半导体硅片加工过程复合控制策略研究及仿真

Research and Simulation of Compound Controlling Strategy in Semiconductor Wafer Fabrication

复合优先级控制策略CPC是一种兼顾投料与调度策略的生产过程综合控制策略。通过比较加工任务的复合优先级系数,CPC策略能够确定下一个加工任务,以及决定何时投放新工件。CPC策略甚至能够暂停非瓶颈设备以避免瓶颈设备前的在制品堆积。仿真结果表明,这种复合控制策略是一种能够同时优化多种性能指标的生产过程控制策略,可降低加工周期及其方差,减少生产过程中的在制品数,提高设备利用率及生产率等。

A new compound priority control strategy, CPC, is discussed, which integrates the scheduling and lot release policies into a whole. The compound priority measure is composed by seven sub-priority items. By comparing the compound priorities of jobs that compete with for processing, the CPC strategy can determine which lot（s） is/are processed when the machine is available, and when the new lot（s） is/are released into the wafer fab. The CPC can halt the non-bottleneck machines to prevent overstock of WlP before the bottleneck machines. The simulation results indicate that the CPC strategy has higher performance in reducing the cycle time and its standard deviation, decreasing the WIP inventory, and increasing utilization of machines and fab＇s throughput rate.