Method and system for cleaning a semiconductor wafer

Abstract

A method and a system are provided for cleaning a surface of a wafer. The method starts by scrubbing the surface of the wafer with a cleaning brush that applies a chemical solution to the surface of the wafer. In one example, the cleaning brush implements a through the brush (TTB) technique to apply the chemicals. The scrubbing is generally performed in a brush box, with a top cleaning brush and a bottom cleaning brush. The top cleaning brush is then removed from contact with the surface of the wafer. The chemical concentration in the top brush may be maintained at substantially the same concentration that was in the brush during the scrubbing operation. Next, a flow of water (preferably de-ionized water) is delivered to the surface of the wafer. The delivery of water is preferably configured to remove substantially all of the chemical solution from the surface of the wafer before proceeding to a next cleaning operation.

What is claimed is:  
     
         1 . A method of cleaning a surface of a wafer, comprising: 
 scrubbing the surface of the wafer with a cleaning brush that applies a chemical solution to the surface of the wafer;    removing the cleaning brush from contact with the surface of the wafer; and    delivering a flow of water to the surface of the wafer, the delivering being configured to substantially remove the chemical solution from the surface of the wafer.    
     
     
         2 . A method of cleaning a surface of a wafer as recited in  claim 1 , wherein the cleaning brush that applies the chemical solution implements a through the brush (TTB) chemical delivery technique.  
     
     
         3 . A method of cleaning a surface of a wafer as recited in  claim 1 , wherein the scrubbing is performed in a brush box, the brush box having the cleaning brush and a second cleaning brush.  
     
     
         4 . A method of cleaning a surface of a wafer as recited in  claim 3 , wherein the second cleaning brush is implemented to scrub a bottom surface of the wafer.  
     
     
         5 . A method of cleaning a surface of a wafer as recited in  claim 1 , wherein the removing of the cleaning brush from contact with the surface of the wafer completes a chemical cleaning operation.  
     
     
         6 . A method of cleaning a surface of a wafer as recited in  claim 1 , wherein the delivering of the flow of water to the surface of the wafer further comprises: 
 setting a first delivery source and a second delivery source over the surface of the wafer in order to deliver the flow of water to the surface of the wafer; and    wherein between about 150 ml/minute and about 750 ml/minute of water flows through each of the first and second delivery sources.    
     
     
         7 . A method of cleaning a surface of a wafer as recited in  claim 6 , further comprising: 
 setting a pressure ranging between about 20 psi and about 50 psi for the first delivery source and the second delivery source.    
     
     
         8 . A method of cleaning a surface of a wafer as recited in  claim 6 , further comprising: 
 setting a time ranging between about 5 seconds and about 60 seconds for the delivering of the flow of water to the surface of the wafer.    
     
     
         9 . A method of cleaning a surface of a wafer as recited in  claim 6 , further comprising: 
 continuing the delivering of the flow of water to the surface of the wafer until a pH of fluids over the surface of the wafer is at least about 4 or greater.    
     
     
         10 . A method of cleaning a surface of a wafer as recited in  claim 6 , further comprising: 
 continuing the delivering of the flow of water to the surface of the wafer until a pH of fluids over the surface of the wafer is at most about 8.5 or less.    
     
     
         11 . A method of cleaning a surface of a wafer as recited in  claim 1 , wherein the chemical solution on the cleaning brush is maintained at a substantially constant chemical concentration during the scrubbing and during the delivering.  
     
     
         12 . A method for cleaning a semiconductor wafer, comprising: 
 introducing the wafer into a brush box;    supporting the wafer with a bottom brush and a set of rollers;    scrubbing a top surface of the wafer with a top cleaning brush that applies a chemical solution to the surface of the wafer;    removing the top cleaning brush from the top surface of the wafer; and    rinsing the top surface of the semiconductor wafer with a cleaning fluid while the top cleaning brush is removed from the top surface.    
     
     
         13 . The method of  claim 12 , wherein the cleaning fluid is deionized water.  
     
     
         14 . The method of  claim 12 , wherein the method operation of supporting the wafer with a bottom brush and a set of rollers includes, 
 rotating the wafer at a speed of about 20 rotations per minute.    
     
     
         15 . The method of  claim 12 , further comprising: 
 removing the wafer from the brush box; and    repeating the scrubbing with another wafer without rinsing the top cleaning brush.