Wafer edge with light sensor

Abstract

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 comprises a receiving member that is coupled to an end effector and a light sensor that is operatively coupled to the receiving member and is configured to detect an amount light transmitted by the receiving member. In a modified embodiment, the apparatus also includes a transmitting member that receives light from a light source and is also coupled to the end effector.

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;    a first transmitting member that is coupled to the end effector such that the first transmitting member moves with the end effector; and    a light source that is operatively coupled to the first transmitting member and is configured to transmit an amount of light to the first transmitting member.    
   
   
       2 . The apparatus as in  claim 1 , wherein the apparatus is positioned within a sealed environment and the apparatus further comprises a wireless data transmitter that is positioned in the sealed environment and is configured to transmit information to a point beyond the sealed environment.  
   
   
       3 . The apparatus as in  claim 1 , further comprising a photoelectric cell configured to provide power to the light sensor.  
   
   
       4 . The apparatus as in  claim 1 , further comprising a photoelectric cell configured to provide power to the control system.  
   
   
       5 . 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;    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;    a first transmitting member that is coupled to the end effector such that the first transmitting member moves with the end effector; and    a light source that is operatively coupled to the first transmitting member and is configured to transmit an amount of light to the first transmitting member;    wherein, when the substrate is being properly carried on the end effector, at least a portion of the amount of light transmitted by the first transmitting member is reflected off of a lower surface of the substrate at an angle and is received by the first receiving member to indicate the presence of the substrate on the end effector.    
   
   
       6 . The apparatus as in  claim 5 , wherein the first receiving member and the first transmitting member have a tip portions that are generally perpendicular to elongated portions of the first receiving member and the first transmitting member.  
   
   
       7 . The apparatus as in  claim 5 , further comprising a photoelectric cell configured to provide power to the apparatus.  
   
   
       8 . 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 second receiving member that is coupled to the end effector such that the second receiving member moves with the end effector;    a light sensor that is operatively coupled to the first receiving member and the second receiving member and is configured to detect an amount of light transmitted by the first and second receiving members;    a first transmitting member that is coupled to the end effector such that the first transmitting member moves with the end effector;    a second transmitting member that is coupled to the end effector such that the second transmitting member moves with the end effector;    a light source that is operatively coupled to the first and second transmitting members and is configured to transmit an amount of light through the first and second transmitting members; 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, when the substrate is being properly carried on the end effector, at least a portion of the amount of light transmitted by the first transmitting member is reflected off of a lower surface of the substrate at an angle and is received by the first receiving member to indicate the presence of the substrate on the end effector.    
   
   
       9 . A method for monitoring the position of a substrate within a substrate processing system, comprising: 
 providing a first receiving member that is coupled to an end effector of the substrate processing system;    providing a light detection sensor, which is operatively coupled to the first receiving member;    detecting the presence of a substrate when the first receiving member receives a first amount of light; and    detecting the absence of a substrate when the first receiving member receives a second amount of light that is greater than the first amount of light;    wherein, when the substrate is present, a lower surface of the substrate reflects light at an angle from a transmitting member into the first receiving member.    
   
   
       10 . A method for monitoring the position of a substrate within a substrate processing system, comprising: 
 providing a first receiving member that is coupled to an end effector of the substrate processing system;    providing a light detection sensor, which is operatively coupled to the first receiving member;    providing a first transmitting member that is also coupled to an end effector of the substrate processing system;    providing a light source, which is operatively coupled to the first transmitting member;    detecting the presence of a substrate when the first receiving member receives light from the first transmitting member that is reflected off of a lower surface of the substrate at an angle; and    detecting the absence or misalignment of a substrate when the first receiving member does not receive light from the first transmitting member that is reflected off of a lower surface of the substrate.    
   
   
       11 . A method as in  claim 10 , further comprising: 
 providing a second receiving member that is coupled to the end effector;    providing a second transmitting member that is also coupled to an end effector;    detecting the absence or misalignment of a substrate when the first receiving member does not receive light from the first transmitting member and the second receiving member does not receive light from the second transmitting member; and    detecting the position of a substrate when the first receiving member receives light from the first transmitting member that is reflected off of the substrate and the second receiving member does not receive light from the second transmitting member.    
   
   
       12 . A method for monitoring the position of a substrate within a substrate processing system, comprising: 
 providing a first receiving member that is coupled to an end effector of the substrate processing system;    providing a second receiving member that is coupled to the end effector;    providing a light detection sensor, which is operatively coupled to the first receiving member and the second receiving member;    providing a first transmitting member that is also coupled to an end effector of the substrate processing system;    providing a second transmitting member that is also coupled to an end effector;    providing a light source, which is operatively coupled to the first transmitting member and the second transmitting member;    detecting the absence or misalignment of a substrate when the first receiving member does not receive light from the first transmitting member that has be been reflected off of a lower surface of the substrate and the second receiving member does not receive light from the second transmitting member that has be been reflected off of the lower surface of the substrate;    detecting the position of a substrate when the first receiving member receives light from the first transmitting member that is reflected off of the lower surface of the substrate at an angle and the second receiving member does not receive light from the second transmitting member that has been reflected off of the lower surface of the substrate; and    detecting the misalignment of a substrate when the first receiving member receives light from the first transmitting member that is reflected off of the lower surface of the substrate and the second receiving member receives light from the second transmitting member that is also reflected off of the lower surface of the substrate.