Method for processing a semiconductor wafer

Abstract

An apparatus for processing a semiconductor wafer or similar article includes a reactor having a processing chamber formed by upper and lower rotors. The wafer is supported between the rotors. The rotors are rotated by a spin motor. A processing fluid is introduced onto the top or bottom surface of the wafer, or onto both surfaces, at a central location. The fluid flows outwardly uniformly and in all directions. A wafer support automatically lifts the wafer, so that it can be removed from the reactor by a robot, when the rotors separate from each other after processing.

1 . A method for processing a workpiece comprising the steps of: 
 spinning the workpiece;    directing a process liquid to a first side of the workpiece;    with the process liquid moving radially outwardly via centrifugal force to contact toward the edge of the workpiece, moving over the edge of the workpiece, and contacting only an outer margin area on the second side of the workpiece; and    excluding the process liquid from a central area, within the outer margin area, of the second side of the workpiece.    
   
   
       2 . The method of  claim 1  where the workpiece is round and has a circular edge, and the outer margin area on the second side of the workpiece extends from 1-5 mm inwardly from the edge of the workpiece.  
   
   
       3 . The method of  claim 1  where the spinning is performed about vertical axis.  
   
   
       4 . The method of  claim 1  further comprising the step of introducing a purge gas to the second side of the workpiece, to help exclude the process liquid from the central area of the second side of the workpiece.  
   
   
       5 . The method of  claim 1  further comprising the step of holding the spin speed constant for selected amount of time necessary for the process liquid to remove an unwanted layer of material from the outer margin on the second side of the workpiece.  
   
   
       6 . The method of  claim 1  further including the step of applying a second liquid to the second side of the workpiece adjacent a center area of the workpiece and moving the second liquid radially outwardly over the second side via centrifugal force.  
   
   
       7 . The method of  claim 1  wherein the process liquid comprises an etchant.  
   
   
       8 . A metallization process used to form a microelectronic component and/or interconnect structures on a semiconductor wafer, comprising the steps of: 
 applying a barrier layer onto the wafer;    applying a thin film layer over at least a portion of the barrier layer;    electroplating of a metal layer over at least a portion of the thin film layer;    flowing an etchant, capable of etching the metal layer, and the thin film layer, onto the first side of the wafer, the edge of the wafer, and over only an outer margin of the second side of the wafer, while preventing the etchant from flowing over other areas of the second side of the wafer; and    thereby removing one or more of the layers from the outer margin of the second side while the layers remain at other areas of the second side of the wafer.    
   
   
       9 . The process of  claim 8  wherein the etchant also removes the boundary layer from the wafer at areas where the etchant contacts the wafer.  
   
   
       10 . A method for removing an oxide from a first side and from an outer margin of a second side of a workpiece through selective contact with an oxide etchant, comprising the steps of: 
 spinning the workpiece;    directing the oxide etchant to a first side of the workpiece;    with the oxide etchant moving radially outwardly via centrifugal force to contact substantially the entire first side of the workpiece, moving over and around the edge of the workpiece, and contacting an outer margin on the second side of the workpiece, while excluding the oxide etchant from a central area of a second side of the workpiece.    
   
   
       11 . The method of  claim 10  wherein the oxide etchant comprises a liquid including hydrofluoric acid.  
   
   
       12 . The method of  claim 1  further comprising the step of confining the process liquid to the perimeter area by controlling the temperature and flow rate of the process liquid.  
   
   
       13 . The method of  claim 1  further comprising the step of cutting off the introduction of fluid to the first surface of the workpiece, and continuing to spin the article.  
   
   
       14 . The method of  claim 1  further comprising the step of applying the process liquid by spraying the process liquid onto the workpiece.  
   
   
       15 . The method of  claim 1  further including the step of maintaining the fluid on a outer margin area of the second surface of the workpiece for a time interval sufficient to remove any layers or contaminants from the outer margin area and the edge of the workpiece.  
   
   
       16 . A method for removing metal from a workpiece, comprising the steps of: 
 securing the workpiece onto a rotor;    spinning the workpiece on the rotor;    performing a step to remove metal from a first side, the edge, and from only an outer margin of the second side of the workpiece, by contacting the first side, the edge, and the outer margin of the second side of the workpiece, with a metal removing liquid;    rising the workpiece; and    drying the workpiece.    
   
   
       17 . A process for removing metal contamination from a semiconductor wafer having a first side, and edge and a second side, and with a barrier layer on the wafer and a thin film or seed layer over at least a portion of the barrier layer, and a metal layer over at least a portion of the thin film layer, comprising: 
 spinning the wafer;    flowing a metal etchant onto the first side of the wafer, the edge of the wafer, and over an outer margin of the second side of the wafer, while preventing the etchant from flowing over other areas of the second side of the wafer;    thereby removing one or more of the layers from the outer margin of the second side while the layers remain at other areas of the second side of the wafer.