Apparatus and method for growing a crystal and heating an annular channel circumscribing the crystal

An apparatus for pulling a crystal seed from melt for growing a single crystal, the apparatus comprising:

• a sealed chamber;
• a crucible disposed within the sealed chamber including an outer container and an inner container disposed substantially coaxially in the outer container, wherein a protruding portion of the inner container protrudes downward relative to the outer container for containing melt, the inner and outer containers defining an annular channel therebetween which has a bottom wall and contains introduced charge feed, wherein means are provided for allowing fluid communication between the annular channel and the inner container;
• at least one charge feed tube having a first and second end portion, wherein additional charge feed is introduced through the charge feed tube via an opening in the first end portion and delivered to the annular channel via an opening in the second end portion;
• and
• a heater device disposed within the annular channel above the bottom wall thereof, for generating heat proximal a top surface of the charge feed, in order to prevent the formation of a condensate of the charge feed within the annular channel.