Abstract: A reaction furnace for producing a polycrystalline silicon according to the present invention is designed so as to have an in-furnace reaction space in which a reaction space cross-sectional area ratio (S=[S0?SR]/SR) satisfies 2.5 or more, which is defined by an inner cross-sectional area (So) of a reaction furnace, which is perpendicular to a straight body portion of the reaction furnace, and a total sum (SR) of cross-sectional areas of polycrystalline silicon rods that are grown by precipitation of polycrystalline silicon, in a case where a diameter of the polycrystalline silicon rod is 140 mm or more. Such a reaction furnace has a sufficient in-furnace reaction space even when the diameter of the polycrystalline silicon rod has been expanded, and accordingly an appropriate circulation of a gas in the reaction furnace is kept.

Abstract: There is provided a method of manufacturing a polycrystalline silicon rod suitable as a raw material for manufacturing monocrystalline silicon by a FZ process. The method of manufacturing a polycrystalline silicon rod according to the present invention is a method of manufacturing a polycrystalline silicon rod by Siemens process, and includes a post-deposition energization step of, after an end of a deposition step of polycrystalline silicon, performing energization under a condition that provides a skin depth D shallower than a skin depth D0 provided at a time when the deposition step ends. For example, the post-deposition energization step is performed by passage of current at a frequency f higher than a frequency f0 of current that is passed at a time when the deposition step ends.

Abstract: A reactor 200 according to the present invention includes a heater storage section serving as a space section capable of accommodating a carbon heater to initial heating of silicon core wires. A carbon heater 13 is loaded in a deposition reaction space 20 in the reactor 200 only when necessary for initial heating of silicon core wires 12. After initial heating of the silicon core wires 12 is finished, the carbon heater 13 is unloaded from the deposition reaction space to the heater storage section 30. As a result, the carbon heater 13 is not unduly damaged in the reactor any longer and its deterioration is reduced. In addition, because of reduction in reaction with hydrogen gas in the reactor, the generation of methane is reduced, and thus carbon contamination of polycrystalline silicon is reduced.

Abstract: A reaction furnace for producing a polycrystalline silicon according to the present invention is designed so as to have an in-furnace reaction space in which a reaction space cross-sectional area ratio (S=[S0?SR]/SR) satisfies 2.5 or more, which is defined by an inner cross-sectional area (So) of a reaction furnace, which is perpendicular to a straight body portion of the reaction furnace, and a total sum (SR) of cross-sectional areas of polycrystalline silicon rods that are grown by precipitation of polycrystalline silicon, in a case where a diameter of the polycrystalline silicon rod is 140 mm or more. Such a reaction furnace has a sufficient in-furnace reaction space even when the diameter of the polycrystalline silicon rod has been expanded, and accordingly an appropriate circulation of a gas in the reaction furnace is kept.

Abstract: In the silicon core wire according to a first aspect of the present invention, a male thread part formed at one end of a first thin silicon rod and a female thread part formed at one end of a second thin silicon rod may be screwed together and fastened. In the silicon core wire according to a second aspect of the present invention, a thread part formed at one end of a first thin silicon rod and a thread part formed at one end of a second thin silicon rod may be screwed together and fastened via an adapter with thread parts formed at both ends.

Abstract: A polycrystalline silicon ingot having a value of Te?Ts, ?T, of 50° C. or less, wherein Ts and Te are the onset temperature and the completion temperature of melting, respectively, when the temperature is increased at a rate of 60° C./minute or less in the temperature range of 1400° C. or more is used as the production raw material for single crystal silicon. The present invention provides a polycrystalline silicon ingot or polycrystalline silicon rod suitable for stably producing single crystal silicon.

Abstract: An integrated sleeve structure is provided between an electrode configured to feed power to a silicon core wire and a bottom plate part. Sealing members are arranged on at least part of a flange part of an insulating member and on at least part of a straight part of the insulating member.

Abstract: An apparatus for producing polycrystalline silicon by the Siemens method, includes: a carbon-made core wire holder 14 holding a silicon core wire 13; an electrode portion 10 energizing the core wire holder 14, the electrode portion 10 having a top end 18 in contact with a bottom end of the core wire holder 14; and a first screwing section provided 17a only around a lower part of the core wire holder 14 to be fixed to the electrode portion 10, wherein the core wire holder 14 has a contact surface with the top end 18 of the electrode portion 10, the contact surface being lower in electric resistance than an area of the first screwing section 17a to be fastened.

Abstract: A reaction furnace for producing a polycrystalline silicon according to the present invention is designed so as to have an in-furnace reaction space in which a reaction space cross-sectional area ratio (S=[SO?SR]/SR) satisfies 2.5 or more, which is defined by an inner cross-sectional area (So) of a reaction furnace, which is perpendicular to a straight body portion of the reaction furnace, and a total sum (SR) of cross-sectional areas of polycrystalline silicon rods that are grown by precipitation of polycrystalline silicon, in a case where a diameter of the polycrystalline silicon rod is 140 mm or more. Such a reaction furnace has a sufficient in-furnace reaction space even when the diameter of the polycrystalline silicon rod has been expanded, and accordingly an appropriate circulation of a gas in the reaction furnace is kept.

Abstract: A reactor 200 according to the present invention includes a heater storage section serving as a space section capable of accommodating a carbon heater for initial heating of silicon core wires. A carbon heater 13 is loaded in a deposition reaction space 20 in the reactor 200 only when necessary for initial heating of silicon core wires 12. After initial heating of the silicon core wires 12 is finished, the carbon heater 13 is unloaded from the deposition reaction space to the heater storage section 30. As a result, the carbon heater 13 is not unduly damaged in the reactor any longer and its deterioration is reduced. In addition, because of reduction in reaction with hydrogen gas in the reactor, the generation of methane is reduced, and thus carbon contamination of polycrystalline silicon is reduced.

Abstract: In a step of performing cylindrical grinding of a polycrystalline silicon bar 10 grown by a Siemens method, this cylindrical grinding step is performed such that a polycrystalline silicon rod 30, whose center axis CR is shifted from a center axis C0 of a silicon core wire 20 by 2 mm or more, is manufactured.

Abstract: Provided is a polycrystalline silicon rod suitable as a raw material for production of single-crystalline silicon. A crystal piece (evaluation sample) is collected from a polycrystalline silicon rod grown by a Siemens method, and a polycrystalline silicon rod in which an area ratio of a crystal grain having a particle size of 100 nm or less is 3% or more is sorted out as the raw material for production of single-crystalline silicon. When single-crystalline silicon is grown by an FZ method using the polycrystalline silicon rod as a raw material, the occurrence of dislocation is remarkably suppressed.

Abstract: The present invention provides polycrystalline silicon suitably used as a raw material for producing single crystal silicon. The polycrystalline silicon rod of the present invention is a polycrystalline silicon rod grown by chemical vapor deposition performed under a pressure of 0.3 MPaG or more, wherein when a plate-shaped sample piece collected from an arbitrary portion of the polycrystalline silicon rod is observed with a microscope with a temperature increased from a temperature lower than a melting point of silicon up to a temperature exceeding the melting point of silicon, a heterogeneous crystal region, which is a crystal region including a plurality of crystal grains heterogeneously assembled and including no needle-like crystal, having a diameter exceeding 10 ?m is not observed.

Abstract: To provide polycrystalline silicon suitable as a raw material for production of single-crystalline silicon. A D/L value is set within the range of less than 0.40 when multiple pairs of silicon cores are placed in a reaction furnace in production of a polycrystalline silicon rod having a diameter of 150 mm or more by deposition according to a chemical vapor deposition process and it is assumed that the average value of the final diameter of the polycrystalline silicon rod is defined as D (mm) and the mutual interval between the multiple pairs of silicon cores is defined as L (mm).

Abstract: A reactor 200 according to the present invention includes a heater storage section serving as a space section capable of accommodating a carbon heater to initial heating of silicon core wires. A carbon heater 13 is loaded in a deposition reaction space 20 in the reactor 200 only when necessary for initial heating of silicon core wires 12. After initial heating of the silicon core wires 12 is finished, the carbon heater 13 is unloaded from the deposition reaction space to the heater storage section 30. As a result, the carbon heater 13 is not unduly damaged in the reactor any longer and its deterioration is reduced. In addition, because of reduction in reaction with hydrogen gas in the reactor, the generation of methane is reduced, and thus carbon contamination of polycrystalline silicon is reduced.

Abstract: A polycrystalline silicon ingot having a value of Te?Ts, ?T, of 50° C. or less, wherein Ts and Te are the onset temperature and the completion temperature of melting, respectively, when the temperature is increased at a rate of 60° C./minute or less in the temperature range of 1400° C. or more is used as the production raw material for single crystal silicon. The present invention provides a polycrystalline silicon ingot or polycrystalline silicon rod suitable for stably producing single crystal silicon.

Abstract: A reaction furnace for producing a polycrystalline silicon according to the present invention is designed so as to have an in-furnace reaction space in which a reaction space cross-sectional area ratio (S=[S0?SR]/SR) satisfies 2.5 or more, which is defined by an inner cross-sectional area (So) of a reaction furnace, which is perpendicular to a straight body portion of the reaction furnace, and a total sum (SR) of cross-sectional areas of polycrystalline silicon rods that are grown by precipitation of polycrystalline silicon, in a case where a diameter of the polycrystalline silicon rod is 140 mm or more. Such a reaction furnace has a sufficient in-furnace reaction space even when the diameter of the polycrystalline silicon rod has been expanded, and accordingly an appropriate circulation of a gas in the reaction furnace is kept.

Abstract: In order to obtain a polycrystalline silicon rod having an excellent shape, the placement relation between a source gas supplying nozzle 9 and metal electrodes 10 that are provided in a reactor is appropriately designed. The area of a disc-like base plate 5 is S0. An imaginary concentric circle C (radius c) centered at the center of the disc-like base plate 5 has an area S=S0/2. Further, a concentric circle A and a concentric circle B are imaginary concentric circles having the same center as that of the concentric circle C and having a radius a and a radius b, respectively (a<b<c). In the present invention, the electrode pairs 10 are placed inside of the imaginary concentric circle C and outside of the imaginary concentric circle B, and the gas supplying nozzle 9 is placed inside of the imaginary concentric circle A.

Abstract: The present invention provides a method of producing polycrystalline silicon in which silicon is precipitated on a silicon core wire to obtain a polycrystalline silicon rod. In an initial stage (former step) of a precipitation reaction, a reaction rate is not increased by supplying a large amount of source gas to a reactor but the reaction rate is increased by increasing a concentration of the source gas to be supplied, and in a latter step after the former step, the probability of occurrence of popcorn is reduced using an effect of high-speed forced convection caused by blowing the source gas into the reactor at high speed. Thus, a high-purity polycrystalline silicon rod with little popcorn can be produced without reducing production efficiency even in a reaction system with high pressure, high load, and high speed.

Abstract: Switches (S1-S3) allow switching between parallel/series configuration in a circuit (16) provided between two pairs of U-shaped silicon cores (12) arranged in a bell jar (1). In the circuit (16), current is supplied from one low-frequency power source (15L) supplying a low-frequency current, or from one high-frequency power source (15H) supplying a variable-frequency, high-frequency power source is used high-frequency current having a frequency of not less than 2 kHz. The two pairs of U-shaped silicon cores (12) are connected to each other in series by closing the switch (S1) and opening the switches (S2 and S3), and when the switch (S4) is switched to the side of the high-frequency power source (15H), and electric heating of the silicon cores (12) can be performed by supplying a high-frequency current having a frequency of less than 2 kHz to the series-connected U-shaped silicon cores (12) (or polycrystalline silicon rods (11)).