Tokuyama Corporation

Tokuyama Corproation

Miki Emoto

Takuya Asano

Kouichi Saiki

Tooru Onoda

Junya Sakai

Makoto Kamada

Takamitsu Kamikawa

Seiji Katou

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.

Polycrystalline silicon rod and method for manufacturing same

A polycrystalline silicon material for producing silicon single crystal, containing a plurality of polycrystalline silicon chunks, in which assuming that a total concentration of donor elements present inside a bulk body of the polycrystalline silicon material is Cd1 [ppta], a total concentration of acceptor elements present inside the bulk body of the polycrystalline silicon material is Ca1 [ppta], a total concentration of the donor elements present on a surface of the polycrystalline silicon material is Cd2 [ppta], and a total concentration of the acceptor elements present on the surface of the polycrystalline silicon material is Ca2 [ppta], Cd1, Ca1, Cd2, and Ca2 satisfy a relation of 2 [ppta]≤(Cd1+Cd2)−(Ca1+Ca2)≤8 [ppta].

Polycrystalline silicon material

A silicon core wire for depositing polycrystalline silicon is formed in a gate shape and includes a pair of vertical rod portions and a horizontal portion laterally connecting upper ends of the vertical rod portions, in which ends of the vertical rod portions and the horizontal portion are joined by welding, and a corner junction has a surface metallic concentration of 1 ppbw or less, more specifically, with an iron concentration of 0.2 ppbw or less, a chromium concentration of 0.1 ppbw or less, a nickel concentration of 0.05 ppbw or less, and a titanium concentration of 0.2 ppbw or less.

Silicon core wire for depositing polycrystalline silicon and production method therefor

A polycrystalline silicon material for producing silicon single crystal, containing a plurality of polycrystalline silicon chunks, in which assuming that a total concentration of donor elements present inside a bulk body of the polycrystalline silicon material is Cd1 [ppta], a total concentration of acceptor elements present inside the bulk body of the polycrystalline silicon material is Ca1 [ppta], a total concentration of the donor elements present on a surface of the polycrystalline silicon material is Cd2 [ppta], and a total concentration of the acceptor elements present on the surface of the polycrystalline silicon material is Ca2 [ppta], Cd1, Ca1, Cd2, and Ca2 satisfy a relation of 5 [ppta]≤(Ca1+Ca2)−(Cd1+Cd2)≤26 [ppta].

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Yamaguchi, Japan

Miki Emoto