具有混合晶圆流的单臂组合设备建模及调度

Modeling and scheduling of single-armed cluster tools with mixed wafer flows

为有效提高组合设备利用水平与工作效率,研究在单臂组合设备上实现不同种类晶圆混合加工的问题。建立独立于具体晶圆流的单臂组合设备Petri网模型,该模型能准确描述不同晶圆流模式下系统的运行过程。基于拉式调度策略和周期调度的思想,推导出单臂组合设备在混合晶圆流下能形成稳定周期性加工的条件。然后依据约束条件建立系统的线性规划模型,获得稳态的周期调度。运用虚拟晶圆方法实现所得调度,并给出调度的甘特图。最后,以晶圆制造的数据作为算例验证了模型和调度的有效性。

For improving the efficiency of cluster tools availably, the issues for processing different types of wafers concurrently in single-armed cluster tools are studied. A Petri net model describing the process of the single-armed cluster tools precisely, which is independent of diverse wafer flow pattern, is developed. Some equations,which define that the single-armed cluster tools is ca- pable of performing a steady and cyclic operation under mixed wafer flows, are derived based on backward and cyclic scheduling strategy. Furthermore,the linear programming model is established and a periodic steady-state schedule is obtained as well. The presented scheduling is executed by the means of virtual wafer and the Gantt chart of scheduling is provided. Finally, the validity and efficiency of the proposed model and scheduling is verified.