US 12,221,718 B2
Systems and methods for controlling a gas dopant vaporization rate during a crystal growth process
Chieh Hu, Chiayi (TW); Hsien-Ta Tseng, Zhunan (TW); Chun-Sheng Wu, Hsinchu (TW); William Lynn Luter, St. Charles, MO (US); Liang-Chin Chen, Zhubei (TW); Sumeet Bhagavat, St. Charles, MO (US); Carissima Marie Hudson, St. Charles, 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 Oct. 13, 2022, as Appl. No. 18/046,319.
Prior Publication US 2024/0125004 A1, Apr. 18, 2024
Int. Cl. C30B 15/04 (2006.01); C30B 15/14 (2006.01); C30B 15/20 (2006.01); C30B 29/06 (2006.01)
CPC C30B 15/04 (2013.01) [C30B 15/14 (2013.01); C30B 15/20 (2013.01); C30B 29/06 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An ingot pulling apparatus for growing a doped single crystal silicon ingot, the apparatus comprising:
an outer housing defining an inner chamber;
a crucible disposed within the inner chamber for holding a silicon melt; and
a gas doping system for introducing dopant species into the melt, the gas doping system comprising:
a feed tube extending between a first end and a second end, the second end located in the inner chamber, the feed tube including a capsule disposed proximate the second end;
a dopant feed source coupled in flow communication with the first end of the feed tube, the dopant feed source being configured to add volatile dopant to the feed tube;
a positioning system configured to adjust the position of the feed tube between a first position, in which the second end of the feed tube is at a first height above a surface of the melt, and a second position, in which the second end of the feed tube is at a second height above the surface of the melt that is smaller than the first height; and
a controller communicatively coupled to the dopant feed source and the positioning system, the controller being configured to cause the dopant feed source to add a targeted amount of volatile dopant to the feed tube and to cause the positioning system to move the feed tube to the second position at a speed rate, each of the second height and the speed rate being selected to control a vaporization rate of the volatile dopant in the feed tube during an ingot pulling process.