US 12,084,788 B2
Method for producing a silicon single crystal doped with nitrogen and having a controlled amount of carbon impurities
Kosei Sugawara, Nishigo-mura (JP); Ryoji Hoshi, Nishigo-mura (JP); and Tomohiko Ohta, Shirakawa (JP)
Assigned to SHIN-ETSU HANDOTAI CO., LTD., Tokyo (JP)
Appl. No. 17/794,039
Filed by SHIN-ETSU HANDOTAI CO., LTD., Tokyo (JP)
PCT Filed Dec. 1, 2020, PCT No. PCT/JP2020/044655
§ 371(c)(1), (2) Date Jul. 20, 2022,
PCT Pub. No. WO2021/166361, PCT Pub. Date Aug. 26, 2021.
Claims priority of application No. 2020-024862 (JP), filed on Feb. 18, 2020.
Prior Publication US 2023/0047427 A1, Feb. 16, 2023
Int. Cl. C30B 15/04 (2006.01); C30B 15/20 (2006.01); C30B 29/06 (2006.01)
CPC C30B 29/06 (2013.01) [C30B 15/04 (2013.01); C30B 15/20 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A method for producing a silicon single crystal, wherein a silicon nitride powder is introduced into a raw material before start of melting and the silicon single crystal doped with nitrogen is pulled by Czochralski method,
wherein nitrogen doping is performed while an upper limit amount of usable silicon nitride powder is set to satisfy a following formula (1):
{the upper limit amount [g]×(a carbon impurity concentration in the silicon nitride powder [wt. %]/100)/carbon atomic weight [g/mol]}/a charge amount [mol] of the silicon raw material≤0.32×10−6  (1).