A general tool-based multi-product model for high-mixed production in semiconductor manufacturing
针对现代半导体制造中高混合生产导致传统工具基EWMA控制器不稳定的问题，提出一种通用多产品模型，通过精确估计噪声扰动来隔离不同产品的生产，避免不稳定，并通过理论、仿真和工业案例验证了其优越性。
Concerning the high-mixed nature in modern semiconductor manufacturing, the original ‘tool-based’ exponentially weighted moving average (EWMA) controller is proved to be unstable when the plant-model mismatches are diverse for different products, leading to large variations and lots of wastes. Hence, this paper proposes a general multi-product model for ‘tool-based’ EWMA control. The core of the model lies in the algorithm on how to estimate the noise disturbance accurately, i.e. the noise is considered as the sum of the following two parts: the estimated noise after the thread has been processed in the last cycle and the cumulative noise during the period when the thread is not on production between the two cycles. In this way, the production for a particular thread is isolated from that of others to avoid instability existing in the traditional tool-based EWMA control. Superiorities of the proposed model are demonstrated through theoretical analysis, simulation experiment and industrial case study.