Retainer for use in heat treatment of substrate, substrate heat treatment equipment, and method of manufacturing the retainer

Abstract

There is provided a retainer for use in heat treatment of a substrate which enables an increase in the accuracy of flatness of support sections for supporting a substrate. The retainer includes silicon wafer support sections for supporting a plurality of substrates by means of surface contact, and spacers for defining intervals of the silicon wafer support sections with respect to a vertical direction. Since the support sections and the spacers can be manufactured separately from each other, the accuracy of flatness of the support sections and intervals between the support sections with respect to the vertical direction are determined by the accuracy of individual support sections and spacers. So long as initial accuracy of support sections and that of spacers are maintained, a high-precision retainer can be obtained.

1 . A retainer for use in heat treatment of a substrate which supports a plurality of substrates in a horizontal position while said substrates are spaced away from each other with respect to a vertical direction, said retainer comprising: 
 a plurality of support sections for supporting said respective substrates by way of surface contact; and    spacers for defining intervals between said support sections with respect to the vertical direction.    
     
     
         2 . The retainer according to  claim 1 , further comprising a plurality of supports set upright on a pedestal for holding said support sections and the spacers, and wherein each of said support sections has a contact section for supporting said substrate bay way of surface contact as well as an engagement section engaging to said support; each of said spacers having an engagement section engaging to said support; and said support sections and said spacers being alternately fitted with said support.  
     
     
         3 . The retainer according to  claim 2 , wherein the engagement section of said support section is a hole formed so as to penetrate through said support section.  
     
     
         4 . The retainer according to  claim 2 , wherein said engagement section of said support section assumes the shapes of cut formed in said support section, and at least one portion of said cut are identical with the cross-sectional shape of said support.  
     
     
         5 . The retainer according to  claim 2 , wherein said engagement section of said spacer is a hole formed so as to penetrate through said spacer.  
     
     
         6 . The retainer according to  claim 2 , wherein said engagement section of said spacer assumes the shapes of cut formed in said spacer, and at least one portion of said cut are identical with the cross-sectional shape of said support.  
     
     
         7 . The retainer according to  claim 6 , wherein, in connection with the engagement portion between the spacer and the support, a protrusion is formed in either said spacer or said support, and a recess is formed in the remaining, and said protrusion and said recess are engaged with each other.  
     
     
         8 . The retainer according to  claim 2 , wherein said support sections and said spacers are fixed and sandwiched between a nut fastened to an upper end of each of said supports and said pedestal while remaining in close contact with each other with respect to a vertical direction.  
     
     
         9 . The retainer according to  claim 2 , wherein said support sections and said spacers are fixed together by means of thermocompression bonding.  
     
     
         10 . The retainer according to  claim 9 , wherein upper and lower surfaces of each of said support sections and upper and lower surfaces of each of said spacers are mirror finished.  
     
     
         11 . The retainer according to  claim 2 , wherein said support section is formed into the shape of a ring, and a cut is formed in a position on said support section where transport arm for transporting said substrate is to be loaded.  
     
     
         12 . The retainer according to  claim 11 , wherein an interior of said support section located opposite said cut is expanded outside from the remaining portion of said support section.  
     
     
         13 . The retainer according to  claim 11 , wherein a step is formed in a substrate-side of said support section along said contact section.  
     
     
         14 . The retainer according to  claim 11 , wherein said spacers are arranged such that the outer edges of a plurality of spacers arranged at the same level in height become close to the outer edge of said substrate.  
     
     
         15 . The retainer according to  claim 2 , wherein quartz glass is used as a principal material.  
     
     
         16 . A substrate heat treatment system comprising the retainer defined in any one of claims  1  through  15 .  
     
     
         17 . A method of manufacturing a retainer for use in heat treatment of a substrate, which retainer supports a plurality of substrates in a horizontal position while spacing said substrates away from each other with respect to a vertical direction, the method comprising the steps of: 
 fixedly placing a plurality of supports upright on a pedestal;    alternately fitting, to each of said supports, support sections for supporting the plurality of said substrates and spacers for defining intervals between said support sections in a vertical direction; and    fixing said support sections and said spacers while they remain in close contact with each other.    
     
     
         18 . The method of manufacturing a retainer according to  claim 17 , wherein said support sections and said spacers are fixed while remaining in a close contact with each other, by means of fastening a nut to an upper end of each of said supports.  
     
     
         19 . The method of manufacturing a retainer according to  claim 17 , further comprising a step of mirror finishing upper and lower surfaces of each of said support sections and upper and lower surfaces of each of said spacers; and wherein said support sections and said spacers are fixed to each other by thermocompression bonding.  
     
     
         20 . The method of manufacturing a retainer according to  claim 17 , further comprising: 
 a step of connecting a plurality of quartz glass plates by welding before said support section is fitted to said supports;    a step of abrading a surface of the connected quartz glass plate; and    a step of forming said support section by hollowing the connected quartz glass plate.