An apparatus for monitoring a position of a semiconductor process fluid interface in a dispense nozzle includes an extended optical source adapted to provide an optical beam propagating along an optical path. The optical beam is characterized by a path width measured in a first direction aligned with...http://www.google.ca/patents/US7935948?utm_source=gb-gplus-sharePatent US7935948 - Method and apparatus for monitoring and control of suck back level in a photoresist dispense system
