Method and apparatus for fluid processing a workpiece

Abstract

An apparatus for fluid processing at least one workpiece is provided. The apparatus includes a housing configured to hold a fluid, a workpiece holder disposed within the housing and configured to retain the at least one workpiece and an electric field shield plate disposed within the housing adjacent each of the at least one workpiece, the electric field shield plate having at least one contoured area configured to vary a distance between the electric field shield plate and a surface of the workpiece in a space between the at least one contoured area and a corresponding portion of the surface of the workpiece.

1 . An apparatus for fluid processing at least one workpiece, comprising:
 a housing configured to hold a fluid;   a workpiece holder disposed within the housing and configured to retain the at least one workpiece; and   an electric field shield plate disposed within the housing adjacent each of the at least one workpiece, the electric field shield plate having at least one contoured area configured to vary a gap from the electric field shield plate to a surface of the workpiece, the gap being defined by the at least one contoured area of the electric field shield plate and a corresponding portion of the surface of the workpiece facing the electric field shield plate.   
     
     
         2 . The apparatus of  claim 1 , wherein the electric field shield plate includes a non-conductive material configured to block a portion of an electric field passing through the plate to the surface of the workpiece. 
     
     
         3 . The apparatus of  claim 1 , wherein the electric field shield plate includes one or more contoured areas. 
     
     
         4 . The apparatus of  claim 3 , wherein the one or more contoured areas are configured to form one or more of a convex plate profile, a concave plate profile and a stepped plate profile. 
     
     
         5 . The apparatus of  claim 3 , wherein a transition between contoured areas is one of a smooth transition or an abrupt transition. 
     
     
         6 . The apparatus of  claim 3 , wherein the electric field shield plate includes a plurality of holes passing through the plate. 
     
     
         7 . The apparatus of  claim 6 , wherein a predetermined diameter of the holes of one of the one or more contoured areas is different than a predetermined diameter of the holes of another of the one or more contoured areas. 
     
     
         8 . The apparatus of  claim 6 , wherein a pattern of the holes of one of the one or more contoured areas is different than a pattern of the holes of another of the one or more contoured areas. 
     
     
         9 . The apparatus of  claim 6 , wherein a pattern of the holes forms a radial gradient radiating from a center of the plate. 
     
     
         10 . The apparatus of  claim 6 , wherein a pattern of the holes forms a linear gradient across the plate. 
     
     
         11 . The apparatus of  claim 1 , wherein the electric field shield plate is configured to control one or more of an electric field applied to the workpiece and a flow of fluid past the workpiece. 
     
     
         12 . An apparatus for fluid processing at least one workpiece, comprising:
 a housing configured to hold a fluid;   a workpiece holder disposed within the housing and configured to retain the at least one workpiece;   an electric field shield plate disposed within the housing adjacent each of the at least one workpiece configured to control one or more of an electric field applied to the workpiece and a fluid flow across a surface of the workpiece, the electric field shield plate including at least one contoured area that varies a gap from the electric field shield plate to the surface of the workpiece, the gap being defined by the at least one contoured area of the electric field shield plate and a corresponding portion of the surface of the workpiece facing the electric field shield plate; and   an agitation member disposed between the plate and the workpiece holder.   
     
     
         13 . The apparatus of  claim 12 , wherein the at least one contoured area is configured to form one or more of a convex plate profile, a concave plate profile and a stepped plate profile. 
     
     
         14 . The apparatus of  claim 12 , wherein the electric field shield plate includes a plurality of holes passing through the electric field shield plate and a predetermined diameter of the holes of one of the one or more contoured areas is different than a predetermined diameter of the holes of another of the one or more contoured areas. 
     
     
         15 . The apparatus of  claim 12 , wherein the electric field shield plate includes a plurality of holes and a pattern of the holes of one of the one or more contoured areas is different than a pattern of the holes of another of the one or more contoured areas. 
     
     
         16 . The apparatus of  claim 12 , wherein the electric field shield plate includes a plurality of holes passing through the electric field shield plate and a pattern of the holes forms a radial gradient radiating from a center of the electric field shield plate. 
     
     
         17 . The apparatus of  claim 12 , wherein the electric field shield plate includes a plurality of holes passing through the electric field shield plate and a pattern of the holes forms a linear gradient across the electric field shield plate. 
     
     
         18 . A method for controlling a flow of fluid over at least one workpiece, the method comprising:
 providing a housing configured to hold fluid;   providing a workpiece holder within the housing, the workpiece holder being configured to hold at least one workpiece;   providing an electric field shield plate within the housing adjacent each of the at least one workpiece, the electric field shield plate including at least one contoured area that varies a gap from the electric field shield plate to a surface of the workpiece, the gap being defined by the at least one contoured area of the electric field shield plate and a corresponding portion of the surface of the workpiece facing the electric field shield plate; and   passing a fluid between the electric field shield plate and the surface of the workpiece, wherein the at least one contoured area controls one or more of a fluid flow direction and a fluid flow rate over the surface of the workpiece in a space between the at least one contoured area and a corresponding portion of the surface of the workpiece.   
     
     
         19 . The method of  claim 18 , further comprising controlling an electric field across the surface of the workpiece with the electric field shield plate. 
     
     
         20 . The method of  claim 18 , further comprising providing a plurality of holes passing through the electric field shield plate. 
     
     
         21 . An apparatus for fluid processing at least one workpiece, the apparatus comprising:
 a housing configured to hold a fluid;   a workpiece holder disposed within the housing and configured to retain the at least one workpiece; and   a fluid agitation member disposed within the housing adjacent each of the at least one workpiece, the fluid agitation member adapted to move substantially parallel to a surface of the workpiece to agitate the fluid, the member having at least one contoured area configured to vary a gap from the member to the surface of the workpiece, the gap being defined by the at least one contoured area of the fluid agitation member and a corresponding portion of the surface of the workpiece facing the fluid agitation member.   
     
     
         22 . The apparatus of  claim 21 , wherein the member includes one or more contoured areas. 
     
     
         23 . The apparatus of  claim 21 , wherein the at least one contoured area is configured to form a stepped plate profile. 
     
     
         24 . The apparatus of  claim 21 , wherein the member defines a plurality of spaced openings. 
     
     
         25 . The apparatus of  claim 21 , wherein the member defines a plurality of blades separated by spaced openings, and wherein the at least one contoured area is provided within the plurality of blades. 
     
     
         26 . The apparatus of  claim 21  further comprising an electric field shield plate disposed within the housing adjacent each of the at least one workpiece, the electric field shield plate having at least one contoured area configured to vary a second gap between the electric field shield plate and a surface of the workpiece, the member disposed between the electric field shield plate and the workpiece.