Chemical mechanical polishing system with conditioning ring

Abstract

A chemical mechanical polishing (CMP) system includes a polishing pad mounted upon a platen, a wafer carrier configured to hold a substrate on its backside and press the substrate against the polishing pad, and a pad conditioner that includes a conditioner head and a conditioning ring which is held by the conditioner head. The conditioning ring extends from the center of the polishing pad to the edge of the polishing pad, for simultaneous conditioning along the entire radius of the polishing pad. The conditioning ring is better able to remove pad debris. Also described are systems in which one pad conditioner is used for conditioning multiple polishing pads on multiple platens.

1 . A method for conditioning a polishing pad of a chemical mechanical polishing (CMP) system for semiconducting wafer substrates, comprising:
 conditioning the polishing pad using a rotating conditioning ring.   
     
     
         2 . The method of  claim 1 , further comprising polishing a wafer substrate using the polishing pad, wherein the polishing pad is conditioned concurrently with or prior to the polishing of the wafer substrate. 
     
     
         3 . The method of  claim 1 , further comprising passing the conditioning ring over a rinse bar, the rinse bar being located beyond a perimeter of the polishing pad. 
     
     
         4 . The method of  claim 1 , wherein the conditioning ring has a diameter that is equal to or greater than a radius of the polishing pad. 
     
     
         5 . The method of  claim 1 , wherein the conditioning ring has a circular, elliptical, or rectangular shape. 
     
     
         6 . The method of  claim 1 , wherein the conditioning ring has a major axis length and a minor axis width, and a ratio of the major axis length to the minor axis width is from about 1.3 to about 1.8. 
     
     
         7 . The method of  claim 1 , wherein an outer perimeter of a contact surface of the conditioning ring is rounded. 
     
     
         8 . The method of  claim 1 , wherein the conditioning ring comprises diamond particles embedded within a matrix, or comprises a brush. 
     
     
         9 . The method of  claim 1 , wherein the conditioning ring comprises an inner ring and an outer ring, the inner ring comprising a brush and the outer ring comprising diamond particles embedded within a matrix. 
     
     
         10 . The method of  claim 1 , wherein the conditioning ring has an inner radius of about 300 mm to about 400 mm. 
     
     
         11 . The method of  claim 1 , wherein the conditioning ring has an outer radius of about 350 mm to about 500 mm. 
     
     
         12 . The method of  claim 1 , wherein the conditioning ring has a width of about 10 mm to about 200 mm. 
     
     
         13 . The method of  claim 1 , wherein the polishing pad is a first polishing pad mounted upon a first platen, and wherein the method further comprises:
 conditioning a second polishing pad mounted upon a second platen using the rotating conditioning ring.   
     
     
         14 . The method of  claim 13 , wherein the first polishing pad and the second polishing pad are concurrently conditioned. 
     
     
         15 . A chemical mechanical polishing (CMP) system for semiconducting wafer substrates, comprising:
 a first polishing pad mounted upon a first platen;   a first wafer carrier that can be positioned above the first polishing pad; and   a pad conditioner comprising a rotatable conditioning ring.   
     
     
         16 . The CMP system of  claim 15 , wherein the pad conditioner is mounted upon a movable arm that can move between a center and a perimeter of the first polishing pad; and
 wherein the pad conditioner comprises a rotatable pad conditioner head and the conditioning ring is affixed to an underside of the pad conditioner head.   
     
     
         17 . The CMP system of  claim 15 , further comprising a second polishing pad mounted upon a second platen; wherein the pad conditioner is configured to simultaneously condition the first polishing pad and the second polishing pad. 
     
     
         18 . The CMP system of  claim 15 , further comprising a second wafer carrier above the first polishing pad, wherein the first polishing pad is configured to simultaneously polish wafer substrates mounted on the first wafer carrier and the second wafer carrier. 
     
     
         19 . A method for planarizing a top layer of a wafer substrate, comprising:
 pushing the top layer against a polishing pad using a wafer carrier to which the wafer substrate is attached; and   in-situ conditioning the polishing pad using a pad conditioner while the top layer is being polished by the polishing pad;   wherein the pad conditioner comprises a rotating conditioning ring.   
     
     
         20 . The method of  claim 19 , wherein the polishing pad and the pad conditioner both rotate clockwise or both rotate counter-clockwise.