A CP-based Approach for Scheduling of Automated Wet-Etch Stations

This contribution addresses the resource-constrained flowshop scheduling problem of Automated Wet-etch Stations (AWSs) in wafer fabrication of semiconductor manufacturing facilities by means of a Constraint Programming (CP) methodology. The proposed integrated approach consists of both a CP model and an efficient search strategy. The former handles different features found in the complex automated wet-etching process, such as material handling and mixed intermediate storage policies. The domain-specific search strategy, significantly improves the computational performance, a key aspect given the high combinatorial complexity of the problem. The applicability of the proposed integrated CP methodology is successfully tested with four examples taken from the literature, featuring a different number of jobs and stages, with the outcome being better solutions with fewer computational resources.