US 12,297,560 B2
Method for manufacturing monocrystalline silicon by the Czochralski process by pulling a first straight body having a first diameter and a second straight body having a second diameter larger than the first diameter
Takashi Izeki, Nagasaki (JP); and Yasuhito Narushima, Tokyo (JP)
Assigned to SUMCO CORPORATION, Tokyo (JP)
Appl. No. 17/788,568
Filed by SUMCO CORPORATION, Tokyo (JP)
PCT Filed Dec. 21, 2020, PCT No. PCT/JP2020/047639
§ 371(c)(1), (2) Date Jun. 23, 2022,
PCT Pub. No. WO2021/132136, PCT Pub. Date Jul. 1, 2021.
Claims priority of application No. 2019-233273 (JP), filed on Dec. 24, 2019.
Prior Publication US 2023/0031070 A1, Feb. 2, 2023
Int. Cl. C30B 15/20 (2006.01); C30B 15/04 (2006.01); C30B 15/22 (2006.01); C30B 29/06 (2006.01); C30B 29/66 (2006.01)
CPC C30B 29/06 (2013.01) [C30B 15/04 (2013.01); C30B 15/22 (2013.01); C30B 29/66 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A manufacturing method of monocrystalline silicon, comprising:
pulling up monocrystalline silicon from a dopant-added melt in which a volatile dopant is added to a silicon melt and growing the monocrystalline silicon according to Czochralski process, the monocrystalline silicon used for manufacturing a wafer, wherein:
the monocrystalline silicon comprises a shoulder, a straight body, and a tail that are sequentially connected, and
the straight body comprises: a first straight body having a first diameter;
and a second straight body provided closer to the shoulder than the first straight body is and having a second diameter larger than the first diameter by from 3.5% to 15%, and
a diameter of a wafer manufactured from the first straight body is identical to a diameter of a wafer manufactured from the second straight body;
setting a resistivity at a start point of the straight body connected to the shoulder to a first resistivity; and
subsequently, pulling up and growing the monocrystalline silicon to form the first straight body, and setting a resistivity at a start point of the first straight body to a second resistivity lower than the first resistivity.