Heat-treatment furnace

Abstract

The disclosed heat-treatment furnace, used in a semiconductor-substrate heat-treatment step, is characterized by the provision of a cylindrical core, both ends of which have openings sized so as to allow insertion and removal of semiconductor substrates. This reduces standby time between batches during consecutive semiconductor heat treatment, thereby improving productivity. Furthermore, the use of a simple cylindrical shape for the structure of the core reduces the frequency at which gas-introduction pipe sections fail, thereby decreasing the running cost of the heat-treatment process.

1 . A heat-treatment furnace for use in the heat treatment of semiconductor substrates, comprising a cylindrical core tube which is provided at opposite ends with openings having a sufficient size to allow semiconductor substrates to be moved into and out of the core tube. 
     
     
         2 . The heat-treatment furnace of  claim 1 , further comprising lids each of which is detachably mounted to the core tube to block the opening to substantially seal the core tube. 
     
     
         3 . The heat-treatment furnace of  claim 1 , further comprising thin gas inlet conduits penetrating through the lids for introducing gas into the core tube. 
     
     
         4 . The heat-treatment furnace of  claim 1 , further comprising thin gas inlet conduits disposed near opposite ends of the core tube for introducing gas into the core tube. 
     
     
         5 . The heat-treatment furnace of  claim 1 , further comprising a thin gas inlet conduit disposed near the longitudinal center of the core tube for introducing gas into the core tube. 
     
     
         6 . The heat-treatment furnace of  claim 1 , wherein the opening in the core tube has an inner diameter which is at least 95% of the inner diameter of the core tube at the center. 
     
     
         7 . The heat-treatment furnace of  claim 1 , further comprising at least one boat station disposed outside the core tube and in proximity to the opening in the core tube, the boat station carrying a boat having semiconductor substrates rested thereon on standby. 
     
     
         8 . The heat-treatment furnace of any  claim 1 , wherein the heat treatment is intended to diffuse a p- or n-type dopant into silicon substrates. 
     
     
         9 . The heat-treatment furnace of  claim 1 , wherein the heat treatment is intended to oxidize silicon substrates.