Ingot puller apparatus having heat shields with voids therein

An ingot puller apparatus for growing a single crystal silicon ingot from a melt of silicon, the apparatus comprising:

• a puller housing defining a growth chamber;
• a crucible disposed within the growth chamber for containing the melt of silicon;
• a pulling mechanism for pulling the ingot from the melt along a pull axis;
• and
• a heat shield disposed within the growth chamber, the heat shield defining a central passage for receiving the ingot as the ingot is pulled by the pulling mechanism, the heat shield comprising:
• a leg segment that extends downward relative to the pull axis, the leg segment comprising a leg segment housing that defines a leg chamber;
• insulation disposed within the leg chamber;
• a ledge disposed in the leg chamber, the insulation being supported by the ledge, the insulation being separated from the leg segment housing by a gap, the gap being disposed above the ledge;
• and
• a foot that extends from the leg segment at a distal end of the leg segment, wherein a distance between at least a portion of the foot and the pull axis is less than a distance between the leg segment and the pull axis;
• and
• wherein the leg segment has a void formed therein, at least a portion of the void being disposed below the ledge.