Ceramic end effector for micro circuit manufacturing

Abstract

An end effector for installation on a robotic arm for transporting a plurality of semiconductor wafers from one location to another features a ceramic end effector body portion that includes a plurality of wafer engaging fingers that each feature wafer support pads. The wafer support pads are adapted to support a semiconductor wafer surface, and at least one of the support pads has a vacuum orifice. The pads are replaceable and/or removable in case of damage or contamination. The support pads are attached to the body in such a way as to allow differential thermal expansion so as to prevent introduction of stress into the components. Typically, a wire spring is employed to secure the pad to the end effector. The body portion features an interior vacuum passageway having a first end that is adapted to connect to a vacuum source and a second end that terminates at the vacuum orifices such that a reduced gas pressure at the first end causes a vacuum to be exerted at the vacuum orifices. The interior passageway is formed from a groove in the end effector body portion and an end effector backplate that is sealingly connected to the end effector body portion to completely cover the groove from the first end to the second end. The ceramic body portion can be made of alumina or silicon carbide.

1 . For use in the processing of semiconductor wafers, an end effector for installation on a robotic arm for transporting a plurality of semiconductor wafers from one location to another, the end effector comprising: 
 a ceramic end effector;    a plurality of removable wafer support pads disposed at a distal end of said end effector said support pads being adapted to support a semiconductor wafer surface, wherein at least one of the support pads comprises a vacuum orifice in communication with a vacuum source for exerting a vacuum on the wafer surface; and    a retaining structure for removably securing the removable support pads to the end effector.    
   
   
       2 . The end effector of  claim 1  wherein said end effector body includes an interior vacuum passageway having a first end that is adapted to connect to a vacuum source and a second end that terminates at a vacuum aperture, said aperture communicating with the support pad vacuum orifice such that a reduced gas pressure at the first end causes a vacuum to be exerted at the vacuum orifice of the support pad.  
   
   
       3 . The end effector of  claim 2  wherein the interior passageway is formed from a groove in the end effector body portion and an end effector backplate that is sealingly connected to the end effector body portion to completely cover the groove from the first end to the second end.  
   
   
       4 . The end effector of  claim 1  wherein the ceramic body is made of alumina.  
   
   
       5 . The end effector of  claim 1  wherein the ceramic body is made of silicon carbide.  
   
   
       6 . The end effector of  claim 1  wherein the end effector body comprises a plurality of wafer engaging fingers at the distal end.  
   
   
       7 . The end effector of  claim 6  wherein the wafer support pads are disposed at an axial end of the wafer engaging fingers.  
   
   
       8 . The end effector of  claim 6  comprising three wafer engaging fingers, two of which comprise wafer support pads that include vacuum orifices.  
   
   
       9 . The end effector of  claim 6  wherein at least one of the wafer engaging fingers includes a cavity which houses a vacuum support pad.  
   
   
       10 . The end effector of  claim 1  wherein said retaining structure is a spring clip, said spring clip extending through a portion of the body of the wafer engaging finger, into said cavity and making torsional engagement with the vacuum pad such that said spring clip secures the pad in the cavity.  
   
   
       11 . The end effector of  claim 1  wherein the vacuum support orifice includes a counterbore to enhance a seal between the vacuum pad and end effector during expansion or contraction of the end effector components.  
   
   
       12 . The end effector of  claim 1  wherein the vacuum pad is ground flat at that portion which engages the end effector to create a vacuum seal with low leakage.  
   
   
       13 . For use in the processing of semiconductor wafers, an end effector for installation on a robotic arm for transporting at least one of semiconductor wafers from one location to another, the end effector comprising: 
 a ceramic end effector body portion including a plurality of wafer engaging fingers;    a plurality of removable wafer support pads disposed at an axial end of the wafer engaging fingers, said support pads being adapted to support a semiconductor wafer surface, wherein at least one of the support pads comprises a vacuum orifice in communication with a vacuum source for exerting a vacuum on the wafer surface; and    a retaining structure for removably securing the removable support pads to the end effector.    
   
   
       14 . The end effector of  claim 13  wherein the ceramic body is made of alumina.  
   
   
       15 . The end effector of  claim 13  wherein the ceramic body is made of silicon carbide.  
   
   
       16 . The end effector of  claim 13  wherein at least one of the wafer engaging fingers includes a cavity which houses a vacuum support pad.  
   
   
       17 . The end effector of  claim 13  wherein said retaining structure is a spring clip, said spring clip extending through a portion of the body of the wafer engaging finger, into said cavity and making torsional engagement with the vacuum pad such that said spring clip secures the pad in the cavity.  
   
   
       18 . The end effector of  claim 13  wherein the vacuum support orifice includes a counterbore to enhance a seal between the vacuum pad and end effector during expansion or contraction of the end effector components.  
   
   
       19 . The end effector of  claim 13  comprising three wafer engaging fingers, two of which comprise wafer support pads that include vacuum orifices.  
   
   
       20 . The end effector of  claim 13  wherein at least one of the wafer engaging fingers includes a cavity which houses the vacuum support pad.  
   
   
       21 . For use in the processing of semiconductor wafers, an end effector for installation on a robotic arm for transporting at least one of semiconductor wafers from one location to another, the end effector comprising: 
 a ceramic end effector body including three wafer engaging fingers, at least one of which comprise wafer support pads that include vacuum orifices;    a plurality of removable wafer support pads disposed in a cavity at an axial end of the wafer engaging fingers, said support pads being adapted to support a semiconductor wafer surface, wherein at least one of the support pads comprises a vacuum orifice in communication with a vacuum source for exerting a vacuum on the wafer surface; and    a retaining structure comprising a spring clip, said spring clip extending through a portion of the body of the wafer engaging finger, into said cavity and making torsional engagement with the pad such that said spring clip secures the pad in the cavity.    
   
   
       22 . For use in the processing of semiconductor wafers, an end effector for installation on a robotic arm for transporting at least one of semiconductor wafers from one location to another, the end effector comprising: 
 a ceramic end effector body including an interior vacuum passageway having a first end that is adapted to connect to a vacuum source and a second end that terminates at a first vacuum orifice such that a reduced gas pressure at the first end causes a vacuum to be exerted at the fist vacuum orifice;    a plurality of removable wafer support pads secured to said end effector body portion said support pads being adapted to support a semiconductor wafer surface, wherein at least one of the support pads comprises a second vacuum orifice in communication with said first vacuum orifice such that a vacuum is exerted on the wafer surface; and    a retaining structure for securing the removable support pads to the end effector.    
   
   
       23 . A method of securing a semiconductor wafer support pad to an end effector, said end effector for use in thermal processing of the semiconductor wafer wherein the end effector is installed on a robotic arm for transporting at least one of semiconductor wafers from one location to another, the method comprising the steps of: 
 placing a plurality of wafer support pads in contact with the end effector, wherein at least one of said pads including a vacuum orifice in communication with a vacuum source; and    securing the wafer support pads to the end effector with a retaining structure.    
   
   
       24 . The method of  claim 23  wherein the end effector comprises a plurality of wafer engaging fingers.  
   
   
       25 . The end effector of  claim 24  wherein the wafer support pads are disposed at an axial end of the wafer engaging fingers.  
   
   
       26 . The method of  claim 25  wherein at least one of the wafer engaging fingers includes a cavity which houses the vacuum support pad.  
   
   
       27 . The method of  claim 26  wherein said retaining structure is a spring clip, said spring clip extending through a portion of the body of the wafer engaging finger, into said cavity and making torsional engagement with the pad such that said spring clip secures the pad in the cavity