Workpiece proximity etching method and apparatus

Abstract

The present invention relates to methods and apparatus for plating a conductive material on a semiconductor substrate by rotating pad or blade type objects in close proximity to the substrate, thereby eliminating/reducing dishing and voids. This is achieved by providing pad or blade type objects mounted on cylindrical anodes or rollers and applying the conductive material to the substrate using the electrolyte solution disposed on or through the pads, or on the blades. In one embodiment of the invention, the pad or blade type objects are mounted on the cylindrical anodes and rotated about a first axis while the workpiece may be stationary or rotate about a second axis, and metal from the electrolyte solution is deposited on the workpiece when a potential difference is applied between the workpiece and the anode. In another embodiment of the present invention, the plating apparatus includes an anode plate spaced apart from the cathode workpiece. Upon application of power to the anode plate and the cathode workpiece, the electrolyte solution disposed in the plating apparatus is used to deposit the conductive material on the workpiece surface using cylindrical rollers having the pad or blade type objects.

1 . A method of etching a conductive material on a surface of a workpiece, comprising the steps of: 
 applying a voltage between an electrode and a workpiece;    rotating a plurality of rollers having pad or blade strips in a circular direction; and    continuously applying an etching solution to the surface of the workpiece as the plurality of rollers are rotated in the circular direction.    
     
     
         2 . The method of  claim 1 , wherein the plurality of rollers comprise cylindrical rollers.  
     
     
         3 . The method of  claim 2 , wherein the cylindrical rollers comprise hollow cylinders.  
     
     
         4 . The method of  claim 3 , wherein the cylindrical rollers comprise diameters between 10 to 30 mm.  
     
     
         5 . The method of  claim 1 , wherein a first predetermined number of the plurality of rollers are rotated in a clockwise direction and a second predetermined number of the plurality of rollers are rotated in a counter-clockwise direction.  
     
     
         6 . The method of  claim 1 , wherein the pad or blade strips are attached to the outer surfaces of the plurality of rollers.  
     
     
         7 . A method of etching a conductive material on a surface of a workpiece, comprising the steps of: 
 applying a voltage between an electrode and a plurality of rollers having conductive pads or blade strips, wherein the pads or blade strips make contact with the workpiece;    rotating a plurality of rollers having pad or blade strips in a circular direction; and    continuously applying an etching solution to the surface of the workpiece as the plurality of rollers are rotated in the circular direction.    
     
     
         8 . The method of  claim 7 , wherein the plurality of rollers comprise cylindrical rollers.  
     
     
         9 . The method of  claim 8 , wherein the cylindrical rollers comprise hollow cylinders.  
     
     
         10 . The method of  claim 9 , wherein the cylindrical rollers comprise diameters between 10 to 30 mm.  
     
     
         11 . The method of  claim 7 , wherein a first predetermined number of the plurality of rollers are rotated in a clockwise direction and a second predetermined number of the plurality of rollers are rotated in a counter-clockwise direction.  
     
     
         12 . The method of  claim 7 , wherein the pad or blade strips are attached to the outer surfaces of the plurality of rollers.  
     
     
         13 . A method of removing a conductive layer from a surface of a workpiece, comprising the steps: 
 contacting the surface of the workpiece with a conductive material;    wetting the surface of the workpiece and an electrode using a solution; and    applying a voltage between the electrode and the conductive material to remove the conductive layer from the surface of the workpiece.    
     
     
         14 . The method of  claim 13 , wherein the conductive material is a conductive pad.  
     
     
         15 . The method of  claim 14 , wherein the conductive material includes strips of the conductive pad.  
     
     
         16 . The method of  claim 14  further comprising a plurality of rollers having a plurality of the conductive pads attached to an outer surface of each of the plurality of rollers.  
     
     
         17 . The method of  claim 13 , wherein the step of applying the voltage includes pulsing the voltage between the electrode and the surface of the workpiece.  
     
     
         18 . The method of  claim 13 , wherein the step of contacting the surface includes maintaining relative motion between the surface of the workpiece and the conductive material.  
     
     
         19 . The method of  claim 18 , wherein the step of maintaining relative motion includes rotating a plurality of rollers having a plurality of the conductive material.  
     
     
         20 . The method of  claim 19 , wherein the step of applying the voltage includes electrically contacting at least one of the plurality of rollers.  
     
     
         21 . The method of  claim 19 , wherein a first set of the plurality of rollers rotates in a clockwise direction and a second set of the plurality of rollers rotates in a counter-clockwise direction.  
     
     
         22 . The method of  claim 19 , wherein the plurality of rollers includes a plurality of conductive blade strips attached to an outer surface of each of the plurality of rollers.  
     
     
         23 . An integrated circuit manufactured according to the method of  claim 13.