US 12,104,274 B2
Method and device for producing a single crystal of silicon, which single crystal is doped with n-type dopant
Wolfgang Staudacher, Munich (DE); and Georg Raming, Tann (DE)
Assigned to SILTRONIC AG, Munich (DE)
Appl. No. 17/784,742
Filed by SILTRONIC AG, Munich (DE)
PCT Filed Dec. 3, 2020, PCT No. PCT/EP2020/084390
§ 371(c)(1), (2) Date Jun. 13, 2022,
PCT Pub. No. WO2021/115904, PCT Pub. Date Jun. 17, 2021.
Claims priority of application No. 19216068 (EP), filed on Dec. 13, 2019.
Prior Publication US 2023/0332323 A1, Oct. 19, 2023
Int. Cl. C30B 15/04 (2006.01); C30B 15/10 (2006.01); C30B 15/26 (2006.01); C30B 29/06 (2006.01)
CPC C30B 15/04 (2013.01) [C30B 15/10 (2013.01); C30B 15/26 (2013.01); C30B 29/06 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A method for producing a single silicon crystal doped with n-type dopant and having a cylindrical portion with an electrical resistivity of not more than 2 mΩ·cm comprising:
pulling the single crystal by the CZ method from a melt contained in a crucible, and during the pulling of the cylindrical portion of the single crystal,
supplying a gas stream comprising gaseous dopant to a surface of the melt, the gas stream being guided from a sublimation facility outside a pulling chamber through a tubing system into the pulling chamber, and through a heat shield surrounding the growing single crystal or along an outer surface of the heat shield, to an annular channel on a lower end of the heat shield and from there through a plurality of nozzles to the surface of the melt,
ascertaining dopant consumption by a weighing cell, a camera with image processing, a flow meter, or combination thereof, located in a part of the tubing system which lies outside the pulling chamber, and
controlling a supply of dopant to the melt.