Method and system for performing chemical mechanical polishing

Abstract

A method of using a polishing system includes securing a wafer in a carrier head, the carrier head including a housing enclosing the wafer, in which the housing includes a retainer ring recess and a retainer ring positioned in the retainer ring recess, the retainer ring surrounding the wafer, in which the retainer ring includes a main body portion and a bottom portion connected to the main body portion, and a bottom surface of the bottom portion includes at least one first engraved region and a first non-engraved region adjacent to the first engraved region; pressing the wafer against a polishing pad; and moving the carrier head or the polishing pad relative to the other.

What is claimed is: 
     
         1 . A carrier head of a chemical mechanical polishing system, comprising:
 a housing including a recess;   a membrane support, wherein the housing encloses the membrane support;   a membrane secured to the membrane support; and   a retainer ring positioned in the recess of the housing, wherein the retainer ring includes a plurality of grooves and a first plurality of protrusions, wherein the plurality of grooves has a longitudinal axis extending from a perimeter of the retainer ring toward a center of the retainer ring, the first plurality of protrusions is arranged in rows and columns, and the first plurality of protrusions has a dimension different from a dimension of the plurality of grooves.   
     
     
         2 . The carrier head of  claim 1 , wherein the dimension of the first plurality of protrusions is smaller than the dimension of the plurality of grooves. 
     
     
         3 . The carrier head of  claim 1 , wherein the retainer ring further comprises:
 a vacuum hole placed between two neighbors of the plurality of grooves.   
     
     
         4 . The carrier head of  claim 1 , further comprising:
 a second plurality of protrusions spaced apart from the first plurality of protrusions, wherein the second plurality of protrusions is arranged in rows and columns, and the first plurality of protrusions and the second plurality of protrusions are placed between two neighbors of the plurality of grooves.   
     
     
         5 . The carrier head of  claim 4 , wherein the second plurality of protrusions has a dimension smaller than the dimension of the plurality of grooves. 
     
     
         6 . The carrier head of  claim 4 , wherein the retainer ring further comprises:
 a third plurality of protrusions disposed in one of the plurality of grooves, wherein the third plurality of protrusions is arranged in rows and columns.   
     
     
         7 . The carrier head of  claim 6 , wherein the third plurality of protrusions has a dimension smaller than the dimension of the plurality of grooves. 
     
     
         8 . A chemical mechanical polishing system, comprising:
 a polishing pad;   a carrier head including a retainer ring to retain a wafer proximate to the polishing pad during polishing; and   a conditioning disk placed over a top surface of the polishing pad, wherein the conditioning disk has a first engraved surface facing the top surface of the polishing pad, the first engraved surface is made of a first plurality of non-diamond protrusions, and the first plurality of non-diamond protrusions is arranged in rows and columns.   
     
     
         9 . The chemical mechanical polishing system of  claim 8 , wherein the conditioning disk further comprises:
 a plurality of vacuum holes arranged randomly.   
     
     
         10 . The chemical mechanical polishing system of  claim 8 , wherein the conditioning disk further comprises:
 a plurality of vacuum holes arranged concentrically.   
     
     
         11 . The chemical mechanical polishing system of  claim 10 , wherein the conditioning disk further comprises:
 a second engraved surface made of a second plurality of non-diamond protrusions, wherein the plurality of vacuum holes is placed between the first engraved surface and the second engraved surface.   
     
     
         12 . The chemical mechanical polishing system of  claim 11 , wherein the second plurality of non-diamond protrusions is arranged in rows and columns. 
     
     
         13 . The chemical mechanical polishing system of  claim 11 , wherein when viewed from top, the first engraved surface has a diameter less than a diameter of the conditioning disk. 
     
     
         14 . The chemical mechanical polishing system of  claim 8 , wherein the conditioning disk further comprises a plurality of non-engraved surfaces having a roughness lower than a roughness of the first engraved surface. 
     
     
         15 . The chemical mechanical polishing system of  claim 14 , wherein when viewed from top, the plurality of non-engraved surfaces each extends in a radial direction. 
     
     
         16 . The chemical mechanical polishing system of  claim 14 , wherein the conditioning disk further comprises:
 a vacuum hole disposed on one of the plurality of non-engraved surfaces.   
     
     
         17 . The chemical mechanical polishing system of  claim 14 , wherein when viewed from top, the plurality of non-engraved surfaces has a circular shape. 
     
     
         18 . The chemical mechanical polishing system of  claim 17 , wherein the conditioning disk further comprises:
 a vacuum hole disposed on one of the plurality of non-engraved surfaces.   
     
     
         19 . A chemical mechanical polishing system, comprising:
 a polishing pad; and   a carrier head securing a wafer, wherein the wafer is between the carrier head and the polishing pad, and the carrier head comprises:
 a housing including a recess; 
 a membrane support, wherein the housing encloses the membrane support; 
 a membrane secured to the membrane support; and 
 a retainer ring positioned in the recess of the housing, wherein the retainer ring includes a plurality of grooves, a plurality of bumps interleaved with the plurality of grooves, and a first plurality of protrusions protrudes from one of the plurality of grooves, wherein the first plurality of protrusions is arranged in rows and columns. 
   
     
     
         20 . The chemical mechanical polishing system of  claim 19 , wherein the first plurality of protrusions is made of a non-diamond material.