| 摘要 |
<p>A method and apparatus for controlling a multiple chamber semiconductor wafer processing system. The processing system includes a plurality of process chambers about the periphery of the transfer chamber. A centrally located wafer transfer mechanism effects moving wafers between the process chambers. The process sequencer control is a real time, multi-tasking control program having a presequencer or look ahead feature for preventing delays in the processing. In one implementation, the look ahead feature indentifies mid-sequence or oriented wafers which cannot be further processed because their destination chamber is busy. Rather than expend system resources waiting for the destination chamber to become available, the wafers are transferred to a holding position, preferably the load lock, and rescheduled at the earliest time to finish their processing.</p> |
