Efficient Scheduling of Residency-Time-Constrained Dual-Armed Cluster Tools With Condition-Based Chamber Cleaning Operations

Cleaning operations are required to clear particles and residual chemical gases in processing chambers of cluster tools in semiconductor manufacturing. To clean the chambers, condition-based chamber cleaning operations considering the actual state of chambers have been developed in practice. For single-armed cluster tools with such operations and wafer residency time constraints, the scheduling problem has been tackled. However, for dual-armed ones, this problem remains open and it is difficult to solve since their scheduling strategies are different from and more complex than single clusters’. To address this challenging problem, this work presents an efficient scheduling strategy to find the schedules that meet wafer residency time constraints and maximize their productivity. Two examples are given to show the effectiveness of the developed strategies.
Note to Practitioners
—Dual-armed cluster tools are extensively employed in semiconductor manufacturing processes. For residency-time-constrained dual-armed cluster tools with condition-based chamber cleaning operations, this work derives efficient scheduling strategies and algorithms for different cleaning cases. They can be used to realize feasible schedules that meet the wafer residency time constraints and restore a cluster tool to its steady-state as soon as possible. Hence, this work is significant and promising in helping semiconductor manufacturers enhance their fab’s throughput.