US 12,435,440 B2
Methods for producing a single crystal silicon ingot using boric acid as a dopant
William L. Luter, St. Charles, MO (US); Hariprasad Sreedharamurthy, Ballwin, MO (US); Stephan Haringer, Kastelbell/Tschars (IT); Richard J. Phillips, St. Peters, MO (US); Nan Zhang, O'Fallon, MO (US); and Yu-Chiao Wu, Frontenac, MO (US)
Assigned to GlobalWafers Co., Ltd., Hsinchu (TW)
Filed by GlobalWafers Co., Ltd., Hsinchu (TW)
Filed on Jan. 9, 2023, as Appl. No. 18/151,989.
Application 18/151,989 is a division of application No. 16/875,468, filed on May 15, 2020, granted, now 11,585,010.
Claims priority of provisional application 62/868,573, filed on Jun. 28, 2019.
Prior Publication US 2023/0160093 A1, May 25, 2023
Int. Cl. C30B 15/04 (2006.01); C30B 15/10 (2006.01); C30B 15/14 (2006.01); C30B 29/06 (2006.01); C30B 35/00 (2006.01)
CPC C30B 15/04 (2013.01) [C30B 15/10 (2013.01); C30B 15/14 (2013.01); C30B 29/06 (2013.01); C30B 35/002 (2013.01); C30B 35/007 (2013.01); Y10T 117/00 (2015.01); Y10T 117/10 (2015.01)] 19 Claims
OG exemplary drawing
 
1. A method for producing a single crystal silicon ingot from a silicon melt held within a crucible in an ingot puller apparatus, the ingot puller apparatus having an outer housing, the method comprising:
adding polycrystalline silicon to the crucible, the crucible being disposed within an ingot puller inner chamber;
heating the polycrystalline silicon to cause the silicon melt to form in the crucible;
pulling the single crystal silicon ingot from the silicon melt;
providing a source of solid-phase boric acid;
producing a boron-containing gas from the solid-phase boric acid, wherein:
the boron-containing gas is produced from the solid-phase boric acid while the solid-phase boric acid is disposed exterior to the ingot puller outer housing; or
the boron-containing gas is produced from the solid-phase boric acid while the solid-phase boric acid is supported by a dopant receptacle disposed within a feed tube, wherein the source of solid-phase boric acid is added to the dopant receptacle when the dopant receptacle is in a loading position in which the dopant receptacle is disposed exterior to the ingot puller outer housing, the dopant receptacle being moved relative to the feed tube from the loading position to a feed position in which the dopant receptacle is disposed within the ingot puller inner chamber, the boron-containing gas being produced from the solid-phase boric acid while the dopant receptacle is in the feed position; and
contacting the boron-containing gas with a surface of the melt to cause boron to enter the melt as a dopant while pulling the single crystal silicon ingot from the melt.