Lot identification, lot location and information distribution using radio frequency and ultrasonic signals

A new lot location and identification system (LotTrack) is presented. It shows, how the combination of radio frequency and ultrasonic signals enriches flexible wafer fabrication and leads to improved logistics. LotTrack localizes wafer boxes autonomously on the shop floor with an accuracy of 30 cm and displays any relevant information for operation. In this way the system turns into an alternative to more expensive and inflexible transport systems