Wafer Flow Time Control in Robotized Semiconductor Manufacturing Tools
研究了在机器人化集群工具中控制晶圆流时间的调度问题，发现通过调节晶圆装载水平可显著缩短流时间，但需权衡工具生产率，并提出了有效管理这一权衡的调度规则。
This research examines the problem of scheduling robotized cluster tools under the operational requirement of controlling <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">wafer flow time</i>. Recently, in wafer fabs, the wafer flow time is recognized as an important factor that impacts the quality level of semiconductor end-products. We first establish a theoretical basis for the analysis of the wafer flow time in cluster tools, and then we prove that the wafer flow time can be significantly reduced by regulating the wafer loading level inside the tool. It is also shown that there is a tradeoff between the wafer flow time and tool productivity, and thus the reduction of the wafer flow time can lead to an increased tool cycle time. To manage this tradeoff effectively, we present a scheduling rule by which the wafer flow time can be effectively controlled while minimizing the productivity loss caused by the increased tool cycle time. The introduced scheduling approach provides practical insights and numerical validation, offering semiconductor manufacturers a viable strategy to enhance both wafer quality and production efficiency.