基于Markov过程的集束型设备预防维护策略

为了更好地保障集束型晶圆制造设备运行的可靠性,同时考虑维护的经济性,建立了基于Markov过程的预防性维护策略.根据集束型设备的特点,采用大修和小修相结合的预防性维护方式,同时考虑随机失效和退化失效两种失效形式,建立了状态转移模型.依据Markov理论求得设备各状态的稳态概率及状态转移概率.再根据Markov决策理论及策略迭代算法求得最佳维护策略.实验结果表明,所提出的预防性维护策略有效可行.

Preventive Maintenance Policy of Cluster Tools Based on Markov Process

Abstract： In order to ensure the reliability of cluster tools in semiconductor wafer fabrications, a Markov process based preventive maintenance policy was presented considering the economical efficiency. First, a state transfer model was established by applying the method of combining major maintenance and minimal maintenance, taking into account the random failure and degradation failure modes. Then, the steady state probability for each state and transition probabilities among states were calculated based on the Markov theory. After that, the optimal maintenance policy was obtained through the policy iteration algorithm and the Markov decision theory. Finally，numerous experiments were conducted. The results indicate that the proposed preventive maintenance policy is effective and feasible.