Timed Move Command for improved on-time AMHS delivery

This paper introduces the concept of Timed Move Command used in the AMHS Control System as a method to meet on-time delivery requirements of equipment in a modern 300 mm fab. It describes how the implementation of Timed Move Commands can ensure on-time delivery of wafers to equipment operated with 12 wafers per lot without the use of costly equipment buffers or an increased number of load ports. Several operational scenarios are presented for equipment which has a CET budget as small as 3 minutes. The paper discusses also the resulting AMHS requirements.