Grid relief in CMP polishing pad to accurately measure pad wear, pad profile and pad wear profile

Abstract

A method and apparatus for measuring wear of the thickness of a chemical mechanical polishing pad are provided. The apparatus includes a chemical mechanical polishing pad having a plurality of reliefs in a main polishing surface for determining wear of the pad. In one aspect, the pad reliefs comprise through-holes in the pad or extend partially through a thickness of the pad. The method for measuring wear of the thickness of a chemical mechanical polishing pad includes providing a plurality of reliefs in a main polishing surface of the pad and measuring a distance from the main polishing surface to a bottom surface of each of a plurality of the reliefs.

1 . A chemical mechanical polishing pad having a plurality of reliefs in a main polishing surface for determining wear of the pad, wherein the reliefs are disposed in a predetermined pattern such that the wear of the pad is determinable as a function of pad radius.  
     
     
         2 . The pad of  claim 1 , wherein the reliefs extend partially through a thickness of the pad.  
     
     
         3 . The pad of  claim 2 , wherein the pad is round.  
     
     
         4 . The pad of  claim 3 , wherein the plurality of reliefs in have a rectangular, square, triangular or round shape.  
     
     
         5 . A chemical mechanical polishing pad having a plurality of reliefs in a main polishing surface for determining wear of the pad, wherein the reliefs comprise through-holes in the pad.  
     
     
         6 . The pad of  claim 5 , wherein the reliefs are distributed in a predetermined pattern to enable monitoring the pad wear as a function of pad radius.  
     
     
         7 . The pad of  claim 6 , wherein the predetermined pattern is configured to enable monitoring of the pad wear to discern whether two or more regions of the pad are wearing at different rates.  
     
     
         8 . The pad of  claim 6 , wherein at least some of the reliefs are individually monitored to establish a wear pattern specific to a pattern of at least some of the reliefs.  
     
     
         9 . The pad of  claim 6 , wherein the pad is round.  
     
     
         10 . The pad of  claim 9 , wherein the plurality of reliefs in have a rectangular, square, triangular or round shape.  
     
     
         11 . A chemical mechanical polishing pad having a plurality of reliefs disposed in a predetermined pattern thereon, wherein the predetermined pattern is configured to indicate the wear of at least one region of the pad with respect to the pad radius.  
     
     
         12 . The pad of  claim 11 , wherein the predetermined pattern is configured to enable monitoring of the pad wear to discern whether two or more regions of the pad are wearing at different rates.  
     
     
         13 . The pad of  claim 11 , wherein the predetermined pattern is selected from inline, spiral, non-symmetrical pseudo-random, and combinations thereof.  
     
     
         14 . The pad of  claim 13 , wherein the pad is round.  
     
     
         15 . The pad of  claim 14 , wherein the plurality of reliefs in have a rectangular, square, triangular or round shape.  
     
     
         16 . A chemical mechanical polishing pad having a plurality of reliefs in a main polishing surface for determining wear of the pad, wherein the reliefs have a rectangular, square, triangular or round shape.  
     
     
         17 . The pad of  claim 16 , wherein the pad is round.  
     
     
         18 . A chemical mechanical polishing pad having a plurality of reliefs in a main polishing surface for determining wear of the pad, wherein the reliefs comprise through-holes in the pad or extend partially through a thickness of the pad.  
     
     
         19 . The pad of  claim 18 , wherein the pad is round.  
     
     
         20 . The pad of  claim 19 , wherein the plurality of reliefs in have a rectangular, square, triangular or round shape.