Applications of Taguchi and design of experiments methods in optimization of chemical mechanical polishing process parameters

This investigation applied the Taguchi method and designs of experiments (DOE) approach to optimize parameters for chemical mechanical polishing (CMP) processes in wafer manufacturing. Planning of experiments was based on a Taguchi orthogonal array table to determine an optimal setting. In this study, the material removal rate and non-uniformity of surface profiles were selected as the quality targets. This partial factorial experimental planning provided an efficient and systematic approach of determining an optimal parameter condition. Mathematical prediction models for the material removal rate and the non-uniformity of surface profiles were derived in terms of platen speeds, carrier speeds, back side pressure, slurry flow rates and head down forces by regression analysis. These parameters are found to be significant to both the removal rate and the non-uniformity of surface profiles for CMP processes.