Wafer side edge cleaning apparatus

Abstract

A wafer side edge cleaning apparatus includes: a cleaning device including a fixing element and a wafer brush disposed beneath the fixing element. The wafer brush is in the shape of a frustum. The frustum has a tapered surface contacting with a side edge of a wafer. The top surface of the frustum is larger than the bottom surface of the frustum. When cleaning the side edge of the wafer, the wafer and the wafer brush are rotated in different directions and a cleaning solution flows out from the fixing element rinses and washes the side edge brush.

1 . A wafer side edge cleaning apparatus comprising:
 a wafer stage for holding and rotating a wafer, wherein the wafer has a side edge; and   a cleaning element comprising:
 a fixing element; and 
 a wafer brush fixed onto the fixing element, wherein the wafer brush has a tapered surface contacting the side edge of the wafer, the tapered surface defines a bottom surface and a top surface of the wafer brush, the bottom surface is away from the fixing element, the top surface contacts the fixing element, and the bottom surface is smaller than the top surface, and wherein a cleaning solution rinses the wafer brush when the side edge of the wafer is subject to cleaning by the wafer brush. 
   
     
     
         2 . The wafer side edge cleaning apparatus of  claim 1 , wherein the tapered surface and the top surface define an included angle between 30 and 90 degrees. 
     
     
         3 . The wafer side edge cleaning apparatus of  claim 2 , wherein the included angle is between 45 and 80 degrees. 
     
     
         4 . The wafer side edge cleaning apparatus of  claim 1 , wherein the fixing element comprises at least one opening and the cleaning solution flows out from the opening. 
     
     
         5 . The wafer side edge cleaning apparatus of  claim 1 , wherein the cleaning solution comprises de-ionized water. 
     
     
         6 . The wafer side edge cleaning apparatus of  claim 5 , wherein the cleaning solution comprises conductive ions. 
     
     
         7 . The wafer side edge cleaning apparatus of  claim 1 , wherein the wafer brush comprises resin. 
     
     
         8 . The wafer side edge cleaning apparatus of  claim 7 , wherein the wafer brush comprises poly vinyl alcohol (PVA). 
     
     
         9 . The wafer side edge cleaning apparatus of  claim 1 , wherein when the side edge of the wafer is subject to cleaning, the wafer is rotated to a first direction, and the wafer brush is rotated to a second direction so that contaminants on the side edge can be adsorbed on the wafer brush. 
     
     
         10 . The wafer side edge cleaning apparatus of  claim 1 , further comprising a bolt disposed under the fixing element and penetrating the wafer brush, and a nut disposed under the wafer brush and screwed on the bolt to fix the wafer brush on the fixing element. 
     
     
         11 . The wafer side edge cleaning apparatus of  claim 1 , wherein the side edge of the wafer comprises a bevel.