Overall equipment effectiveness in resist processing equipment

As fab equipment costs increase, semiconductor manufacturers are attempting to improve equipment utilization as a way to reduce overall cost per wafer. Photolithography equipment represents the highest percentage cost in construction of a typical fab. Flexibility in resist processing can improve the utilization of photolithography equipment. This study uses the Overall Equipment Effectiveness (OEE) model by SEMATECH to quantify the effect of flexibility on equipment utilization in a manufacturing environment. The OEE model measures three components of equipment utilization: rate of quality, availability and performance efficiency. Rate of quality can be approximated with yield data and availability is currently well measured. Performance efficiency is the least characterized component and provides the best opportunity for increasing OEE. This study focuses on the impact of flexibility in resist processing equipment on OEE. Improvements in performance efficiency and equipment utilization depend on the product being manufactured and the scale of production. Data collected at a medium-volume logic fab is presented. The effects of equipment configuration, material flow and operation efficiency are discussed.