Non-cyclic scheduling of dual-armed cluster tools for bi-objective minimization of wafer residence time and makespan

Abstract

Dual-armed cluster tools are widely used for semiconductor manufacturing. The system consists of several loadlock modules, processing modules, and material handling robots for transferring wafers between them. Most of the conventional works focused on the scheduling cluster tools for the minimization of makespan. It is also important to minimize the residence time in the process module in order to prevent the deterioration of the quality of the wafer surface. Also, cluster tools have to avoid deadlock situations which may lead to excessive loss for wafer fabrication system. In this paper, we propose an efficient scheduling method for deadlock avoidance strategy and the bi-objective of the minimization of makespan and wafer residence time.