半导体制造中多组合设备的Petri网建模及死锁分析

Petri net modeling and deadlock analysis of multicluster tools in semiconductor manufacturing

在半导体晶圆加工中必须保证组合设备运行时不存在死锁,为此,建立了多组合设备的模型并研究了无死锁运行问题.首先介绍了多组合设备的结构特征,用面向资源Petri网对它的结构建模;然后,在模型中引入了着色令牌和受控变迁,能很好地描述多组合设备加工晶圆的过程.此模型结构紧凑简洁,能分析加工过程中的稳态、初始暂态和趋停暂态阶段;同时分析了初始暂态阶段如何过渡到稳态阶段.最后,分析了模型的活性等动态行为,提出了避免死锁的控制策略.结果表明如果应用控制策略,多组合设备系统能无死锁运行,有助于对多组合设备进行调度.

Deadlock-freedom is essential for the operation of a cluster tool in semiconductor wafer manufacturing.This paper conducts a study of modeling multicluster tools and analysis of avoiding deadlock.After presenting the structural characteristics of multicluster tools,a resource-oriented Petri net（ROPN） model is developed for the architecture of multicluster tools.Then,by introducing colored tokens and controlled transitions into the model,wafer fabrication processes in multicluster tools can be well described.This model is compact and can describe not only the steady state process but also the initial and final transient processes.This model also shows how the production process is transferred from an initial state to the steady state.With this model,dynamical behavior,including liveness,is analyzed.Based on the analysis,a deadlock avoidance policy is proposed.It is shown that the system is deadlock-free if the control policy is applied.Thus,this model is helpful to schedule a multicluster tool system.