US 12,351,938 B2
Methods for producing a product ingot having low oxygen content
Carissima Marie Hudson, St. Charles, MO (US); JaeWoo Ryu, Chesterfield, MO (US); and HyungMin Lee, Cheonan-Si (KR)
Assigned to GlobalWafers Co., Ltd., Hsinchu (TW)
Filed by GlobalWafers Co., Ltd., Hsinchu (TW)
Filed on Jan. 10, 2023, as Appl. No. 18/152,544.
Claims priority of provisional application 63/308,877, filed on Feb. 10, 2022.
Prior Publication US 2023/0250550 A1, Aug. 10, 2023
Int. Cl. C30B 15/20 (2006.01); C30B 29/06 (2006.01); C30B 33/08 (2006.01)
CPC C30B 15/20 (2013.01) [C30B 29/06 (2013.01); C30B 33/08 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A method for producing a product ingot having an oxygen concentration of less than 5 ppma, the method comprising:
adding solid silicon to a crucible of a first ingot puller apparatus;
heating the solid silicon in the crucible of the first ingot puller apparatus to cause a first silicon melt to form in the crucible;
pulling a first sample rod from the first silicon melt, the first sample rod having a first sample rod diameter;
measuring an oxygen content of the first sample rod;
adding solid silicon to a crucible of a second ingot puller apparatus;
heating the solid silicon in the crucible of the second ingot puller apparatus to cause a second silicon melt to form in the crucible;
pulling a second sample rod from the second silicon melt, the second sample rod having a second sample rod diameter;
measuring an oxygen content of the second sample rod;
comparing the oxygen content of the first sample rod to the oxygen content of the second sample rod; and
growing the product ingot in the ingot puller apparatus in which the sample rod having a lower oxygen content was grown, the product ingot having a diameter, the first sample rod diameter and second sample rod diameter each being less than the diameter of the product ingot.