Photo track defect control using multiple masking layer defect data

The defect monitoring strategy presented here has been developed for defectivity feedback for track and stepper issues typically seen in a high volume multi-device manufacturing facility. It combines data streams from multiple masking layers and product mixes improving the signal to noise ratio (S/N) of the defectivity signal utilizing an AMD/Spansion developed statistical control system known as ASPECT. True defect driven failures at the current layer, faster feedback loops, and a more comprehensive look at potential problems within the photo lithography area are the results of this integrated monitor process control strategy.