Wafer cleaning brush

Abstract

A semiconductor wafer scrubber has a brush with a nubless outer surface for cleaning the surfaces of a semiconductor wafer. The nubless brush has a body and rotates around a central axis as it contacts the wafer surface. The brush has a central section with an outer diameter less than the diameter of the end sections.

1 . An apparatus comprising: 
 a wafer scrubber to position and hold a semiconductor wafer; and    a rotatable brush mounted in the wafer scrubber to contact the semiconductor wafer, the rotatable brush having a nubless outer surface, at least a portion of the nubless outer surface being generally cylindrical.    
     
     
         2 . The apparatus of  claim 1  wherein the rotatable brush has first and second cylindrical end sections.  
     
     
         3 . The apparatus of  claim 1  wherein the rotatable brush has first and second cylindrical end sections and a central section, the first and second cylindrical end sections having outer diameters greater than the outer diameter of the central section.  
     
     
         4 . The apparatus of  claim 2  wherein the rotatable brush has a midpoint having an outer diameter less than the diameter of the first and second cylindrical end sections.  
     
     
         5 . The apparatus of  claim 3  wherein the central section of the rotatable brush is tapered.  
     
     
         6 . The apparatus of  claim 3  further comprising a shoulder between each of the first and second cylindrical end sections and the central section.  
     
     
         7 . The apparatus of  claim 1  wherein the rotatable brush has a poly vinyl acetate nubless outer surface.  
     
     
         8 . An apparatus comprising: 
 a semiconductor wafer oriented in a cleaning position; and    first and second rotating brushes at the cleaning position to contact the semiconductor wafer, at least one of the rotating brushes having a nubless outer surface.    
     
     
         9 . The apparatus of  claim 8  wherein the rotating brush having a nubless outer surface has a first cylindrical end section, a second cylindrical end section, and a central section between the first and second cylindrical end sections, the first and second cylindrical end sections having outer diameters greater than the outer diameter of the central section.  
     
     
         10 . The apparatus of  claim 9  wherein the central section is tapered.  
     
     
         11 . The apparatus of  claim 9  further comprising a shoulder between each of the cylindrical end sections and the central section.  
     
     
         12 . The apparatus of  claim 8  further comprising at least one roller to engage the semiconductor wafer and rotate the wafer as the first and second rotating brushes contact the wafer.  
     
     
         13 . The apparatus of  claim 8  wherein the first and second rotating brushes have a softness of between 50 g/cm 2  and 110 g/cm 2 .  
     
     
         14 . The apparatus of  claim 8  wherein the first and second rotating brushes have poly vinyl acetate outer surfaces.  
     
     
         15 . A method comprising: 
 holding a semiconductor wafer on a conveyor, the wafer having a first surface and a second surface;    rotating the semiconductor wafer about a first axis perpendicular to the first and second surfaces;    contacting the first surface of the semiconductor wafer with a first rotating brush having a nubless outer surface; and    contacting the second surface of the semiconductor wafer with a second rotating brush having a nubless outer surface.    
     
     
         16 . The method of  claim 15  further comprising contacting at least one of the first and second surfaces of the semiconductor wafer with a rotating brush having a nubless outer surface and a non-uniform outer diameter.  
     
     
         17 . The method of  claim 15  further comprising contacting at least one of the first and second surfaces of the semiconductor wafer with a rotating brush having a nubless outer surface and a tapered central section.  
     
     
         18 . The method of  claim 15  further comprising contacting at least one of the first and second surfaces of the semiconductor wafer with a rotating brush having a nubless outer surface with a softness of 30 g/cm 2  to 150 g/cm 2 .  
     
     
         19 . The method of  claim 15  further comprising engaging at least one roller against the edge of the semiconductor wafer to rotate the semiconductor wafer.  
     
     
         20 . The method of  claim 15  further comprising contacting at least one of the first and second surfaces of the semiconductor wafer with a rotating brush having a nubless poly vinyl acetate outer surface.