Impacts of small lot manufacturing on AMHS

Demands to reduce semiconductor fab lot cycle time are increasing more and more. Small lot manufacturing (SLM) is proposed as a promising way to reduce cycle times considerably. However there are detractors against realizing effective SLM. Some of them are related to Automated Manufacturing Handling System (AMHS). This paper describes these detractors and discuss potential solutions for them. We conclude that AMHS solutions for SLM should stress more transport capacity and shorter Carrier Exchange Time (CET) rather than shorter delivery time. We also conclude that mathematical models are more intuitive and useful than simulation models for such studies.