Estimating semiconductor yield from equipment particle measurements

The authors describe the application of yield models to define the relative contribution of equipment to particle limited yield and outline methods for developing a detailed yield model which includes process characteristics, equipment particle measurements, and product design characteristics. Collecting equipment particle per wafer pass (PWP) measurements using particle measurement systems and validating model results are also discussed. These methods are illustrated using published equipment particle and process flow information. It is noted that use of detailed yield models is not restricted to the newest technologies. Integrating equipment PWP measurements in existing manufacturing operations allows use of yield models for improving existing processes. Continuous improvement from particle reduction increases yields in all stages of product maturity. Thus, using PWP measurements and yield models to estimate semiconductor yield from equipment particle measurements can improve semiconductor manufacturing productivity