Method of reducing surface contamination in semiconductor wet-processing vessels

Abstract

A method and apparatus for reducing the contaminants in a wet etching bath by rapidly removing a substantial portion of the etching liquid from the bath such that the contaminants are removed from the air/liquid interface of the bath surface is describe. By rapidly removing a substatial portion of the etching liquid from the bath, contaminants that are trapped by eddy currents and liquid/air surface tension forces are greatly reduced at the surface of the bath. The semiconductor wafers treated showed reduced levels of contamination.

1 - 27 . (canceled)  
   
   
       28 . An etching bath apparatus for reducing the contamination of semiconductor wafers during wet processing, said apparatus comprising: 
 an etching vessel having a sufficient volume to hold a predetermined amount of etching fluid;    said etching vessel having a plurality of side walls, at least one of said plurality of side walls having at least one gate located near the top of said side walls to rapidly remove a portion of etching fluid from said etching vessel.    
   
   
       29 . The etching bath apparatus according to  claim 28 , wherein etching fluid is continuously fed into said etching vessel during processing and the excess etching fluid is removed by cascading over the top of the plurality of side walls of said etching vessel.  
   
   
       30 . The etching bath apparatus according to  claim 29 , wherein said etching vessel has a single gate to remove to rapidly remove an upper portion of etching fluid from said etching vessel.  
   
   
       31 . The etching bath apparatus according to  claim 30 , wherein said upper portion of said etching solution is rapidly removed during the cascade operation.  
   
   
       32 . The etching apparatus according to  claim 30 , wherein said gate is hingedly attached to one of said side walls.  
   
   
       33 . The etching apparatus according to  claim 30 , wherein said at least one gate is slideably mounted to one of said plurality of walls.  
   
   
       34 . The etching apparatus according to  claim 33 , wherein said apparatus has a single gate.  
   
   
       35 . An etching vessel comprising: 
 a first hollow container;    a second hollow container;    said first hollow container being located beneath said second hollow container and sealingly engaged to said second hollow container such that said first and said second hollow containers form said etching vessel;    said first hollow container and said second hollow container having a size such that said second hollow container can slide over said first hollow container;    said etching vessel having a sufficient volume to hold a predetermined amount of etching fluid; and    wherein said second hollow container is moveable relative to said first hollow container to rapidly remove said etching fluid from an upper portion of said etching vessel.    
   
   
       36 . The etching vessel according to  claim 35 , wherein etching fluid is continuously fed into said etching vessel and the excess etching fluid is removed by cascading over the top said second hollow container.  
   
   
       37 . An etching bath apparatus comprising: 
 an etching vessel, said etching vessel including means for rapidly removing a portion of the etching fluid from the upper portion of said etching vessel.    
   
   
       38 . The etching bath apparatus according to  claim 37 , wherein said means for rapidly removing a portion of the etching fluid from the upper portion of said etching vessel includes a gate.  
   
   
       39 . The etching bath apparatus according to  claim 37 , wherein said means for rapidly removing a portion of the etching fluid from the upper portion of said etching vessel includes a slideable dopr.  
   
   
       40 . The etching bath apparatus according to  claim 37 , wherein said means for rapidly removing a portion of the etching fluid from the upper portion of said etching vessel includes a door.  
   
   
       41 . The etching bath apparatus according to  claim 35 , wherein said means for rapidly removing a portion of the etching fluid from the upper portion of said etching vessel includes a valve.  
   
   
       42 . The etching bath apparatus according to  claim 37 , wherein said means for rapidly removing a portion of the etching fluid from the upper portion of said etching vessel includes a paddle.  
   
   
       43 . The etching bath apparatus according to  claim 37 , wherein said means for rapidly removing a portion of the etching fluid from the upper portion of said etching vessel includes a collapsible member.  
   
   
       44 . (canceled)  
   
   
       45 . An apparatus for wet processing semiconductor wafers to reduce the contamination on the silicon wafer during a wet process, said apparatus comprising: 
 an etching vessel;    a semiconductor wafer boat;    a system for rapidly removing said semiconductor wafer boat from said etching vessel to remove surface contaminants from the etching fluid before said semiconductor wafers are removed from said etching fluid; and    an outer weir.    
   
   
       46 . The apparatus according to  claim 45 , wherein said etching vessel has baffles located at the bottom of said etching vessel to selectively allow etching fluid to flow past said wafer boat.  
   
   
       47 . The apparatus according to  claim 45 , wherein said system includes a moveable arm which is fixably mounted to said wafer boat.