US 11,866,844 B2
Methods for producing a single crystal silicon ingot using a vaporized dopant
Yu-Chiao Wu, Frontenac, MO (US); William Lynn Luter, St. Charles, MO (US); Richard J. Phillips, St. Peters, MO (US); and James Dean Eoff, Montgomery City, MO (US)
Assigned to GlobalWafers Co., Ltd., Hsinchu (TW)
Filed by GlobalWafers Co., Ltd., Hsinchu (TW)
Filed on Dec. 31, 2020, as Appl. No. 17/139,352.
Prior Publication US 2022/0205131 A1, Jun. 30, 2022
Int. Cl. C30B 15/04 (2006.01); C30B 15/14 (2006.01)
CPC C30B 15/04 (2013.01) [C30B 15/14 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method for doping a single crystal silicon ingot pulled from a silicon melt held within a crucible positioned within an ingot puller apparatus, the ingot puller apparatus includes a housing, a dopant injector extending into the housing, and a heating system positioned with the housing, the dopant injector including a feed tube positioned within the housing and a vaporization cup positioned within the feed tube and the housing, the method comprising:
heating the vaporization cup using the heating system;
maintaining a pressure within the housing and the feed tube at a first pressure;
injecting liquid dopant into the feed tube and the vaporization cup, wherein a pressure of the liquid dopant is maintained at a second pressure greater than the first pressure prior to injection into the feed tube and the vaporization cup;
vaporizing the liquid dopant into vaporized dopant within the feed tube, wherein the liquid dopant is vaporized by flash evaporation by heating the liquid dopant with the vaporization cup and reducing the pressure of the liquid dopant from the second pressure to the first pressure by injecting the liquid dopant into the feed tube; and
channeling the vaporized dopant towards the silicon melt using the feed tube.