Polishing pad conditioning system and method of using

Abstract

A method of conditioning a polishing pad includes conditioning the polishing pad using a conditioner. The method includes detecting a roughness of the polishing pad following the conditioning. The method further includes tracking a number of iterations of the conditioning of the polishing pad. The method further includes outputting a signal for replacing the polishing pad in response to the number of iterations reaching an iteration limit. The method further includes repeating the conditioning in response to the detected roughness of the polishing pad being outside of a threshold roughness range and the number of iterations failing to reach the iteration limit.

What is claimed is: 
     
         1 . A method of conditioning a polishing pad comprising:
 conditioning the polishing pad using a conditioner;   detecting a roughness of the polishing pad following the conditioning;   tracking a number of iterations of the conditioning of the polishing pad;   outputting a signal for replacing the polishing pad in response to the number of iterations reaching an iteration limit; and   repeating the conditioning in response to the detected roughness of the polishing pad being outside of a threshold roughness range and the number of iterations failing to reach the iteration limit.   
     
     
         2 . The method of  claim 1 , further comprising beginning a chemical mechanical polishing (CMP) process. 
     
     
         3 . The method of  claim 2 , further comprising stopping the CMP process in response to the number of iterations reaching the iteration limit. 
     
     
         4 . The method of  claim 1 , wherein conditioning the polishing pad comprises rotating the conditioner relative to the polishing pad. 
     
     
         5 . The method of  claim 1 , wherein conditioning the polishing pad comprises translating the conditioner across the polishing pad. 
     
     
         6 . The method of  claim 1 , wherein detecting the roughness of the polishing pad comprises detecting the roughness of the polishing pad using a plurality of sensors, wherein each sensor of the plurality of sensors is at a different location relative to the polishing pad. 
     
     
         7 . The method of  claim 1 , wherein detecting the roughness of the polishing pad comprises detecting the roughness of the polishing pad using visible light and infrared light. 
     
     
         8 . The method of  claim 1 , wherein detecting the roughness of the polishing pad comprises detecting the roughness of the polishing pad at a plurality of locations on the polishing pad. 
     
     
         9 . The method of  claim 1 , wherein the iteration limit ranges from 3 to 5. 
     
     
         10 . A method of conditioning a polishing pad comprising:
 detecting a roughness of the polishing pad;   tracking a number of iterations of conditioning of the polishing pad;   determining whether the detected roughness satisfies a roughness threshold;   determining whether the number of iterations is equal to or greater than an iteration limit in response to determining that the detected roughness fails to satisfy the roughness threshold; and   outputting a signal for replacing the polishing pad in response to the number of iterations being equal to or greater than the iteration limit and the detected roughness failing to satisfy the roughness threshold.   
     
     
         11 . The method of  claim 10 , further comprising performing a chemical mechanical polishing (CMP) process in response to the detected roughness satisfying the roughness threshold. 
     
     
         12 . The method of  claim 11 , wherein performing the CMP process comprises performing the CMP process regardless of the number of iterations. 
     
     
         13 . The method of  claim 11 , further comprising stopping the CMP process in response to the number of iterations being equal to or greater than the iteration limit and the detected roughness failing to satisfy the roughness threshold. 
     
     
         16 . The method of  claim 10 , further comprising conditioning the polishing pad using a conditioner. 
     
     
         17 . The method of  claim 16 , further comprising repeating the conditioning in response to the detected roughness of the polishing pad being failing to satisfy the roughness threshold roughness and the number of iterations being less than the iteration limit. 
     
     
         18 . A system for controlling a polishing pad, comprising:
 a non-transitory computer readable medium configured to store instructions thereon; and   a processor connected to the non-transitory computer readable medium, wherein the processor is configured to execute the instructions for:
 detecting a roughness of the polishing pad; 
 tracking a number of iterations of conditioning of the polishing pad; 
 determining whether the detected roughness satisfies a roughness threshold; 
 determining whether the number of iterations is equal to or greater than an iteration limit in response to determining that the detected roughness fails to satisfy the roughness threshold; and 
 outputting a signal for replacing the polishing pad in response to the number of iterations being equal to or greater than the iteration limit and the detected roughness failing to satisfy the roughness threshold. 
   
     
     
         19 . The system of  claim 18 , further comprising a plurality of sensors, wherein the processor is configured to execute the instructions for detecting the roughness of the polishing pad based on an output of each of the plurality of sensors. 
     
     
         20 . The system of  claim 19 , wherein a first sensor of the plurality of sensors is configured to detect light having a first wavelength, and a second sensor of the plurality of sensors is configured to detect light having a second wavelength different from the first wavelength.