Truncated dummy plate for process furnace

Abstract

A truncated dummy plate which is suitable for promoting substantially uniform flow of process gases among all regions on the surface of a substrate to facilitate deposition of a film having uniform thickness on the substrate. The truncated dummy plate has a circular shape with a flat edge provided in the curved edge of the dummy plate. At least two, and preferably, about three or four of the dummy plates are positioned in the sites on a wafer boat which are in relatively close proximity to a gas outlet in a process furnace typically during a LPCVD process carried out in the furnace. The flat or truncated edges of the dummy plates are disposed on the gas inlet side of the process chamber, with the round edges of the dummy plates disposed on the gas outlet side of the process chamber.

1 - 12 . (canceled)  
   
   
       13 . A method of promoting a substantially uniform flow of a reaction gas in a reaction chamber having a gas inlet provided on a gas inlet side of said reaction chamber and a gas outlet provided on a gas outlet side of said reaction chamber, said method comprising: 
 providing a wafer boat;    providing at least two dummy plates each comprising a truncated plate body having a curved edge and a flat edge shaped in said curved edge of said plate body; and    positioning said at least two dummy plates in said wafer boat adjacent to said gas outlet, with said flat edge of said at least two dummy plates disposed on said gas inlet side of said reaction chamber.    
   
   
       14 . The method of  claim 13  wherein a maximum distance between said curved edge and said flat edge is about 15 cm.  
   
   
       15 . The method of  claim 13  wherein said truncated plate body has a maximum width of about 20 cm.  
   
   
       16 . The method of  claim 15  wherein a maximum distance between said curved edge and said flat edge is about 15 cm.  
   
   
       17 . The method of  claim 13  wherein said at least two dummy plates comprises three dummy plates.  
   
   
       18 . The method of  claim 17  wherein a maximum distance between said curved edge and said flat edge is about 15 cm.  
   
   
       19 . The method of  claim 17  wherein said truncated plate body has a maximum width of about 20 cm.  
   
   
       20 . The method of  claim 19  wherein a maximum distance between said curved edge and said flat edge is about 15 cm.  
   
   
       21 . A method of promoting a substantially uniform flow of a reaction gas in a reaction chamber having a gas inlet provided on a gas inlet side of said reaction chamber and a gas outlet provided on a gas outlet side of said reaction chamber, said method comprising: 
 providing a wafer boat having a plurality of lower sites, a plurality of center sites and a plurality of upper sites;    providing at least two dummy plates each comprising a truncated plate body having a curved edge and a flat edge shaped in said curved edge of said plate body; and    positioning said at least two dummy plates in respective slots of at least one of said plurality of lower sites, said plurality of center sites and or said plurality of upper sites of said wafer boat, with said flat edge of said at least two dummy plates disposed on said gas inlet side of said reaction chamber.    
   
   
       22 . The method of  claim 21  wherein said positioning said at least two dummy plates in respective slots of at least one of said plurality of lower sites, said plurality of center sites and said plurality of upper sites of said wafer boat comprises positioning said at least two dummy plates in respective slots of said plurality of lower sites.  
   
   
       23 . The method of  claim 21  wherein said positioning said at least two dummy plates in respective slots of at least one of said plurality of lower sites, said plurality of center sites and said plurality of upper sites of said wafer boat comprises positioning said at least two dummy plates in respective slots of said plurality of center sites.  
   
   
       24 . The method of  claim 21  wherein a maximum distance between said curved edge and said flat edge is about 15 cm.  
   
   
       25 . The method of  claim 21  wherein said truncated plate body has a maximum width of about 20 cm.  
   
   
       26 . The method of  claim 21  wherein said at least two dummy plates comprises three dummy plates.  
   
   
       27 . A method of promoting a substantially uniform flow of a reaction gas in a reaction chamber having a gas inlet provided on a gas inlet side of said reaction chamber and a gas outlet provided on a gas outlet side of said reaction chamber, said method comprising: 
 providing a wafer boat having a plurality of lower sites, a plurality of center sites and a plurality of upper sites;    providing at least two dummy plates each comprising a truncated plate body having a curved edge and a flat edge shaped in said curved edge of said plate body; and    positioning said at least two dummy plates in respective slots of said plurality of upper sites of said wafer boat, with said flat edge of said at least two dummy plates disposed on said gas inlet side of said reaction chamber.    
   
   
       28 . The method of  claim 27  wherein a maximum distance between said curved edge and said flat edge is about 15 cm.  
   
   
       29 . The method of  claim 27  wherein said truncated plate body has a maximum width of about 20 cm.  
   
   
       30 . The method of  claim 27  wherein said at least two dummy plates comprises three dummy plates.