US 12,091,769 B2
Determination of mass/time ratios for buffer members used during growth of single crystal silicon ingots
Matteo Pannocchia, Lana (IT); Francesca Marchese, Merano (IT); and James Ho Wai Kitt, Lana (IT)
Assigned to GlobalWafers Co., Ltd., Hsinchu (TW)
Filed by GlobalWafers Co., Ltd., Hsinchu (TW)
Filed on Jan. 13, 2023, as Appl. No. 18/154,418.
Application 18/154,418 is a continuation of application No. 17/553,031, filed on Dec. 16, 2021, granted, now 11,767,610.
Claims priority of provisional application 63/132,713, filed on Dec. 31, 2020.
Claims priority of provisional application 63/132,712, filed on Dec. 31, 2020.
Prior Publication US 2023/0142420 A1, May 11, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. C30B 15/00 (2006.01); C30B 15/12 (2006.01); C30B 15/20 (2006.01); C30B 29/06 (2006.01)
CPC C30B 15/002 (2013.01) [C30B 15/12 (2013.01); C30B 15/20 (2013.01); C30B 29/06 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method for determining a threshold ratio of M/T for growing a single crystal silicon ingot in a continuous Czochralski process that includes forming a melt of silicon in a crucible assembly, adding a batch of quartz cullets to the melt with the batch having a mass M, contacting a surface of the melt with a seed crystal, withdrawing a single crystal silicon ingot from the melt, the single crystal silicon ingot comprising a main body, there being a time T between adding the batch of quartz cullets to the melt and start of growth of the main body, and adding solid polycrystalline silicon feedstock to the crucible assembly while withdrawing the single crystal silicon ingot to replenish the melt, the method comprising:
growing the plurality of single crystal silicon ingots with at least two of the ingots being grown with different ratios of M/T;
measuring a defect count in one or more wafers sliced from the plurality of single crystal silicon ingots; and
determining the ratio of M/T for single crystal silicon ingots from which wafers were sliced having a defect count below a threshold defect count.