Abstract: In the present invention, as a bag to store polycrystalline silicon ingots, there is used a bag in which the concentration of paraffinic hydrocarbons in a concentrate of solvent-soluble components obtained by Soxhlet extraction using acetone as a solvent is lower than 300 ppmw as a value measured by GC-MS method; the concentration of antioxidants, lower than 10 ppmw; the concentration of ultraviolet absorbents, lower than 5 ppmw; and the concentration of antistatic agents and surfactants, lower than 50 ppmw. Then, when the polycrystalline silicon ingots are packed, preferably, the polycrystalline silicon ingots are put in the storage bag; thereafter, the storage bag is sealed; further, the storage bag is put and sealed in a linear low-density polyethylene bag containing an antistatic agent or a surfactant added in the bag material.

Abstract: 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.

Abstract: 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.

Abstract: In the present invention, when polycrystalline silicon bar is manufactured by the Siemens method, polycrystalline silicon is deposited, for example, under the conditions that during performing the deposition reaction of polycrystalline silicon, the reaction temperature is set to fall within a range from 1100° C. to 1150° C. and the internal pressure of the furnace is controlled to fall within a range from 0.45 to 0.9 MPa. By controlling the internal pressure of the furnace so as to fall within such a range, it is possible to obtain a polycrystalline silicon bar having an average value of the crystal grain sizes of 6 ?m or less, based on the crystal grain sizes evaluated by the EBSD method in arbitrary portions.

Abstract: First, at least one of silanol and a siloxane compound is generated in a chlorosilane (S101). In the step, for example, an inert gas having a moisture concentration of 0.5 to 2.5 ppm is brought into contact with the chlorosilane to dissolve the moisture, and at least one of silanol and a siloxane compound is generated through a hydration reaction of a moiety of the chlorosilane. Next, a boron-containing compound contained in the chlorosilane is reacted with the silanol or the siloxane compound, thereby converting the boron-containing compound to a boron oxide (S102). Through the step (S102), the boron-containing compound being a low boiling point compound is converted to a boron oxide being a high boiling point compound, and therefore the difference in boiling point from the boiling point of chlorosilane becomes larger to make later separation easy.

Abstract: An average diffraction intensity ratio (y=(h1, k1, l1)/(h2, k2, l2)) for a rotation angle (?) is obtained from a first diffraction chart and a second diffraction chart, and a surface temperature during deposition is calculated based on this average diffraction intensity ratio. Based on data on the surface temperature of a polycrystalline silicon rod calculated and supplied current and applied voltage during the deposition of the polycrystalline silicon rod, the supplied current and the applied voltage when newly manufacturing a polycrystalline silicon rod is controlled to control a surface temperature during the deposition process. By using such a temperature control method, it is also possible to control the difference ?T (=Tc?Ts) between the center temperature Tc and the surface temperature Ts of a polycrystalline silicon rod during a deposition process to control the value of residual stress in the polycrystalline silicon rod.

Abstract: Plate-like samples each having as a principal plane thereof a cross section perpendicular to the long axis direction of a polycrystalline silicon rod grown by the deposition using a chemical vapor deposition method are sampled; an X-ray diffraction measurement is performed omnidirectionally in the plane of each of the plate-like samples thus sampled; and when none of the plate-like samples has any X-ray diffraction peak with a diffraction intensity deviating from the average value ±2×standard deviation (?±2?) found for any one of the Miller indices <111>, <220>, <311> and <400>, the polycrystalline silicon rod is selected as the raw material for use in the production of single-crystalline silicon. The use of such a polycrystalline silicon raw material suppresses the local occurrence of the portions remaining unmelted, and can contribute to the stable production of single-crystalline silicon.

Abstract: A polycrystalline silicon rod is synthesized by the Siemens method (S101). After the polycrystalline silicon rod is covered from above with a plastic bag whose inner surface has been washed, and housed in the plastic bag in a reactor (S103), the polycrystalline silicon rod is removed out of the reactor (S104), and heat-sealed and stored in an enclosed state (S105). According to the present invention, steps conventionally considered as essential, such as washing, etching, and water washing, are not always necessary, and therefore the concentrations of fluorine ions, nitrate ions, and nitrogen dioxide ions remaining on the surface can each be less than 0.2 ppbw. In addition, by covering with the plastic bag, the metal contamination levels decrease significantly. Moreover, when the handling according to the present invention is performed, surface contamination hardly proceeds even if the polycrystalline silicon rod is stored for a long period.

Abstract: In the present invention, once a polycrystalline silicon rod is grown by the Siemens process, the polycrystalline silicon rod is heat-treated within a temperature range from 750° C. to 900° C. to relieve residual stress in the crystal. According to the experiment of the present inventors, residual stress can be relieved satisfactorily by heat treatment at the above-described low temperature, and in addition, metal contamination cannot be induced and the physical properties of the polycrystalline silicon rod cannot be changed. The above heat treatment can be conducted inside a furnace used to grow the polycrystalline silicon rod, and can also be conducted outside a furnace used to grow the polycrystalline silicon rod. According to the present invention, a polycrystalline silicon rod with residual stress (?) of not more than +20 MPa evaluated by a 2?-sin2 ? diagram can be obtained.

Abstract: The method comprises following steps; a collected disk sample (20) is disposed at a position where Bragg reflection from a Miller index plane <hkl> is detected; the disk sample (20) is rotated in-plane about the center thereof by a rotation angle ? so that an X-ray irradiation region defined by a slit ?-scans the principal plane of the disk sample (20); a chart showing the dependence of intensity of the Bragg reflection on the rotation angle (?) of the disk sample (20) is determined; the amount of change per a unit rotation angle of diffraction intensity of a baseline of the ? scan chart is determined as a first derivative value; skewness in the normal distribution of the absolute value of the amount of change is calculated; and the skewness is used as an evaluation index of the crystal grain size distribution to select polycrystalline silicon.

Abstract: The present invention provides technology for realizing higher purification of a polycrystalline silicon. First, trichlorosilane is prepared as a sample (S101) and then the carbon-containing impurities content in the trichlorosilane is analyzed by GC/MS-SIM method (S102). The quality of the trichlorosilane is determined based on the analysis results (S103) and the trichlorosilane determined to be a good material (S103: Yes) is used as the raw material for producing a high-purity polycrystalline silicon by CVD method (104). In case, the trichlorosilane determined to be a bad material (S103: No) is not used as the raw material for producing a polycrystalline silicon. When the impurities analysis by GC/MS-SIM method is performed using, as a separation column, a column having a non-polar column and a medium-polar column connected in series with each other, it is possible to simultaneously perform both of the separation of chlorosilanes and hydrocarbons and the separation of chlorosilanes and methylsilanes.

Abstract: When a plate-like sample 20 extracted from a polycrystalline rod is evaluated, peaks can appear in a ?-scanning chart. The smaller the number of such peaks, and the narrower the half-value width of the peak, the more suitable the polycrystalline silicon rod is as a raw material for producing single-crystal silicon. It is preferable that the number of peaks in the ?-scanning chart is, for both the Miller index planes <111> and <220>, equal to or smaller than 24/cm2 when converted into unit per area of the plate-like sample. It is also preferable that the value obtained by multiplying the peak half-value width by ?L=21/2?R0/360, where R0 is the radius of the sample, is defined as an inhomogeneous crystal grain size, and that a polycrystalline silicon rod of which all the inhomogeneous crystal grain sizes are smaller than 0.5 mm is selected as a raw material for producing single-crystal silicon.

Abstract: The method for evaluating crystallinity of polycrystalline silicon includes: disposing a collected plate sample (20) at a position where Bragg reflection from a first Miller index plane <h1k1l1> is detected; rotating the plate sample (20) in-plane about the center thereof by a rotation angle ? so that an X-ray irradiation region defined by a slit ?-scans a principal plane of the plate sample (20); determining a chart showing the dependence of intensity of the Bragg reflection from the Miller index plane <hkl> on the rotation angle (?) of the plate sample (20); determining a diffraction intensity value (IB1) of a baseline from the chart; similarly determining a diffraction intensity value (IB2) of a baseline from a ? scan chart obtained from a second Miller index plane <h2k2l2>; and using size relation between the IB1 value and the IB2 value as an evaluation index of the crystallinity of polycrystalline silicon.

Abstract: When the degree of crystalline orientation of polycrystalline silicon is evaluated by an X-ray diffraction method, each obtained disc-like sample 20 is disposed in a position where Bragg reflection from a Miller index face <hkl> is detected and in-plane rotated at a rotational angle ? with the center of the disc-like sample 20 as the center of rotation, so that an X-ray-radiated region defined by a slit ?-scans over the principal surface of the disc-like sample 20, to determine a chart representing the dependence of the intensity of Bragg reflection from the Miller index face <hkl> on the rotational angle (?) of the disc-like sample 20, a baseline is determined from the chart, and the diffraction intensity value of the baseline is used as an estimative index of the degree of crystalline orientation.

Abstract: When the degree of crystalline orientation of polycrystalline silicon is evaluated by an X-ray diffraction method, each obtained disc-like sample 20 is disposed in a position where Bragg reflection from a Miller index face <hkl> is detected and in-plane rotated at a rotational angle ? with the center of the disc-like sample 20 as the center of rotation, so that an X-ray-radiated region defined by a slit ?-scans over the principal surface of the disc-like sample 20, to determine a chart representing the dependence of the intensity of Bragg reflection from the Miller index face <hkl> on the rotational angle (?) of the disc-like sample 20, a baseline is determined from the chart, and the diffraction intensity value of the baseline is used as an estimative index of the degree of crystalline orientation.

Abstract: The present invention provides technology for realizing higher purification of a polycrystalline silicon. First, trichlorosilane is prepared as a sample (S101) and then the carbon-containing impurities content in the trichlorosilane is analyzed by GC/MS-SIM method (S102). The quality of the trichlorosilane is determined based on the analysis results (S103) and the trichlorosilane determined to be a good material (S103: Yes) is used as the raw material for producing a high-purity polycrystalline silicon by CVD method (104). In case, the trichlorosilane determined to be a bad material (S103: No) is not used as the raw material for producing a polycrystalline silicon. When the impurities analysis by GC/MS-SIM method is performed using, as a separation column, a column having a non-polar column and a medium-polar column connected in series with each other, it is possible to simultaneously perform both of the separation of chlorosilanes and hydrocarbons and the separation of chlorosilanes and methylsilanes.

Abstract: When a plate-like sample 20 extracted from a polycrystalline rod is evaluated, peaks can appear in a ?-scanning chart. The smaller the number of such peaks, and the narrower the half-value width of the peak, the more suitable the polycrystalline silicon rod is as a raw material for producing single-crystal silicon. It is preferable that the number of peaks in the ?-scanning chart is, for both the Miller index planes <111> and <220>, equal to or smaller than 24/cm2 when converted into unit per area of the plate-like sample. It is also preferable that the value obtained by multiplying the peak half-value width by ?L=21/2?R0/360, where R0 is the radius of the sample, is defined as an inhomogeneous crystal grain size, and that a polycrystalline silicon rod of which all the inhomogeneous crystal grain sizes are smaller than 0.5 mm is selected as a raw material for producing single-crystal silicon.

Abstract: Plate-like samples each having as a principal plane thereof a cross section perpendicular to the long axis direction of a polycrystalline silicon rod grown by the deposition using a chemical vapor deposition method are sampled; an X-ray diffraction measurement is performed omnidirectionally in the plane of each of the plate-like samples thus sampled; and when none of the plate-like samples has any X-ray diffraction peak with a diffraction intensity deviating from the average value ±2×standard deviation (?±2?) found for any one of the Miller indices <111>, <220>, <311> and <400>, the polycrystalline silicon rod is selected as the raw material for use in the production of single-crystalline silicon. The use of such a polycrystalline silicon raw material suppresses the local occurrence of the portions remaining unmelted, and can contribute to the stable production of single-crystalline silicon.

Abstract: A silicon single crystal for use as semiconductor is grown by supplying, to a seed rod of single-crystal silicon, hydrochloride gas and silicon formed by admixing at least one chlorosilane gas selected from the group consisting of dichlorosilane, trichlorosilane and tetrachlorosilane with hydrogen gas at a high temperature to grow single-crystal silicon on the seed rod while etching the growing single-crystal silicon with the hydrochloride gas. The silicon single crystal is irradiated with laser rays so that the energy of the laser rays on the irradiated surface of the crystal ranges from 3100 to 3358 mW/cm.sup.2 and then spectra emitted by the crystal are optoelectrically determined to quantify the ultratrace elements present in the silicon single crystal. Moreover, the amounts of these ultratrace elements are reduced to those of ultratrace elements present in the chlorosilane gas.