Abstract
Recently, the exponential-weighted-moving-average (EWMA) statistic based controllers are popular in the semiconductor manufacturing. Due to the single-EWMA controller cannot compensate for the drifting process, a double-EWMA (dEWMA) controller was proposed to enhance the capability for controlling the wear-out process. Most related research about dEWMA controller has focused on developing tuning strategy or searching optimal gains in the static condition. Unfortunately, process environment is usually dynamic in a real manufacturing world. To achieve a better performance in the dynamic system, an adaptive dEWMA controller will be developed in this study. The proposed controller contains two modules, namely "Trigger Module"and "Dynamical Tuning Loop Module". Therefore, the developed controller can be viewed as an application on integrating statistical process control (SPC) and engineering process control (EPC). Simulation results showed that the proposed methodology can immediately adjust the controller gains in response to the disturbance parameter changes.