Using A Carrier Head With Shims

Abstract

A carrier head includes a base, a substrate mounting surface, a retaining ring secured to the base, and a plurality of stacked shims located between the base and the retaining ring. The retaining ring has a bottom surface for contacting a polishing pad during polishing.

1 - 10 . (canceled) 
     
     
         11 . A method of using a retaining ring, comprising:
 securing a top surface of the retaining ring to a base in a carrier head without a shim between the base and the retaining ring, wherein the top surface of the retaining ring is substantially flat from an inner diameter of the retaining ring to an outer diameter of the retaining ring;   polishing a first plurality of substrates with the carrier head, a lower surface of the retaining ring contacting a polishing surface;   removing the retaining ring from the carrier head after the lower surface of the ring has been worn by a first amount;   re-securing the retaining ring to the carrier head with a first shim between the base and the retaining ring to compensate for the first amount of wear, wherein the first shim has a same inner diameter and outer diameter as the retaining ring;   polishing a second plurality of substrates with the carrier head;   removing the retaining ring from the carrier head after the lower surface of the ring has been worn by a second amount; and   re-securing the retaining ring to the carrier head with the first shim and a second shim between the base and the retaining ring to compensate for the second amount of wear, wherein the second shim has a same inner diameter and outer diameter as the retaining ring.   
     
     
         12 . The method of  claim 11 , wherein the first amount is greater than the second amount. 
     
     
         13 . The method of  claim 12 , wherein a thickness of the first shim is greater than a thickness of the second shim. 
     
     
         14 . The method of  claim 13 , wherein the first shim is about 90 mils thick, and the second shim is about 30 mils thick. 
     
     
         15 . The method of  claim 11 , further comprising securing the retaining ring to the base with a plurality of screws that pass through the plurality of stacked shims. 
     
     
         16 . The method of  claim 11 , further comprising transporting slurry through a plurality of slurry-transport channels formed on the bottom surface of the retaining ring. 
     
     
         17 . The method of  claim 11 , wherein the first shim has a first thickness about equal to the first amount and the second shim has a second thickness about equal to the second amount. 
     
     
         18 . The method of  claim 11 , wherein the retaining ring comprises a lower portion of a first material having the bottom surface and an upper portion of a second material that is more rigid than the lower portion. 
     
     
         19 . The method of  claim 18 , wherein the first shim and the second shim are each formed of the second material. 
     
     
         20 . The method of  claim 18 , wherein the first material is PPS and the second material is stainless steel. 
     
     
         21 . The method of  claim 11 , wherein each the first shim and the second shim are formed of the same material. 
     
     
         22 . The carrier head of claim  1 , wherein each shim of the plurality of stacked shims is right angular cylindrical part. 
     
     
         23 . A method of using a retaining ring, comprising:
 securing a top surface of the retaining ring to a base in a carrier head without a shim between the base and the retaining ring, wherein the top surface of the retaining ring is substantially flat from an inner diameter of the retaining ring to an outer diameter of the retaining ring;   polishing a first plurality of substrates with the carrier head, a lower surface of the retaining ring contacting a polishing surface;   removing the retaining ring from the carrier head after the lower surface of the ring has been worn by a first amount;   re-securing the retaining ring to the carrier head with a first shim between the base and the retaining ring to compensate for the first amount of wear, wherein the first shim has a same inner diameter and outer diameter as the retaining ring; and   polishing a second plurality of substrates with the carrier head.