Patent ID: 7235806
Filing Date: 2007-06-26
Classification: H01L

Abstract:
1. An apparatus for detecting the presence of a substrate that is carried by an end effector of a substrate handling assembly positioned within a substrate processing system, the apparatus comprising: a first receiving member that is coupled to the end effector such that the first receiving member moves with the end effector; a light sensor that is operatively coupled to the first receiving member and is configured to detect an amount of light received by the first receiving member; and a control system operatively coupled to the light sensor and configured to indicate the presence of the substrate based upon the amount of light detected by the light sensor; wherein a tip portion of the first receiving member is positioned such that, when the substrate is properly carried by the end effector in a first position, the substrate substantially blocks ambient light from being received by the tip portion of the first receiving member and wherein the apparatus does not include a transmitting member coupled to the end effector and configured to transmit light into the first receiving member.