A rigorous mathematical formulation to Automated Wet-Etch Station scheduling with multiple material-handling robots in Semiconductor Manufacturing Systems

摘要

Track systems have been increasingly utilized in many different stages in the Semiconductor Industry. Most of the manufacturing processes, particularly those executed in the wafer fabrication, require these transportation devices to perform the transfers of wafers lots through several process steps. Since these process steps only produce one lot at a time in a single bath, the number of transfer operations between consecutive baths increases drastically with the number of steps and lots in the system. Therefore, the problem to be tackled in this work aims at finding the efficient structure and operation strategy of a particular track system working in an Automated Wet-Etch Station (AWS). A rigorous mathematical formulation (MILP) for the simultaneous scheduling and design of the AWS is developed in order to minimize the residence time of wafer lots in the system, providing at the same time a better utilization of track's resources.