基于eM-Plant求解具有晶圆重入过程的单臂组合设备最优调度的仿真方法

摘要

在半导体组合设备的晶圆加工过程中,常常要求晶圆重入,原子层沉积加工(ALD)就是典型的晶圆加工过程.对这样的系统实施调度是一个挑战性的问题.研究单臂组合设备的调度问题,目的在于求解ALD重入过程的最优调度.建立了系统的Petri网模型,利用该模型,可以通过比较非常有限的若干调度的生产节拍而得到其重入过程的最优调度.基于所建立的Petri网模型,开发出了基于eM-P1ant的仿真系统,可以有效地获得给定调度的生产节拍.给定系统的参数可以有效地求得重入过程的最优调度.文中应用例子来说明所提出的方法的应用.%For some wafer fabrication processes in cluster tools, wafer revisiting is required. Atomic layer deposition ( ALD) is such a typical revisiting process. It is a challenging problem to schedule a cluster tool for such a process. A study is conducted to schedule single-arm cluster tools to find an optimal schedule of the revisiting process of ALD. To do so, a Petri net model is developed to describe the behavior of the system. With this model, an optimal schedule can be obtained from very limited number of candidate schedules by just comparing the cycle time of these schedules. Based on the Petri net model, a simulation system is developed by using eM-Plant platform such that the cycle time of a schedule for the revisiting process can be efficiently obtained. In this way, given the parameters of the system for the revisiting process, an optimal schedule can be efficiently found. Illustrative examples are given to show the application of the proposed method.