A casting method and cast article are provided. The casting method includes providing a casting furnace, the casting furnace including a withdrawal region in a lower end, positioning a mold within the casting furnace, positioning a molten material in the mold, partially withdrawing the mold a withdrawal distance through the withdrawal region in the casting furnace, the withdrawal distance providing a partially withdrawn portion, then reinserting at least a portion of the partially withdrawn portion into the casting furnace through the withdrawal region, and then completely withdrawing the mold from the casting furnace. The reinserting at least partially re-melts a solidified portion within the partially withdrawn portion to reduce or eliminate freckle grains. The cast article includes a microstructure and occurrence of freckle grains corresponding to being formed by a process comprising partially withdrawing, reinserting, and completely withdrawing of a mold from a casting furnace to form the cast article.

A method for forming a wafer supporting structure comprises growing a single crystal using a floating zone crystal growth process, forming a silicon ingot having an oxygen concentration equal to or less than 1 parts-per-million-atomic (ppma), slicing a wafer from the silicon ingot, cutting portions of the wafer to form a supporting structure through a mechanical lathe and applying a high temperature anneal process to the supporting structure.

To provide polycrystalline silicon suitable as a raw material for production of single-crystalline silicon. A D/L value is set within the range of less than 0.40 when multiple pairs of silicon cores are placed in a reaction furnace in production of a polycrystalline silicon rod having a diameter of 150 mm or more by deposition according to a chemical vapor deposition process and it is assumed that the average value of the final diameter of the polycrystalline silicon rod is defined as D (mm) and the mutual interval between the multiple pairs of silicon cores is defined as L (mm).

FZ silicon which shows no degradation of its minority carrier lifetime after any processing steps at a processing temperature of less than 900 C. is prepared by annealing FZ silicon at an annealing temperature of greater than or equal to 900 C. and processing the annealed FZ silicon at a processing temperature of less than 900 C.

FZ silicon which shows no degradation of its minority carrier lifetime after any processing steps at a processing temperature of less than 900 C. is prepared by annealing FZ silicon at an annealing temperature of greater than or equal to 900 C. and processing the annealed FZ silicon at a processing temperature of less than 900 C.

Processes and systems to fabricate high throughput, low cost tubular polysilicon feed rods, which can be used as direct feedstock to grow a crystalline silicon material, are disclosed. In an example, a chemical vapor deposition (CVD) process includes depositing polysilicon on a tubular electrode to form a tubular polysilicon feed rod. The tubular polysilicon feed rod may be melted in a float zone process to grow the single-crystalline silicon material.

Processes and systems to fabricate high throughput, low cost tubular polysilicon feed rods, which can be used as direct feedstock to grow a crystalline silicon material, are disclosed. In an example, a chemical vapor deposition (CVD) process includes depositing polysilicon on a tubular electrode to form a tubular polysilicon feed rod. The tubular polysilicon feed rod may be melted in a float zone process to grow the single-crystalline silicon material.

A growing single crystal is supported in the region of a conical section of the single crystal via a supporting body during crystallization of the single crystal by the FZ method. The method comprises pressing the supporting body against the conical section of the growing single crystal at a temperature at which a first material of the supporting body becomes soft, and continuing pressing the supporting body against the conical section of the growing single crystal until the first material and a second material of the supporting body that remains hard at the cited temperature touch the conical section of the growing single crystal.

A growing single crystal is supported in the region of a conical section of the single crystal via a supporting body during crystallization of the single crystal by the FZ method. The method comprises pressing the supporting body against the conical section of the growing single crystal at a temperature at which a first material of the supporting body becomes soft, and continuing pressing the supporting body against the conical section of the growing single crystal until the first material and a second material of the supporting body that remains hard at the cited temperature touch the conical section of the growing single crystal.

When FZ single crystal silicon is produced from polycrystalline silicon, which is synthesized by the Siemens method followed by being subjected to thermal treatment and includes crystal grains having a Miller index plane <111> or <220> as a principal plane and grown by the thermal treatment, and in which the X-ray diffraction intensity from either of the Miller index planes <111> and <220> after the thermal treatment is 1.5 times or less the X-ray diffraction intensity before the thermal treatment, as raw material, disappearance of crystal lines in the step of forming an FZ single crystal is markedly prevented.