Real time process monitoring using diffraction-based overlay measurements from YieldStar

Real-time process monitoring (RTPM) is a method for semiconductor manufacturing monitoring and tuning using a physical prediction model. It is a fast and nondestructive process excursion measurement method which takes inputs from diffraction-based overlay measurements from YieldStar. The prediction model is created by a physical model which receives standard manufacturing information as input. The prediction capability has been validated in a manufacturing environment experiment with thin film thickness prediction difference less than 3%.