Chemical mechanical polishing tool, apparatus and method

Abstract

A chemical mechanical polishing tool, apparatus and method. The polishing tool includes a central polishing assembly comprised of a central pad mount on a central shaft. That central pad mount beneficially retains a center polishing pad. Also included is a ring polishing assembly comprised of a ring pad mount with a central aperture on a ring shaft with a central aperture. The ring pad mount beneficially retains a ring polishing pad having a central aperture. The central polishing assembly and the ring polishing assembly beneficially rotate and move axially independently of one another. The apparatus includes the CMP polishing tool and a rotating polishing table. The method includes rotating a semiconductor wafer on the rotating polishing table. Then, selectively and independently moving a solid center polishing pad having an axis of rotation and/or an axially aligned ring-shaped polishing pad into contact with the surface of the semiconductor wafer.

1 - 19 . (canceled)  
     
     
         20 . A polishing tool comprising: 
 a ring shaft assembly including: 
 a ring shaft;  
 a ring mount disposed on the ring shaft; and  
 a ring polishing pad mounted on the ring mount;  
   a central shaft assembly including: 
 a central shaft;  
 a central mount disposed on the central shaft; and  
 a center polishing pad having a solid polishing surface extending continuously across a diameter of the center polishing pad, wherein the center polishing pad is mounted on the central mount, wherein the central shaft passes through a center of both the ring shaft and the ring mount such that the central shaft and the ring shaft are co-axial, wherein the ring shaft moves independently of the central shaft during operation of the chemical mechanical polishing apparatus and wherein both the rim polishing pad and the center polishing pad polish a surface of the substrate.  
   
     
     
         21 . A polishing tool according to  claim 20 , wherein the central shaft assembly rotates independently of the ring shaft assembly.  
     
     
         22 . A polishing tool according to  claim 20 , wherein the central shaft assembly moves axially independently of the ring shaft assembly.  
     
     
         23 . A polishing tool according to  claim 20 , further including a center rotation mechanism for rotating the central polishing assembly, and a ring rotation mechanism for independently rotating the ring polishing assembly.  
     
     
         24 . A polishing tool according to  claim 20 , further including a center axial motion mechanism for moving the center polishing pad axially, and a ring axial motion mechanism for independently moving the ring polishing pad axially, wherein the center polishing pad and the ring polishing pad can be selectively and independently moved into contact with a surface of a semiconductor wafer retained on the polishing table.  
     
     
         25 . A polishing tool according to  claim 20 , further including a linear motion mechanism for moving the center polishing pad across a retained semiconductor wafer.