The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 23, 2025
Filed:
Aug. 20, 2020
Tokuyama Corporation, Yamaguchi, JP;
Tokuyama Corporation, Yamaguchi, JP;
Abstract
A method for producing a polycrystalline silicon rod includes: while energizing a core wire formed of silicon, supplying a polycrystalline silicon deposition raw material gas into a reactor so as to perform gas phase growth of polycrystalline silicon on a surface of the core wire, in which during a period from a completion of cleaning of the surface of the above core wire to an installation of the core wire in the reactor, the silicon core wire is placed in an atmosphere adjusted to a cleanliness of Class 4 to Class 6 as defined in ISO 14644-1. With this method, it is possible to obtain a polycrystalline silicon rod which has a total metal concentration of iron and nickel of 40 pptw or less in terms of elements in a region within 2 mm from an interface between the core wire and polycrystalline silicon deposited on the surface of the core wire.