MODELING, ANALYSIS, SIMULATION, SCHEDULING, AND CONTROL OF SEMICONDUCTOR MANUFACTURING SYSTEMS - A PETRI-NET APPROACH

This paper presents a Petri net approach to modeling, analysis, simula tion, scheduling, and control of semiconductor manufacturing systems. These systems can be characterized as discrete event systems that exhi bit sequential, concurrent, and conflicting relations among the events and operations. Their evolution is dynamic over time, The system comp lexity is tremendous owing to the complex semiconductor manufacturing processes and test procedures. A formal approach such as Petri nets en ables one to describe such complex discrete event systems precisely an d thus allows one to perform both qualitative and quantitative analysi s, scheduling and discrete-event control of them. This paper also serv es as a tutorial paper. It briefly reviews applications of Petri nets in semiconductor manufacturing automation. It then introduces definiti ons and concepts of Petri nets. It proceeds with a discussion of basic Petri net modules in system modeling, a modeling method and a practic al system's modeling example. Next, the paper presents their propertie s and their implications in manufacturing systems, as well as their an alysis methods. Timed Petri nets are introduced for system simulation, performance evaluation, and scheduling purposes. An application-orien ted case study is presented. Finally, the paper concludes with the act ive research areas in applying Petri nets to design of semiconductor m anufacturing systems.