EWMA for run-to-run control with time-varying discount factor in high-mix process
基于变折扣因子EWMA的混合产品批间控制方法

Run-to-run(R2R) control is widely adopted in semiconductor manufacturing industries. Exponent weighted moving average(EWMA) is an important R2R algorithm. Discount factor is a major parameter of EWMA controller. Considering the high-mix characteristics of multi-product in practical manufacturing processes, we adopt the EWMA algorithm with time-varying discount factor to handle the slow convergence-rate in the product-switching phase. It improves the response speed while maintaining the stability of the process. The feasibility and advantages are demonstrated in simulations of practical processes.