Enhanced silicon grind using chemical additives in fluid during grinding process

Abstract

A method and apparatus for grinding a surface of a substrate is presented. The method includes positioning a substrate proximate a grinding surface using a carrier head, providing a pressure on the substrate to press an unpolished surface of the substrate to the grinding surface, flowing a grinding fluid onto the unpolished surface, the grinding fluid comprising a pH adjuster, viscosity additives, a surfactant, or combinations thereof, and grinding the unpolished surface using the grinding surface to create a polished surface on the substrate.

What is claimed is: 
     
         1 . A polishing station, comprising:
 a platen;   a grinding pad having a grinding surface and disposed on the platen;   a supply-rinse arm configured to flow a grinding fluid, the grinding fluid comprising a pH adjuster, viscosity additives, a surfactant, or combinations thereof; and   a carrier head configured to hold a substrate.   
     
     
         2 . The polishing station of  claim 1 , further comprising a controller, wherein the controller is configured to cause the polishing station to:
 position a substrate proximate the grinding surface using the carrier head;   provide a pressure on the substrate to press an unpolished surface of the substrate to the grinding surface;   flow a grinding fluid onto the unpolished surface using the supply-rinse arm; and   grinding the unpolished surface using the grinding surface of the grinding pad to create a polished surface on the substrate.   
     
     
         3 . The polishing station of  claim 1 , wherein the grinding fluid has a pH level of about 7 to about 12. 
     
     
         4 . The polishing station of  claim 1 , wherein the grinding fluid is configured to create a substrate particle suspension using a surfactant and substrate particles released from an unpolished surface of the substrate. 
     
     
         5 . The polishing station of  claim 4 , wherein the surfactant forms a micelle layer on outer surfaces of the substrate particles. 
     
     
         6 . The polishing station of  claim 4 , wherein the substrate particle suspension exerts a grinding force on an unpolished surface of the substrate. 
     
     
         7 . The polishing station of  claim 1 , wherein the grinding pad comprises abrasive additives, the abrasive additives including diamond abrasive particles. 
     
     
         8 . A grinding system, comprising:
 a carrier head configured to hold a substrate;   a grinding station comprising:
 a grinding pad having a grinding surface; and 
 a fluid bearing surface having openings configured to flow a grinding fluid, the grinding fluid comprising a pH adjuster, viscosity additives, a surfactant, or combinations thereof. 
   
     
     
         9 . The grinding system of  claim 8 , further comprising a controller, wherein the controller is configured to cause the grinding system to:
 position a substrate proximate the grinding surface using the carrier head;   provide a pressure on the substrate to press an unpolished surface of the substrate to the grinding surface;   flow a grinding fluid onto the unpolished surface using the openings of the fluid bearing surface; and   grind, using the grinding surface, the unpolished surface to create a polished surface on the substrate.   
     
     
         10 . The grinding system of  claim 8 , wherein the grinding fluid has a pH level of about 7 to about 12. 
     
     
         11 . The grinding system of  claim 8 , wherein the grinding fluid is configured to create a substrate particle suspension using a surfactant and substrate particles released from an unpolished surface of the substrate. 
     
     
         12 . The grinding system of  claim 11 , wherein the surfactant forms a micelle layer on outer surfaces of the substrate particles. 
     
     
         13 . The grinding system of  claim 11 , wherein the substrate particle suspension exerts a grinding force on an unpolished surface of the substrate. 
     
     
         14 . The grinding system of  claim 8 , wherein the grinding surface of the grinding pad comprises diamond abrasives. 
     
     
         15 . A method of grinding a substrate, comprising:
 positioning a substrate proximate a grinding surface using a carrier head;   providing a pressure on the substrate to press an unpolished surface of the substrate to the grinding surface;   flowing a grinding fluid onto the unpolished surface, the grinding fluid comprising a pH adjuster, viscosity additives, a surfactant, or combinations thereof; and   grinding the unpolished surface using the grinding surface to create a polished surface on the substrate.   
     
     
         16 . The method of  claim 15 , wherein the grinding surface comprises diamond abrasives. 
     
     
         17 . The method of  claim 15 , wherein the grinding fluid has a pH level of about 7 to about 12. 
     
     
         18 . The method of  claim 15 , further comprising:
 after flowing the grinding fluid, generating a substrate particle suspension using a surfactant and substrate particles released from the unpolished surface during grinding.   
     
     
         19 . The method of  claim 18 , wherein the surfactant forms a micelle layer on outer surfaces of the substrate particles. 
     
     
         20 . The method of  claim 18 , wherein the substrate particle suspension exerts a grinding force on the unpolished surface.