Edge and bevel cleaning process and system

Abstract

A method of removing unwanted edge copper from an edge region of a wafer is provided. The method is applied subsequent to an electrochemical process to deposit a copper layer on a surface of a wafer. The edge region, which has the unwanted edge copper, includes a front edge surface, a back edge surface and a bevel. During the removal as the wafer is rotated, a stream of etchant solution from a front edge nozzle is delivered to the front edge surface of the wafer while another stream is delivered to the back edge surface from a back edge nozzle. Rotational motion of the wafer directs the etchant, which is delivered by the front and back edge nozzles, to the bevel and thereby causing removal of the unwanted copper from the edge region of the wafer.

1 . A method of removing conductive material from an edge region of a workpiece subsequent to an electrochemical process, wherein the edge region comprises a front edge surface, a back edge surface and a bevel, the method comprising the steps of: 
 rotating the workpiece;    directing a first etchant flow onto the back edge surface of the workpiece; and    directing a second etchant flow onto the front edge surface of the workpiece, wherein rotating the workpiece results in outwardly directing the etchant, which is delivered by the first and the second etchant flows, to the bevel and thereby causing removal of the conductive material from the edge region of the workpiece.    
     
     
         2 . The method of  claim 1 , wherein the steps of directing the first etchant flow and the second etchant flow are performed simultaneously.  
     
     
         3 . The method of  claim 1 , wherein the first etchant flow is directed from at least one nozzle directed to the back edge surface of the workpiece.  
     
     
         4 . The method of  claim 1 , wherein the second etchant flow is directed from at least one other nozzle directed to the front edge surface of the workpiece.  
     
     
         5 . The method of  claim 1  further including the step of spraying a cleaning solution onto a front surface of the workpiece, wherein the step of spraying takes place prior to the step of directing the first and the etchant flows.  
     
     
         6 . The method of  claim 5  further including the step of spin drying the workpiece after the step of spraying.  
     
     
         7 . The method of  claim 1 , wherein a flow rate of the first etchant flow is different than a flow rate of the second etchant flow.  
     
     
         8 . The method of  claim 1 , wherein a flow rate of the first etchant flow is the same as a flow rate of the second etchant flow.  
     
     
         9 . An edge copper removal system for removing conductive material from an edge region of a workpiece subsequent to an electrochemical process as the workpiece rotated, wherein the edge region comprises a front edge surface, a back edge surface, and a bevel comprising: 
 at least one nozzle for directing a first etchant flow onto the back edge surface of the workpiece;    at least one other nozzle for directing a second etchant flow onto the front surface edge of the workpiece.    
     
     
         10 . The system of  claim 9 , wherein the at least one nozzle and the at least one other nozzle receive etchant from the same etchant supply tank.  
     
     
         11 . The system of  claim 9 , wherein the at least one nozzle and the at least one other nozzle receive etchant from different etchant supply tanks.  
     
     
         12 . The system of  claim 9 , wherein the at least one nozzle and the at least one other nozzle are integral parts of an edge copper removal device.  
     
     
         13 . The system of  claim 9 , wherein a flow rate of the first etchant flow is different than a flow rate of the second etchant flow.  
     
     
         14 . The system of  claim 9 , wherein a flow rate of the first etchant flow is the same as a flow rate of the second etchant flow.