Methods for conditioning polishing pads

Abstract

Methods for breaking-in new polishing pads of a double-side polishing apparatus for polishing substrates such as single crystal silicon wafers are disclosed. The methods may involve contacting the new polishing pads with a conditioning substrate such as a substate that includes diamonds at the surface of the substrate. Conditioning methods may also involve contacting the new polishing pad with sacrificial substrates.

What is claimed is: 
     
         1 . A method for conditioning new polishing pads in a double-side polishing apparatus having first and second platens and wafer carriers, the method comprising:
 mounting the new polishing pads on the first and second platens;   placing sacrificial wafers in the wafer carriers;   contacting the sacrificial wafers with the new polishing pads while supplying a first polishing fluid to the new polishing pads in a first polishing operation;   contacting the new polishing pads with a conditioning substrate; and   contacting sacrificial wafers with the new polishing pads while supplying a second polishing fluid to the new polishing pads in a second polishing operation.   
     
     
         2 . The method as set forth in  claim 1  wherein the conditioning substrate comprises diamonds. 
     
     
         3 . The method as set forth in  claim 2  wherein the conditioning substate is part of a conditioning substrate wheel, the conditioning substrate wheel being an annulus. 
     
     
         4 . The method as set forth in  claim 3  wherein:
 each wafer carrier comprises circumferential teeth for rotating the wafer carrier during the first and second polishing operations; and 
 each conditioning substrate wheel comprises circumferential teeth for rotating the conditioning substrate wheel, the wafer carriers and conditioning substrate wheels having the same diameter. 
 
     
     
         5 . The method as set forth in  claim 4  comprising;
 removing the wafer carriers from the polishing apparatus after the first polishing operation; and 
 positioning one conditioning substrate wheel on the polishing apparatus for every wafer carrier removed from the polishing apparatus. 
 
     
     
         6 . The method as set forth in  claim 1  comprising contacting the new polishing pads with an annular cleaning brush in a brushing operation, the brushing operation being prior to the second polishing operation. 
     
     
         7 . The method as set forth in  claim 6  wherein the brushing operation is a second brushing operation, the method comprising contacting the new polishing pads with an annular cleaning brush in a first brushing operation, the first brushing operation being prior to the first polishing operation, the same polishing brush being used in the first brushing operation and the second brushing operation. 
     
     
         8 . The method as set forth in  claim 1  wherein the same sacrificial wafers are used in the first polishing operation and the second polishing operation. 
     
     
         9 . The method as set forth in  claim 1  wherein different sacrificial wafers are used in the first polishing operation and the second polishing operation, the sacrificial wafers contacted with the new polishing pads in the first polishing operation being a first batch of sacrificial wafers, the method comprising placing a second batch of sacrificial wafers in the wafer carriers prior to the second polishing operation. 
     
     
         10 . The method as set forth in  claim 1  wherein the first and second polishing fluids have the same composition. 
     
     
         11 . The method as set forth in  claim 1  wherein the polishing pads are made of polyurethane or polyurethane impregnated polyester felts. 
     
     
         12 . A method for conditioning a new polishing pad in a double-side polishing apparatus having first and second platens and one or more wafer carriers, the method comprising:
 mounting the new polishing pad on the first platen or the second platen;   placing one or more sacrificial wafers in the one or more wafer carriers;   contacting a first batch of one or more sacrificial wafers with the new polishing pad while supplying a first polishing fluid to the new polishing pad in a first polishing operation;   contacting the new polishing pad with a conditioning substrate; and   contacting a second batch of one or more sacrificial wafers with the new polishing pad while supplying a second polishing fluid to the new polishing pad in a second polishing operation.   
     
     
         13 . The method as set forth in  claim 12  wherein the conditioning substrate comprises diamonds. 
     
     
         14 . The method as set forth in  claim 13  wherein the conditioning substate is part of a conditioning substrate wheel, the conditioning substate wheel being an annulus. 
     
     
         15 . The method as set forth in  claim 12  comprising contacting the new polishing pad with an annular cleaning brush in a brushing operation, the brushing operation being prior to the second polishing operation. 
     
     
         16 . The method as set forth in  claim 15  wherein the brushing operation is a second brushing operation, the method comprising contacting the new polishing pad with an annular cleaning brush in a first brushing operation, the first brushing operation being prior to the first polishing operation, the same polishing brush being used in the first brushing operation and the second brushing operation. 
     
     
         17 . The method as set forth in  claim 12  wherein the first and second polishing fluids have the same composition. 
     
     
         18 . A method for polishing product substates in a double-side polishing apparatus having first and second platens and wafer carriers, the method comprising:
 mounting new polishing pads on the first and second platens;   placing sacrificial wafers in the wafer carriers;   contacting the sacrificial wafers with the new polishing pads while supplying a first polishing fluid to the new polishing pads in a first polishing operation;   contacting the new polishing pads with a conditioning substrate;   contacting sacrificial wafers with the new polishing pads while supplying a second polishing fluid to the new polishing pads in a second polishing operation;   placing product wafers in the wafer carriers; and   contacting the product wafers with the new polishing pads while supplying a third polishing fluid to the new polishing pads in a third polishing operation.   
     
     
         19 . The method as set forth in  claim 18  wherein the conditioning substrate comprises diamonds. 
     
     
         20 . The method as set forth in  claim 18  comprising:
 contacting the new polishing pads with an annular cleaning brush in a first brushing operation, the first brushing operation being prior to the first polishing operation; and 
 contacting the new polishing pads with an annular cleaning brush in a second brushing operation, the second brushing operation being prior to the second polishing operation.