US 12,351,937 B2
Production method for silicon monocrystal
Shogo Kobayashi, Tokyo (JP); Norihito Fukatsu, Tokyo (JP); Takahiro Kanehara, Tokyo (JP); and Hitomi Yamamoto, Tokyo (JP)
Assigned to SUMCO CORPORATION, Tokyo (JP)
Appl. No. 18/026,975
Filed by SUMCO Corporation, Tokyo (JP)
PCT Filed Sep. 21, 2021, PCT No. PCT/JP2021/034487
§ 371(c)(1), (2) Date Mar. 17, 2023,
PCT Pub. No. WO2022/071014, PCT Pub. Date Apr. 7, 2022.
Claims priority of application No. 2020-163638 (JP), filed on Sep. 29, 2020.
Prior Publication US 2023/0340691 A1, Oct. 26, 2023
Int. Cl. C30B 29/06 (2006.01); C30B 15/04 (2006.01); C30B 15/14 (2006.01)
CPC C30B 15/04 (2013.01) [C30B 15/14 (2013.01); C30B 29/06 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A manufacturing method of a silicon single crystal comprising:
generating a silicon melt containing a primary dopant; and
pulling up the silicon single crystal from the silicon melt,
wherein the pulling up of the silicon single silicon crystal comprises at least one additional doping process for adding a secondary dopant into the silicon melt,
a flow rate of Ar gas supplied to a pulling-up furnace during a first period in which the secondary dopant is not added is set as a first flow rate, and
the flow rate of Ar gas supplied to the pulling-up furnace during a second period that includes a period in which the secondary dopant is added is set as a second flow rate that is greater than the first flow rate;
wherein the at least one additional doping process increases the Ar gas flow rate to the second flow rate before beginning to add the secondary dopant, and restores the Ar gas flow rate to the first flow rate after addition of the secondary dopant ends.