Methods for forming a single crystal silicon ingot with reduced crucible erosion are disclosed. Solid-phase quartz is added to the melt to reduce erosion at the crucible-melt surface interface. The quartz may be synthetic quartz such as synthetic quartz rods. The quartz may be disposed near the crucible-melt surface interface. Quartz dissolves and suppresses the amount of quartz that dissolves from the crucible at the crucible-melt surface interface.

Methods for forming a single crystal silicon ingot with reduced crucible erosion are disclosed. Solid-phase quartz is added to the melt to reduce erosion at the crucible-melt surface interface. The quartz may be synthetic quartz such as synthetic quartz rods. The quartz may be disposed near the crucible-melt surface interface. Quartz dissolves and suppresses the amount of quartz that dissolves from the crucible at the crucible-melt surface interface.

Methods for preparing an ingot in an ingot puller apparatus are disclosed. Thermal simulations are performed with the length of the ingot puller apparatus side heater being varied in the thermal simulations. A side heater is selected based on the thermal simulations. An ingot puller apparatus having the selected side heater length is provided. A seed crystal is lowered into a melt within a crucible of the ingot puller apparatus and an ingot is withdrawn from the melt.

Methods for preparing an ingot in an ingot puller apparatus are disclosed. Thermal simulations are performed with the length of the ingot puller apparatus side heater being varied in the thermal simulations. A side heater is selected based on the thermal simulations. An ingot puller apparatus having the selected side heater length is provided. A seed crystal is lowered into a melt within a crucible of the ingot puller apparatus and an ingot is withdrawn from the melt.

A crystal piece of monocrystalline silicon suitable for the production of semiconductor wafers has a length of not less than 8 cm and not more than 50 cm and a diameter of not less than 280 mm and not greater than 320 mm, wherein the fraction of the semiconductor wafers produced therefrom that are free from pinholes having a size of not more than 30 μm is greater than 98%.

Methods for forming a unitized crucible assembly for holding a melt of silicon for forming a silicon ingot are disclosed. In some embodiments, the methods involve a porous crucible mold having a channel network with a bottom channel, an outer sidewall channel that extends from the bottom channel, and a central weir channel that extends from the bottom channel. A slip slurry may be added to the channel network and the liquid carrier of the slip slurry may be drawn into the mold. The resulting green body may be sintered to form the crucible assembly.

Methods for forming a unitized crucible assembly for holding a melt of silicon for forming a silicon ingot are disclosed. In some embodiments, the methods involve a porous crucible mold having a channel network with a bottom channel, an outer sidewall channel that extends from the bottom channel, and a central weir channel that extends from the bottom channel. A slip slurry may be added to the channel network and the liquid carrier of the slip slurry may be drawn into the mold. The resulting green body may be sintered to form the crucible assembly.

A cold crucible usable in the field of high-temperature production of monocrystalline materials. The cold crucible includes: a cold cage which has sectors made of a material having good electrical conductivity and in which a charge is melted, and a cooling device with heat transfer fluid, configured to cool each segment of the cold cage from the inside. The cold crucible is essentially such that it further includes at least one device for generating a static magnetic field, each generating device being housed inside one of the sectors of the cold crucible. Each static magnetic field thus generated having the effect of slowing down the electromagnetic stirring of the molten charge, such that it is possible to produce monocrystalline ingots of significantly larger diameter than the diameter of the seed initiating their growth.

An apparatus for manufacturing a single crystal according to a Czochralski method, including: a main chamber housing crucibles for a raw-material melt and heater for heating the raw-material melt; a pulling chamber at an upper portion of the main chamber and a single crystal pulled from the raw-material melt; a cooling cylinder extending from a ceiling portion of the main chamber toward a surface of the raw-material melt to surround the single crystal; an auxiliary cooling cylinder inside the cooling cylinder; and a diameter-enlargement member to fit into the auxiliary cooling cylinder. The auxiliary cooling cylinder has a slit penetrating in an axial direction to come into close contact with the cooling cylinder by pushing the diameter-enlargement member into the auxiliary cooling cylinder to enlarge the diameter of the auxiliary cooling cylinder. This enables efficient cooling of a growing single crystal and increases the growth rate of the single crystal.

An apparatus for manufacturing a single crystal according to a Czochralski method, including: a main chamber housing crucibles for a raw-material melt and heater for heating the raw-material melt; a pulling chamber at an upper portion of the main chamber and a single crystal pulled from the raw-material melt; a cooling cylinder extending from a ceiling portion of the main chamber toward a surface of the raw-material melt to surround the single crystal; an auxiliary cooling cylinder inside the cooling cylinder; and a diameter-enlargement member to fit into the auxiliary cooling cylinder. The auxiliary cooling cylinder has a slit penetrating in an axial direction to come into close contact with the cooling cylinder by pushing the diameter-enlargement member into the auxiliary cooling cylinder to enlarge the diameter of the auxiliary cooling cylinder. This enables efficient cooling of a growing single crystal and increases the growth rate of the single crystal.