Methods and apparatus for processing the backsides of wafers

Abstract

In one aspect, a method of processing the backsides of a batch of semiconductor wafers includes receiving a cassette for wafers in its inverted orientation in which the wafers are horizontally orientated with their front faces facing downwardly, removing the wafers sequentially, or as a batch, and processing the upwardly facing backsides of the wafers. In another aspect, an apparatus for processing wafers from a cassette holding wafers horizontally includes a cassette support where the cassette support is formed to receive an industry standard cassette in its inverted position but not in its upright position.

1 . A method of processing the backsides of a batch of semiconductor wafers including: 
 (a) receiving a cassette for wafers in its inverted orientation in which the wafers are horizontally orientated with their front faces facing downwardly.    (b) removing the wafers sequentially, or as a batch; and    (c) processing the upwardly facing backsides of the wafers.    
   
   
       2 . A method as claimed in  claim 1  wherein the wafers are returned to an inverted cassette.  
   
   
       3 . A method as claimed in  claim 1  wherein an unloaded cassette is re-inverted.  
   
   
       4 . A method as claimed in  claim 1  including inverting the cassette from its normal orientation in which the wafers have their front faces facing upwardly.  
   
   
       5 . Apparatus for processing wafers from a cassette holding wafers horizontally including a cassette support wherein the cassette support is formed to received an industry standard cassette in its inverted position but not in its upright position.  
   
   
       6 . Apparatus as claimed in  claim 5  wherein the support includes means for varying its upper surface profile between a profile which will accept an upright cassette and a surface that will receive an inverted cassette.  
   
   
       7 . Apparatus as claimed in  claim 5  further including means for rotating a cassette through 180°.  
   
   
       8 . Apparatus as claimed in  claim 7  wherein the profile varying means operates in synchronism with the cassette rotating means.  
   
   
       9 . Apparatus for processing a wafer from a cassette including a cassette support, means for determining the orientation of a cassette and cassette handling means for placing the cassette on the cassette support in a desired orientation.  
   
   
       10 . Apparatus as claimed in  claim 9  including a cassette support formed to receive an industry standard cassette in its inverted position, but not in its upright position.