Optimality Analysis of Single-Armed Robotized Manufacturing Tools for Concurrent Processing of Multiple Job Types

This study addresses the scheduling challenges in robotized manufacturing systems that enable concurrent processing of multiple product types, with emphasis on cluster tool environments used in semiconductor wafer fabrication. Concurrent processing increases scheduling complexity, as multiple wafer types compete for shared resources within the tool. This research examines the optimality of employing existing robot sequencing rules for single-armed cluster tools under concurrent processing conditions, focusing on how the cycle plan, which defines the wafer input sequence and governs chamber sharing across different wafer types, affects workload balance and overall tool productivity. The analytical results indicate how the cycle plan, the number of wafer types, and the chamber configuration should be structured to achieve balanced workloads across parallel resources, leading to the minimum tool cycle time. That is, the proposed framework provides practical guidelines for early-stage production planning decisions, including determining the tool configuration, selecting the wafer lot assignment, and formulating the cycle plan. The results contribute to improving scheduling efficiency and enhancing concurrent wafer processing in semiconductor manufacturing.