Abstract: A silicon single crystal pull-up apparatus includes a crucible for containing a molten silicon material, an annular heater disposed so as to surround the crucible for heating the silicon material in the crucible, and a plurality of plate-like members made of heat insulation material and disposed so as to surround the heater, each of the plate-like members has an arc-shaped cross section not less than a two-third circle and is connected with each other at respective side edges thereof such that the plurality of the plate-like members are assembled into a shape of a cylinder having wave-like circumferential side walls.

Abstract: A component for a semi-conductor diffusion furnace includes a sintered silicon carbide matrix resulting from sintering of silicon carbide powder. The silicon carbide power consists essentially of silicon carbide having an average particle size of 10-200 microns (preferably 30-170 microns) and is mixed with fine carbon powder and fine silicon powder.