Enhanced end effector arm arrangement for CMP pad conditioning

Abstract

A CMP conditioning apparatus enhanced end effector arm for improving the reliability of the apparatus and the quality of the conditioning and polishing operations includes a conditioner head with features that provide for simplified alignment/attachment of a conditioning disk to the arm, while also providing a “quick release” mechanism for maintenance operations. The enhanced arm also includes an improved actuator that provides for a static friction (“stiction”)-free movement of the arm and better control of the downforce applied by the conditioning disk to the polishing pad. A dual-drive pulley system is used within the enhanced end effector arm to minimize the tilting of the drive belts within the effector arm as the arm pivots to follow the contour of an “aging” polishing pad.

1 . A conditioner head for use in an end effector arm of a CMP system, the conditioner head comprising: 
 an abrasive conditioning disk including a magnetic-filled central aperture;    a keyed alignment/attachment element disposed to contact the abrasive conditioning disk, the keyed alignment element comprising an impeller body having a central recessed portion of a known keying geometry and including at least one magnetic component disposed within the central recessed portion so as to align with the magnetic-filled central aperture of the abrasive conditioning disk; and    at least one ejector mechanism disposed at the periphery of the conditioner head and configured to impart a downward force onto the abrasive conditioning disk sufficient to break the magnetic attachment provided by the keyed alignment/attachment element when needed to remove the abrasive conditioning disk from the conditioner head.    
   
   
       2 . An actuator mechanism for a CMP end effector arm capable of providing precise control of a downforce applied by a conditioner head on a polishing pad, the actuator mechanism comprising a piston and a cylinder for housing the piston, the piston and the cylinder formed from materials that generate minimal static friction as the piston is moved within the cylinder.  
   
   
       3 . An actuator mechanism as defined in  claim 2  wherein the piston comprises a graphite material and the cylinder comprises a glass material and the actuator mechanism further comprises: 
 a first evacuation channel disposed along a top surface thereof; and    a second evacuation channel disposed along an opposing bottom surface, wherein as vacuum is applied the graphite piston rides within the glass cylinder and air is evacuated along at least one of the first evacuation channel and the second evacuation channel into the end effector arm.    
   
   
       4 . A CMP end effector arm including a dual drive belt movement arrangement disposed between a conditioner head and an actuator mechanism for translating the actuator mechanism movement into movement of the conditioner head, the dual drive belt movement arrangement comprising 
 a first drive belt coupled at a first end to the conditioner head;    a pulley disposed within the end effector arm and coupled to a second, opposing end of the first drive belt;    a second drive belt coupled at a first end to the actuator mechanism and at a second, opposing end to the pulley, wherein movement of the actuator passes through the second drive belt and is thereafter coupled by the pulley into the first drive belt, thereby resulting in movement of the conditioner head, the pulley being located along the end effector arm at a position that minimizes movement of the pulley during pivoting of the end effector arm.    
   
   
       5 . A method for controlling the application of an abrasive conditioning disk to a polishing pad in a CMP conditioning system such that zero downforce is applied to the conditioning disk, the method comprising the steps of: 
 engaging an actuator mechanism to control movement of an end effector arm, wherein said actuator mechanism further comprises a piston and a cylinder for housing the piston and wherein the piston and the cylinder are formed from materials that generate minimal static friction as the piston is moved within the cylinder.