US 12,110,609 B2
Methods for forming a single crystal silicon ingot with reduced crucible erosion
Richard Joseph Phillips, St. Peters, MO (US); and Salvador Zepeda, St. Peters, MO (US)
Assigned to GlobalWafers Co., Ltd., Hsinchu (TW)
Filed by GlobalWafers Co., Ltd., Hsinchu (TW)
Filed on Jan. 20, 2021, as Appl. No. 17/152,993.
Claims priority of provisional application 63/112,431, filed on Nov. 11, 2020.
Prior Publication US 2022/0145491 A1, May 12, 2022
Int. Cl. C30B 15/10 (2006.01); C30B 15/30 (2006.01); C30B 29/06 (2006.01)
CPC C30B 15/10 (2013.01) [C30B 15/30 (2013.01); C30B 29/06 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method for forming a single crystal silicon ingot comprising:
adding solid-phase polycrystalline silicon to a crucible having a sidewall and a bottom;
heating the polycrystalline silicon to form a silicon melt having a surface;
contacting the silicon melt with a seed crystal;
withdrawing the seed crystal from the silicon melt to form a silicon ingot;
adding solid-phase synthetic quartz to the melt, the synthetic quartz being made by melting synthetic sand and extruding the melt of synthetic sand; and
at least partially dissolving the synthetic quartz, the synthetic quartz abutting the crucible sidewall at the surface of the melt when being dissolved, the surface of the melt being unobstructed between the ingot and the synthetic quartz, there being a gap between the synthetic quartz and ingot after addition of all synthetic quartz to the melt.