Ingot puller apparatus having a heat shield disposed below a side heater and methods for preparing an ingot with such apparatus

An ingot puller apparatus for producing a silicon ingot comprising:

• a crucible for holding a melt of silicon, the crucible having a floor and a sidewall that extends from the floor;
• a growth chamber for pulling a silicon ingot from the melt along a pull axis;
• a lift mechanism for raising and lowering the crucible during crystal growth relative to the pull axis, the crucible moving axially between a lowest position in which a charge of silicon is melted to produce the silicon melt, a seed-dip position at which a seed crystal is initially contacted with the melt to pull the silicon ingot from the melt, and a terminal position in which the crucible has been depleted of melt;
• a side heater disposed radially outward to the crucible sidewall as the crucible travels from the lowest position to the terminal position;
• a bottom heater disposed below the crucible floor;
• and
• a heat shield disposed directly below the side heater.