Time-Constrained Single-Armed Cluster Tools Requiring Chamber Cleaning Operations: Schedulability Analysis and Scheduling Approaches

In semiconductor manufacturing, chamber cleaning operations (CCOs) are performed from time to time to clear particles and chemical gases that remain in the processing chambers of cluster tools (CTs) to ensure wafer quality. For single-armed CTs with just one CCO that could be completed in one system cycle time, researchers have proposed several scheduling approaches. In practice, more than one CCO may be required concurrently, thus failing the existing ones under such cases. Furthermore, the duration of a cleaning operation may be larger than one system cycle time, which highly complicates the scheduling of such tools. This work addresses this challenge by proposing several scheduling approaches and algorithms for single-armed CTs with several CCOs, each of which exceeds the duration of one system cycle. Suggestions are given for engineers in semiconductor fabrication plants to take the most suitable scheduling approach and algorithm for enhancing the productivity of CTs given their specific scenarios. Finally, two illustrative examples are provided to showcase the power of the proposed concepts and techniques.