A wet processing device of this invention is comprised of a chemical processing tank to store chemicals for processing the surface of the wafer, a wafer conveyor device to carry the wafer in and out of the interior of the chemical processing tank, and a sensor to determine the amount of air bubbles occurring...http://www.google.com.au/patents/US6612316?utm_source=gb-gplus-sharePatent US6612316 - Wet processing device with sensor-controlled conveyor
