According to the present invention, there is provided a polysilicon production apparatus including: a horizontal reaction tube having an inlet port through which gaseous raw materials including reactant gases and a reducing gas are supplied, an outlet port through which residual gases exit, a reaction surface with which the gaseous raw materials come into contact, and bottom openings through which molten polysilicon produced by the reactions of the gaseous raw materials is discharged; and first heating means adapted to heat the reaction surface of the horizontal reaction tube. The horizontal reaction tube includes reaction regions consisting of first reaction regions where polysilicon is deposited and second reaction regions where reaction by-products are converted to the reactant gases. The first reaction regions are connected in series with the second reaction regions. Also provided is a polysilicon production method using the polysilicon production apparatus.

According to the present invention, there is provided a polysilicon production apparatus including: a horizontal reaction tube having an inlet port through which gaseous raw materials including reactant gases and a reducing gas are supplied, an outlet port through which residual gases exit, a reaction surface with which the gaseous raw materials come into contact, and bottom openings through which molten polysilicon produced by the reactions of the gaseous raw materials is discharged; and first heating means adapted to heat the reaction surface of the horizontal reaction tube. The horizontal reaction tube includes reaction regions consisting of first reaction regions where polysilicon is deposited and second reaction regions where reaction by-products are converted to the reactant gases. The first reaction regions are connected in series with the second reaction regions. Also provided is a polysilicon production method using the polysilicon production apparatus.

When FZ single crystal silicon is produced from polycrystalline silicon, which is synthesized by the Siemens method followed by being subjected to thermal treatment and includes crystal grains having a Miller index plane <111> or <220> as a principal plane and grown by the thermal treatment, and in which the X-ray diffraction intensity from either of the Miller index planes <111> and <220> after the thermal treatment is 1.5 times or less the X-ray diffraction intensity before the thermal treatment, as raw material, disappearance of crystal lines in the step of forming an FZ single crystal is markedly prevented.

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).

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).

The deposition of polycrystalline silicon onto heated filament rods in a Siemens process is improved by supplying reaction gas at least partially through nozzles in the vertical wall of the deposition reactor, at an angle of 0° to 45° to the reactor wall, towards the base plate of the reactor.

The deposition of polycrystalline silicon onto heated filament rods in a Siemens process is improved by supplying reaction gas at least partially through nozzles in the vertical wall of the deposition reactor, at an angle of 0° to 45° to the reactor wall, towards the base plate of the reactor.

Installation of a shield around a Siemens reactor prior to harvesting polysilicon rods produced therein allows the upper, bell jar-like shell to be removed for cleaning, while protecting the polysilicon rods from contamination and increasing safety of nearby personnel. The polysilicon rods are harvested while the shield is present.

Installation of a shield around a Siemens reactor prior to harvesting polysilicon rods produced therein allows the upper, bell jar-like shell to be removed for cleaning, while protecting the polysilicon rods from contamination and increasing safety of nearby personnel. The polysilicon rods are harvested while the shield is present.

An object of the present invention is to provide a method for comparatively simply selecting polycrystalline silicon suitably used for stably producing single crystal silicon in high yield. According to the present invention, polycrystalline silicon having a maximum surface roughness (Peak-to-Valley) value Rpv of 5000 nm or less, an arithmetic average roughness value Ra of 600 nm or less and a root mean square roughness value Rq of 600 nm or less, the surface roughness values being measured by observing with an atomic force microscope (AFM) the surface of a collected plate-shaped sample, is selected as a raw material for producing single crystal silicon.