Simulating conveyor-based amhs layout configurations in small wafer lot manufacturing environments

Automated material handling systems (AMHS) using conveyors have been recently proposed as a technology option for next generation wafer fabrication facilities. This technology seems to provide an increasing capacity for moving and storing wafers in a continuous flow transport environment. The goal of this research is to design and test conveyor-based AMHS configurations, which include turntables and storage areas near the processing equipment. Simulation models were developed in AutoMod to determine the best conveyor layout, with emphasis in comparing centralized versus distributed storage systems. The AMHS factors under study comprise the number, location, and capacity of the storage areas. Simulation results show that the distributed storage approach provides improved performance; however, these systems require more capital investment than that needed for the centralized storage approach.