US Patent No. 10,036,100

APPARATUS FOR PRODUCING SILICON SINGLE CRYSTAL


Patent No. 10,036,100
Issue Date July 31, 2018
Title Apparatus For Producing Silicon Single Crystal
Inventorship Takahiro Yanagimachi, Nishigo-mura (JP)
Masahiro Akiba, Nishigo-mura (JP)
Junya Tokue, Iwaki (JP)
Susumu Sonokawa, Nishigo-mura (JP)
Assignee SHIN-ETSU HANDOTAI CO., LTD., Tokyo (JP)

Claim of US Patent No. 10,036,100

1. An apparatus for producing a silicon single crystal based on a Czochralski method provided with a chamber having a heater therein to heat a raw material and cooling means to cool the chamber by a coolant, the apparatus comprising:measuring means for measuring an inlet temperature, an outlet temperature, and a flow rate in a passage of the coolant to cool the chamber with flowing in the chamber;
calculating means for calculating a removed heat quantity from the chamber on the basis of the measured values of the inlet temperature, the outlet temperature, and the flow rate; and
heater power-controlling means for controlling heater power on the basis of the calculated value of the removed heat quantity,
wherein the heater power-controlling means is provided with a function for calculating a pattern of set values of heater power in a straight body forming process in the next pulling, on the basis of operation result data of the removed heat quantity from the chamber obtained through pulling a silicon single crystal, and
the pattern of set values of heater power in a straight body forming process in the next pulling is calculated such that the set values of heater power is given feedback on pattern correction value “W” of heater power determined by the following equation:
W=Ws?(Ha?Hb)wherein, “W” represents the pattern correction value of heater power, Ws represents a heater power value at the start of the straight body forming process, Ha represents a removed heat quantity at the start of the straight body forming process, and Hb represents the calculated value of the removed heat quantity in the straight body forming process.