Cmp pad identification and layer ratio modeling

Abstract

The present invention relates to methods and apparatus for improving productivity of chemical mechanical polishing (CMP) processes and lowering operating costs of CMP systems. Embodiments of the present invention provide a method for improving the ratio of the layer thickness of composite polishing pads for improved removal rates. Embodiments of the present also provide specific polishing pad identification for monitoring and controlling processes developed for the specific pad to improve overall productivity and reduce downtime of the CMP system.

1 . A substrate polishing apparatus, comprising:
 a platen with a polishing pad including an identification member attached to or embedded in the polishing pad; and   an identification member reader configured to read information from the identification member and transfer the information read from the identification member to a system controller, wherein the system controller is programmed to retrieve information specific to the polishing pad from system controller memory based on the information read from the identification member.   
   
   
       2 . The apparatus in  claim 1 , wherein the identification member is a barcode, and wherein the identification member reader is a barcode scanner. 
   
   
       3 . The apparatus in  claim 1 , wherein the identification member is a radio frequency identification tag, and wherein the identification member reader is a radio frequency identification tag reader. 
   
   
       4 . The apparatus of  claim 1 , wherein the system controller is further programmed to use the retrieved information for controlling polishing processes. 
   
   
       5 . The apparatus of  claim 1 , further comprising a composition delivery device, wherein the system controller is further programmed to use the retrieved information to control the delivery rate of composition delivered by the composition delivery device. 
   
   
       6 . The apparatus of  claim 5 , wherein the system controller is further programmed to use the retrieved information to control a chemical slurry recipe delivered by the composition delivery device. 
   
   
       7 . The apparatus of  claim 1 , wherein the system controller is further programmed to retrieve information specific to burning in the polishing pad and to control a burn in procedure for the polishing pad using the retrieved information. 
   
   
       8 . The apparatus of  claim 1 , further comprising a polishing pad conditioning apparatus, wherein the system controller is further programmed to use the retrieved information to control parameters of the polishing pad conditioning apparatus. 
   
   
       9 . The apparatus of  claim 1 , wherein the polishing pad is a composite polishing pad, comprising:
 an upper polishing pad; and   a lower polishing pad, wherein the lower polishing pad is more compliant than the upper polishing pad, and wherein the ratio of the thickness of the upper polishing pad to the thickness of the lower polishing pad is between about 0.73 to about 0.57.   
   
   
       10 . A method for selectively improving properties of a composite polishing pad, comprising:
 selectively testing parameters of a composite polishing pad having an upper pad and a lower pad, wherein the polishing pad has an initial overall thickness, an initial upper pad thickness, and an initial lower pad thickness, and wherein the parameters are selectively tested while the thickness of the lower pad is varied until desired parameter improvements are achieved;   identifying an improved lower pad thickness resulting from the selectively testing composite polishing pad parameters;   computing a second composite polishing pad thickness comprising the sum of the initial upper pad thickness and the improved lower pad thickness;   computing a thickness ratio, wherein the thickness ratio comprises the ratio of the initial upper pad thickness to the improved lower pad thickness; and   resealing the initial upper pad thickness and the improved lower pad thickness using the computed thickness ratio to achieve a final composite pad thickness substantially equal to the initial composite pad thickness.   
   
   
       11 . The method of  claim 10 , wherein the varying the thickness of the lower pad comprises increasing the thickness of the lower pad. 
   
   
       12 . The method of  claim 10 , wherein the polishing pad parameters comprise a feature removal rate for a given chemical slurry recipe. 
   
   
       13 . A method for selectively improving properties of a composite polishing pad, comprising:
 selectively testing parameters of a composite polishing pad having an upper pad and a lower pad, wherein the polishing pad has an initial overall thickness, an initial upper pad thickness, and an initial lower pad thickness, and wherein the parameters are selectively tested while varying the thickness of the upper pad until desired parameter improvements are achieved;   identifying an improved upper pad thickness resulting from the selectively testing composite polishing pad parameters;   computing a second composite polishing pad thickness comprising the sum of the initial lower pad thickness and the improved upper pad thickness;   computing a thickness ratio, wherein the thickness ratio comprises the ratio of the improved upper pad thickness to the initial lower pad thickness; and   resealing the initial lower pad thickness and the improved upper pad thickness using the computed thickness ratio to achieve a final composite pad thickness substantially equal to the initial composite pad thickness.   
   
   
       14 . The method of  claim 13 , wherein the varying the thickness of the upper pad comprises increasing the thickness of the upper pad. 
   
   
       15 . The method of  claim 13 , wherein the polishing pad parameters comprise a feature removal rate for a given chemical slurry recipe. 
   
   
       16 . A polishing device, comprising:
 a polishing pad with a polishing side and a non-polishing side; and   an identification member attached to or embedded in the non-polishing side of the polishing pad.   
   
   
       17 . The polishing device of  claim 16 , wherein the polishing pad is a composite polishing pad, comprising:
 an upper polishing pad; and   a lower polishing pad, wherein the lower polishing pad is more compliant than the upper polishing pad, and wherein the ratio of the thickness of the upper polishing pad to the thickness of the lower polishing pad is between about 0.73 and about 0.57.   
   
   
       18 . The polishing device of  claim 17 , wherein the identification member is a barcode imprinted on the non-polishing side of the polishing pad. 
   
   
       19 . The polishing pad of  claim 17 , wherein the identification member is a radio frequency identification tag embedded within the non-polishing side of the polishing pad.