Chemical mechanical polishing apparatus

Abstract

The chemical mechanical polishing (CMP) apparatus includes an insert pad that forms a local step on an upper surface of a polishing pad assembly. The insert pad is interposed between a rotatable platen and the polishing pad assembly.

1 . A chemical mechanical polishing (CMP) apparatus comprising: 
 a rotatable platen;    a polishing pad assembly disposed on the platen; and    an insert pad structure disposed between the platen and the polishing pad assembly.    
     
     
         2 . The apparatus of  claim 1 , wherein the polishing pad assembly is a composite polishing pad formed of a soft polishing pad and a hard polishing pad.  
     
     
         3 . The apparatus of  claim 1 , wherein the insert pad structure is 0.5˜300 mm thick.  
     
     
         4 . The apparatus of  claim 1 , wherein the insert pad structure is formed of plastic, ceramic, or metal.  
     
     
         5 . The apparatus of  claim 1 , wherein the insert pad is adhered to an upper surface of the platen by an adhesive.  
     
     
         6 . The apparatus of  claim 1 , wherein 
 the platen includes an upper surface with an annular-shaped polishing area that corresponds to a location where a wafer faces the polishing pad assembly during a CMP process;    the polishing area includes a central polishing area, which is located under the polishing pad assembly and faces a central portion of the wafer, and outer polishing areas, which are located under the polishing pad assembly and face an outer portion of the wafer.    
     
     
         7 . The apparatus of  claim 6 , wherein the insert pad structure includes an insert pad covering only the central polishing area.  
     
     
         8 . The apparatus of  claim 7 , wherein the insert pad is formed of an annular-shaped film having inner and outer edges.  
     
     
         9 . The apparatus of  claim 8 , wherein the insert pad has vertical sidewalls at the inner and outer edges.  
     
     
         10 . The apparatus of  claim 9 , wherein the insert pad is 0.5˜2 mm thick.  
     
     
         11 . The apparatus of  claim 8 , wherein the insert pad has sloped sidewalls at the inner and outer edges.  
     
     
         12 . The apparatus of  claim 11 , wherein the insert pad is 2˜300 mm thick.  
     
     
         13 . The apparatus of  claim 6 , wherein the insert pad structure covers only the outer polishing areas.  
     
     
         14 . The apparatus of  claim 13 , wherein the insert pad structure comprises: 
 a first insert pad that covers a central portion of the upper surface of the platen and a second insert pad that covers an outer portion of the upper surface of the platen.    
     
     
         15 . The apparatus of  claim 14 , wherein the first insert pad is formed of a circular or annular-shaped film.  
     
     
         16 . The apparatus of  claim 14 , wherein the second insert pad is formed of an annular-shaped film.  
     
     
         17 . The apparatus of  claim 14 , wherein the first and second insert pads are separated from each other at a distance corresponding to the central polishing area.  
     
     
         18 . The apparatus of  claim 14 , wherein the first and second insert pads have a vertical sidewall at each edge thereof.  
     
     
         19 . The apparatus of  claim 18 , wherein the insert pad is 0.5˜2 mm thick.  
     
     
         20 . The apparatus of  claim 14 , wherein the first and second insert pads insert pads have at least one sloped sidewall at an edge thereof.  
     
     
         21 . The apparatus of  claim 12 , wherein the insert pad is 2˜300 mm thick.  
     
     
         22 . A chemical mechanical polishing apparatus, comprising: 
 a rotatable platen; and    a polishing pad structure having a non-planar surface disposed on the platen.    
     
     
         23 . The apparatus of  claim 22 , wherein the polishing pad structure has at least one thick portion and at least one thin portion, the thick portion having a greater thickness than the thin portion.  
     
     
         24 . The apparatus of  claim 22 , wherein the thick portion is over an area of the platen corresponding to central portion of a wafer to be polished.  
     
     
         25 . The apparatus of  claim 24 , wherein the thin portions are over an area of the platen corresponding to outer portions of the wafer to be polished.  
     
     
         26 . The apparatus of  claim 23 , wherein the thick portions are over an area of the platen corresponding to output portions of a wafer to be polished.  
     
     
         27 . The apparatus of  claim 26 , wherein the thin portion is over an area of the platen corresponding to a central portion of the wafer to be polished.  
     
     
         28 . The apparatus of  claim 22 , wherein the polishing pad structure comprises: 
 a polishing pad assembly; and    an insert pad structure disposed between the polishing pad assembly and the platen.