Process Improvement of Wafer Measurement in the Semiconductor Industry

This project is to explore the use of Statistical Process Control (SPC), in particular the Exponentially Weighted Moving Average (EWMA), to ensure continues improvement in a chemical process. Particular interest in this study is to see how well analytical machines would measure the wafer thickness. EWMA requires that all past information is gathered with more weight given to the most recent data. In conclusion, the data under study reveals that EWMA is an effective way in controlling and detecting whether or not the moving target operates within the process limit and thus, confirm the reliability of the measurements by the machines