Chemical mechanical planarization (cmp) pads with integrated wear indicator

Abstract

A polishing pad that includes one or more wear indicators, a chemical mechanical planarization (CMP) apparatus that includes the polishing pad, and associated methods. The polishing pad may include a body configured to engage with a platen of the CMP apparatus. The polishing pad may further include a plurality of grooves formed on a top surface of the body. The plurality of grooves are sized and shaped to facilitate uniform distribution of a slurry across the top surface of the polishing pad during operation. The polishing pad further includes a wear indicator positioned within one of the grooves that includes a top surface having a height that is lower than a height of the groove in the body of the polishing pad. The wear indicator may be configured to allow determination of different levels of wear of the polishing pad.

1 . A polishing pad, comprising:
 a body configured to engage with a platen of a chemical mechanical planarization (CMP) apparatus;   a plurality of grooves formed on a top surface of the body, the plurality of grooves sized and shaped to facilitate uniform distribution of a slurry across the top surface of the polishing pad during operation; and   a wear indicator positioned within one of the grooves, the wear indicator comprising a top surface having a height that is lower than a height of the groove in the body of the polishing pad.   
     
     
         2 . The polishing pad of  claim 1 , wherein the wear indicator has a color different from a color of the body of the polishing pad. 
     
     
         3 . The polishing pad of  claim 1 , wherein the wear indicator has a height that is between 10 percent and 90 percent of the height of the groove in the body of the polishing pad. 
     
     
         4 . The polishing pad of  claim 1 , wherein the wear indicator has a width that is between 50 percent and 100 percent of a width of the groove in the body of the polishing pad. 
     
     
         5 . The polishing pad of  claim 1 , further comprising an opening between the top surface of the wear indicator and a bottom surface of the groove that allows passage of the slurry through the opening in the groove during operation. 
     
     
         6 . The polishing pad of  claim 1 , wherein the wear indicator includes a plurality of wear indicators, each of the wear indicators having a top surface that is a different height than the other top surfaces of the wear indicators. 
     
     
         7 . The polishing pad of  claim 6 , wherein each of the top surfaces of the plurality of wear indicators has a different color than the top surfaces of the other wear indicators. 
     
     
         8 . The polishing pad of  claim 6 , wherein the plurality of indicators are positioned adjacent to each other. 
     
     
         9 . The polishing pad of  claim 1 , wherein the wear indicator include a plurality of wear indicators arranged in the plurality of grooves in a linear pattern, in a radial pattern, or in a star-shaped pattern. 
     
     
         10 . The polishing pad of  claim 1 , wherein the wear indicator has a cuboid shape, a triangular shape, a cylindrical shape, a cone shape, or a dome shape. 
     
     
         11 . The polishing pad of  claim 1 , wherein the wear indicator is formed during molding of the polishing pad or machining of the plurality of grooves. 
     
     
         12 . The polishing pad of  claim 1 , wherein the wear indicator is affixed to the one of the plurality of grooves in the body of the polishing pad. 
     
     
         13 . The polishing pad of  claim 1 , wherein the wear indicator is made from the same material as the body of the polishing pad. 
     
     
         14 . The polishing pad of  claim 1 , wherein the wear indicator comprises a plurality of stacked portions, each portion having a different color or material from the other portions. 
     
     
         15 . The polishing pad of  claim 1 , further comprising:
 a sensor configured to sense a condition wherein, after use of the polishing pad, the top surface of the polishing pad is substantially the same height as the height of the wear indicator.   
     
     
         16 . A chemical mechanical planarization (CMP) apparatus, comprising:
 a platen;   a polishing pad mounted on the platen to be rotated by the platen during operation, wherein the polishing pad comprises:
 a body; 
 a plurality of grooves formed on a top surface of the body, the plurality of grooves sized and shaped to facilitate uniform distribution of a slurry across the top surface of the polishing pad during operation; and 
 a wear indicator positioned within one of the grooves, the wear indicator comprising a top surface having a height that is lower than a height of the groove in the body of the polishing pad; 
   a slurry feed system positioned above the polishing pad configured to dispense a slurry onto the surface of the polishing pad;   a carrier device configured to hold and press a semiconductor wafer against the polishing pad; and   at least one sensor configured to detect a condition wherein, after use of the polishing pad, the height of the top surface of the body of the polishing pad is substantially the same as the height of the top surface of the wear indicator.   
     
     
         17 . The CMP apparatus of  claim 16 , wherein the wear indicator has a color different from a color of the body of the polishing pad. 
     
     
         18 . The CMP apparatus of  claim 16 , further comprising an opening between the top surface of the wear indicator and a bottom surface of the groove that allows passage of the slurry through the opening in the groove during operation. 
     
     
         19 . The CMP apparatus of  claim 16 , wherein the wear indicator include a plurality of wear indicators arranged in the plurality of grooves in a linear pattern, in a radial pattern, or in a star-shaped pattern. 
     
     
         20 . A method of operating a chemical mechanical planarization (CMP) apparatus, comprising:
 providing a CMP apparatus comprising a platen, a polishing pad mounted on the platen, a slurry feed system, and a carrier device, the polishing pad comprising:
 a body configured to engage with the platen; 
 a plurality of grooves formed on a top surface of the body, the plurality of grooves sized and shaped to facilitate uniform distribution of a slurry from the slurry feed system across the top surface of the polishing pad during operation; and 
 a wear indicator positioned within one of the grooves, the wear indicator comprising a top surface having a height that is lower than a height of the groove in the body of the polishing pad; 
   operating the CMP apparatus over a time period;   monitoring a condition of the polishing pad over time using at least one observer by determining whether the height of the top surface of the polishing pad is substantially the same as the height of the top surface of the wear indicator; and   responsive to determining that the height of the top surface of the polishing pad is substantially the same as the height of the top surface of the wear indicator, generating a signal that indicates that the polishing pad is worn and should be replaced.