Integrated Constraint Programming Scheduling Approach for Automated Wet-Etch Stations in Semiconductor Manufacturing

Abstract

This article addresses a challenging resource constrained flow shop scheduling problem from automated wet-etch stations (AWSs) in wafer fabrication of semiconductor manufacturing facilities by means of a constraint programming (CP) methodology. Wet etching in wafer fabrication is a difficult process considering the material handling limitations and mixed intermediate policies. The proposed integrated approach consists of both a CP model and an efficient search strategy in order to handle the different features of the process. The domain-specific search strategy significantly improves the computational performance, a key aspect given the high combinatorial complexity of the problem. The search strategy objective is to avoid losing time due to early bad choices in the exploration and to produce good quality solutions with low computational effort. The applicability of the proposed integrated CP methodology is successfully tested with several examples taken from the literature, featuring a different number of jobs and baths.