High strength camfer on quartzware

Abstract

A structural member for use in extremely high temperature environments that has substantially flat exterior for resting on a flat surface. The substantially flat exterior of the structural member has a low angle chamfer that is preferably less than 45 degrees and that rises far enough above the flat surface so that when the edge is rolled using conventional processing methods, the resulting high point does not extend a distance far enough to contact with the surface.

1 . A structural member for use in extremely high temperature environments having:
 a frame having an upper surface and a lower surface;   said lower surface having a substantially planar exterior engaging surface and an outer edge;   a chamfer extending from said substantially planar exterior engaging surface toward said outer edge by a defined distance away from said exterior engaging surface at said outer edge such that when the lower surface is fire polished resulting burms along said outer edge are shorter than said defined distance.   
     
     
         2 . The structural member of  claim 1 , wherein said structural member is a boat for heating silicon wafers therein. 
     
     
         3 . The structural member of  claim 1 , wherein said structural member is formed of materials selected from SiO 2  group. 
     
     
         4 . The structural member of  claim 3 , wherein said structural member is formed of fused silica. 
     
     
         5 . The structural member of  claim 1 , wherein said chamfer extends inwards from said outer edge by a second defined distance. 
     
     
         6 . The structural member of  claim 5 , wherein said second defined distance is between 2 to 5 millimeters. 
     
     
         7 . The structural member of  claim 1 , wherein said defined distance is between 0.25 to 2 millimeters. 
     
     
         8 . The structural member of  claim 1 , further including a radius transitioning from said lower to said chamfer. 
     
     
         9 . The structural member of  claim 8 , wherein said radius is large. 
     
     
         10 . The structural member of  claim 1 , wherein said chamfer angle is less than 45 degrees.