Chemically modified chemical mechanical polishing pad, process of making a modified chemical mechanical polishing pad and method of chemical mechanical polishing

Abstract

A method of CMP of a substrate surface includes providing a polishing pad having a polishing layer, that may be substantially free of abrasive particles, with a functional group chemically bonded (covalent or ionic) to the polishing layer. The functional group acts as an activator or catalyst for a compound of a polishing slurry to exhibit a higher material removal rate for removing selected portions of the surface of the substrate than exhibited in CMP of a substantially identical substrate in the presence of a substantially identical polishing slurry and a polishing pad wherein the substantially identical polishing layer does not have the functional group. The functional group may be derived from a compound comprising a polyamine, a polyelectrolyte, and/or an amino acid. A method of making the CMP pad and the CMP pad formed thereby is also disclosed.

1 . A method of chemical mechanical polishing of a surface of a substrate to remove selected portions thereof comprising: 
 A) Providing a polishing pad having a polishing layer which is substantially free of abrasive particles and having a functional group chemically bonded to the polishing layer;    B) Providing a polishing slurry in contact with at least a portion of the polishing layer of the polishing pad and in contact with at least a portion of the surface of the substrate;    C) Maintaining at least a portion of the surface of the substrate in sliding frictional contact with at least a portion of the polishing layer of the substrate in the presence of the polishing slurry until the selected portions of the surface of the substrate are removed, wherein the functional group acts as an activator or catalyst for a compound of the polishing slurry to exhibit a higher material removal rate for removing selected portions of the surface of the substrate than exhibited in chemical mechanical polishing of a substantially identical substrate in the presence of a substantially identical polishing slurry and a polishing pad wherein the substantially identical polishing layer does not have the functional group.    
     
     
         2 . The method of chemical mechanical polishing of  claim 1  wherein the functional group is derived from a compound comprising a polyamine, a polyelectrolyte, and/or an amino acid.  
     
     
         3 . The method of  claim 1  wherein the polishing slurry includes a persulfate or a polyelectrolyte and wherein the surface of the substrate includes copper.  
     
     
         4 . The method of mechanical polishing of  claim 1  wherein the polishing layer comprises a porous polyurethane, wherein the functional group is derived from ethylene diamine, and wherein the polishing slurry comprises potassium persulfate.  
     
     
         5 . The method of mechanical polishing of  claim 1  wherein the polishing layer comprises a porous polyurethane, and wherein the functional group is derived from polyethyleneimine.  
     
     
         6 . A chemical mechanical polishing pad for polishing a surface of a substrate to remove selected portions thereof, the pad comprising: 
 A) A polishing layer configured to contact the surface of a substrate in the presence of a polishing slurry to remove selected portions thereof; and    B) A polyamine chemically bonded to the polishing layer.    
     
     
         7 . The chemical mechanical polishing pad of  claim 6  wherein the polyamine comprises an aliphatic or aromatic diamine.  
     
     
         8 . The chemical mechanical polishing pad of  claim 6  wherein the polyamine comprises an alkylene diamine.  
     
     
         9 . The chemical mechanical polishing pad of  claim 6  wherein the polyamine comprises ethylene diamine.  
     
     
         10 . The chemical mechanical polishing pad of  claim 9  wherein the polishing layer comprises a porous polyurethane and the polishing layer is substantially free of abrasive particles.  
     
     
         11 . A chemical mechanical polishing pad and slurry for polishing a surface of a substrate to remove selected portions thereof, the pad and slurry comprising: 
 A) A polishing slurry configured to contact at least a portion of the pad and to contact at least a portion of the surface of the substrate during polishing;    B) A polishing layer of the pad configured to contact the surface of a substrate in the presence of the polishing slurry to remove selected portions thereof, wherein the polishing layer of the pad is substantially free of abrasive particles; and    C) A functional group chemically bonded to the polishing layer of the pad wherein the functional group acts as an activator or catalyst for a compound in the polishing slurry to exhibit a higher material removal rate for removing selected portions of the surface of the substrate than exhibited in chemical mechanical polishing of a substantially identical substrate in the presence of a substantially identical polishing slurry and a polishing pad wherein the substantially identical polishing layer does not have the functional group.    
     
     
         12 . The chemical mechanical polishing pad and slurry of  claim 11  wherein the functional group is derived from a compound comprising a polyamine, a polyelectrolyte, and/or an amino acid.  
     
     
         13 . The chemical mechanical polishing pad and slurry of  claim 11  wherein the polishing layer comprises a porous polyurethane, wherein the functional group is derived from ethylene diamine, and wherein the polishing slurry includes potassium persulfate.  
     
     
         14 . The chemical mechanical polishing pad and slurry of  claim 11  wherein the polishing layer comprises a porous polyurethane, and wherein the functional group is derived from polyethyleneimine.  
     
     
         15 . The chemical mechanical polishing pad and slurry of  claim 11  wherein the polishing layer comprises a porous polyurethane, and wherein the functional group is derived from an amino acid.  
     
     
         16 . The chemical mechanical polishing pad and slurry of  claim 11  wherein the polishing layer comprises a porous polyurethane, and wherein the slurry includes a polyacrylate.  
     
     
         17 . A method of modifying a chemical mechanical polishing pad adapted for polishing a surface of a substrate in the presence of a polishing slurry to remove selected portions thereof, wherein the pad has a polishing layer configured to contact the surface of the substrate in the presence of the polishing slurry to remove selected portions thereof, the method comprising contacting the polishing layer with a solution containing a compound having a functional group for a period of time sufficient for the compound to chemically bond with the polishing layer, wherein the functional group acts as an activator or catalyst for a compound in the polishing slurry to exhibit a higher material removal rate for removing selected portions of the surface of the substrate than exhibited in chemical mechanical polishing of a substantially identical substrate in the presence of a substantially identical polishing slurry and a polishing pad wherein the substantially identical polishing layer does not have the functional group.  
     
     
         18 . The method of  claim 17  wherein the step of contacting the polishing layer with a solution containing compound having a functional group includes a preliminary step of contacting the polishing pad with a solution comprising oxalyl chloride for a period of time sufficient to have a —C(Cl)═O group bonded to the polishing layer.  
     
     
         19 . The process of modifying a chemical mechanical polishing pad of  claim 18  wherein the polishing layer is substantially free of abrasive particles and wherein the functional group is derived from a compound comprising a polyamine, a polyelectrolyte, and/or an amino acid.  
     
     
         20 . The product made by the method of  claim 17.