System and method for monitoring quality control of chemical mechanical polishing pads

Abstract

The present invention provides a method for predicting a performance characteristic of a chemical mechanical polishing (CMP) pad. The method comprises providing a CMP pad having a polishing surface and measuring a frictional property of the polishing surface. The method further includes estimating a performance characteristic of the CMP pad based on the frictional property. Other aspects of the present invention include a quality control system for monitoring chemical mechanical polishing pad performance.

1 . A method for predicting a performance characteristic of a chemical mechanical polishing pad, comprising: 
 providing a chemical mechanical polishing (CMP) pad having a polishing surface;    measuring a frictional property of said polishing surface; and    estimating a performance characteristic of said CMP pad based on said frictional property.    
   
   
       2 . The method as recited in  claim 1 , wherein said frictional property comprises a static coefficient of friction.  
   
   
       3 . The method as recited in  claim 1 , wherein said frictional property comprises a dynamic coefficient of friction.  
   
   
       4 . The method as recited in  claim 1 , wherein said CMP pad comprises a thermoplastic foam substrate comprising a blend of a crosslinked ethylene vinyl acetate copolymer and a low-density polyethylene copolymer, and said polishing surface comprises concave cells.  
   
   
       5 . The method as recited in  claim 1 , wherein estimating said performance characteristic comprises comparing said frictional property to a database, wherein said database provides a functional relationship between said frictional property and said performance characteristic.  
   
   
       6 . The method as recited in  claim 1 , wherein said performance characteristic comprises a removal rate of a material from a substrate.  
   
   
       7 . The method as recited in  claim 6 , wherein said material comprises a metal layer, a barrier layer, a dielectric films, or combinations thereof.  
   
   
       8 . The method as recited in  claim 7 , wherein said metal layer comprises a refractory metal or a noble metal.  
   
   
       9 . The method as recited in  claim 1 , wherein said performance characteristic comprises a within substrate uniformity.  
   
   
       10 . The method as recited in  claim 1 , wherein said frictional property is measured using a detector comprising a tribometer and said performance characteristic is estimated using a controller comprising a computer.  
   
   
       11 . A quality control system for monitoring chemical mechanical polishing pad performance, comprising: 
 a detector configured to determine a frictional property of a surface of a chemical mechanical polishing (CMP) pad; and    a controller coupled to said detector and configured to estimate a performance characteristic of said CMP pad surface based on said frictional property.    
   
   
       12 . The quality control system as recited in  claim 11 , wherein said frictional property comprises a static coefficient of friction.  
   
   
       13 . The quality control system as recited in  claim 11 , wherein said frictional property comprises a dynamic coefficient of friction.  
   
   
       14 . The quality control system as recited in  claim 11 , wherein said CMP pad comprises a thermoplastic foam substrate comprising a blend of a crosslinked ethylene vinyl acetate copolymer and a low-density polyethylene copolymer, and said polishing surface comprises concave cells.  
   
   
       15 . The quality control system as recited in  claim 11 , wherein said controller adjusts one or more polishing parameter of a polishing apparatus coupled to said controller, based on said estimated performance characteristic.  
   
   
       16 . The quality control system as recited in  claim 15 , wherein said controller adjusts one or more polishing parameter for a subsequent batch of wafers based on said estimated performance characteristic for a previous batch of wafers.  
   
   
       17 . The quality control system as recited in  claim 15 , wherein said polishing parameter comprises a rotational speed of a platen of said polishing apparatus.  
   
   
       18 . The quality control system as recited in  claim 15 , wherein said polishing parameter comprises a rotational speed of a carrier head of said polishing apparatus.  
   
   
       19 . The quality control system as recited in  claim 15 , wherein said polishing parameter comprises a down-force imparted by a carrier head against said CMP pad surface.  
   
   
       20 . The quality control system as recited in  claim 15 , wherein said polishing parameter comprises a duration of polishing.  
   
   
       21 . The quality control system as recited in  claim 11 , wherein said controller rejects a chemical mechanical polishing pad produced by a manufacturing apparatus coupled to said controller based, on said estimated performance characteristic.