Apparatus for wet processing of a planar workpiece, device for a cell of the apparatus and method of operating the apparatus

Abstract

A device for a cell of an apparatus for wet processing of a planar workpiece, comprises a structure comprising first and second walls. The workpiece is movable in a central plane through a space between the first and second walls in a first direction (y). Apertures for introducing pressurised liquid between the first and second walls are on opposite sides of the central plane and facing the central plane. The apertures are distributed in the first direction (y) and in a second direction (x) transverse to the first direction (y). Discharge openings for the liquid to leave the space are on opposite sides, in the second direction (x), along the space in the first direction (y). The first and second walls form barriers to liquid flow from the space in a direction (z) perpendicular to the central plane. Channels through the walls are arranged to conduct liquid to respective one of the apertures.

1 . (canceled) 
     
     
         2 . Method of operating an apparatus for wet electrolytic treatment processing of a planar workpiece, the method comprising:
 providing a device comprising a structure with first and second walls defining a space therebetween, wherein apertures for introducing pressurized liquid are provided on opposite sides of a central plane and facing the central plane, and wherein discharge openings for the liquid to leave the space are defined on opposite sides of the space;   moving the planar workpiece through the space in the central plane in a first direction;   pumping liquid through channels provided through the first and second walls to respective apertures at a rate sufficient to create liquid flows that maintain the workpiece substantially in the central plane; and   directing the liquid flows from the apertures toward the discharge openings in a second direction transverse to the first direction.   
     
     
         3 . Method according to  claim 2 , wherein the liquid is pumped at a velocity of at least 0.1 m/s at the discharge openings. 
     
     
         4 . Method according to  claim 2 , wherein the liquid is pumped at a velocity of at most 10 m/s at the discharge openings. 
     
     
         5 . Method according to  claim 2 , wherein the workpiece has a thickness of at most 100 μm. 
     
     
         6 . Method according to  claim 2 , further comprising applying an electrical potential between the workpiece and at least one electrode positioned between the central plane and one of the first and second walls to perform electroplating of the workpiece. 
     
     
         7 . Method according to  claim 2 , wherein moving the workpiece comprises engaging the workpiece with at least one clamp at an edge of the workpiece and driving movement of the clamp along the first direction. 
     
     
         8 . Method according to  claim 2 , wherein the liquid flows create a self-centering effect that returns any section of the workpiece that deviates from the central plane back toward the central plane. 
     
     
         9 . Method according to  claim 2 , wherein the apertures are provided at a surface density of at least 460 apertures per m 2  on each of the first and second walls. 
     
     
         10 . Method according to  claim 2 , further comprising recirculating the liquid that exits through the discharge openings back to the channels. 
     
     
         11 . Method according to  claim 2 , wherein the workpiece is a discrete workpiece selected from the group consisting of a semiconductor substrate, a photovoltaic device substrate, and a flexible electronic device substrate.