. The most accurate predictive model is identified and the results are fed forward to a lithographic scanner tool that can correct the effects and reduce overlay errors during wafer scanning and exposure processing.