Methods and Systems for Retaining Grinding Efficiency During Backgrinding of Through-Via Substrates

Abstract

Methods and systems for retaining grinding efficiency during a backgrinding process such as, for example, backgrinding of a through-via substrate such as an embedded through silicon via wafer. A grinding fluid may include a chemical agent that is configured to remove accumulated materials from the grinding wheel.

1 . A method for retaining grinding efficiency during a backgrinding process, comprising:
 backgrinding a substrate using a grinding wheel that comprises an abrasive material configured to remove a substrate material from the substrate during the backgrinding process;   using a grinding fluid during the backgrinding of the substrate, the grinding fluid comprising a chemical agent that is configured to remove an accumulated portion of the substrate material from the abrasive material.   
     
     
         2 . The method of  claim 1 , the chemical agent being configured to remove the accumulated portion from the abrasive material by chelating the accumulated portion. 
     
     
         3 . The method of  claim 2 , the chemical agent comprising a citrate. 
     
     
         4 . The method of  claim 2 , the chemical agent comprising a succinate. 
     
     
         5 . The method of  claim 2 , the chemical agent comprising a benzotriazole. 
     
     
         6 . The method of  claim 2 , the grinding fluid further comprising a second chemical agent that is configured to etch the accumulated portion. 
     
     
         7 . The method of  claim 2 , further comprising adjusting the pH of the grinding fluid to facilitate the chelating of the accumulated portion. 
     
     
         8 . The method of  claim 1 , further comprising cleaning the grinding wheel prior to backgrinding the substrate using a pre-grinding chemical agent, the pre-grinding chemical agent being configured to remove a previously accumulated portion of a previous substrate material from the abrasive material. 
     
     
         9 . The method of  claim 8 , the pre-grinding chemical agent being configured to remove the previously accumulated portion from the abrasive material by chelating the previously accumulated portion. 
     
     
         10 . The method of  claim 9 , the pre-grinding chemical agent comprising a citrate 
     
     
         11 . The method of  claim 9 , the pre-grinding chemical agent comprising a succinate 
     
     
         12 . The method of  claim 9 , the pre-grinding chemical agent comprising a benzotriazole. 
     
     
         13 . The method of  claim 9 , where cleaning the grinding wheel prior to backgrinding the substrate further comprises using sonic agitation. 
     
     
         14 . The method of  claim 9 , where cleaning the grinding wheel prior to backgrinding the substrate further comprises using a contact-cleaning brush. 
     
     
         15 . A system for performing a backgrinding process, the system comprising:
 a pedestal;   a grinding wheel configured to backgrind a substrate supported by the pedestal, the grinding wheel comprising an abrasive material configured to remove a substrate material from the substrate during the backgrinding process; and   a fluid source configured to deliver a grinding fluid to the substrate while the grinding wheel backgrinds the substrate, the grinding fluid comprising a chemical agent that is configured to remove an accumulated portion of the substrate material from the abrasive material by chelating the accumulated portion.   
     
     
         16 . The system of  claim 15 , the chemical agent comprising a citrate. 
     
     
         17 . The system of  claim 15 , the chemical agent comprising a succinate. 
     
     
         18 . The system of  claim 15 , the chemical agent comprising a benzotriazole. 
     
     
         19 . The system of  claim 15 , further comprising a cleaning extension configured to deliver a cleaning fluid to the grinding wheel, the cleaning fluid comprising a pre-grinding chemical agent that is configured to remove a previously accumulated portion of a previous substrate material from the abrasive material by chelating the previously accumulated portion. 
     
     
         20 . The system of  claim 19 , the pre-grinding chemical agent comprising a citrate. 
     
     
         21 . The system of  claim 19 , the pre-grinding chemical agent comprising a succinate. 
     
     
         22 . The system of  claim 19 , the pre-grinding chemical agent comprising a benzotriazole.