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: According to the present invention, a resin material that has the following surface concentration of impurities is consistently used in production of polycrystalline silicon. Values obtained from quantitative analysis by ICP-mass spectrometry using a 1 wt % nitric acid aqueous solution as an extraction liquid are: a phosphorous (P) concentration of 50 pptw or less; an arsenic (As) concentration of 2 pptw or less; a boron (B) concentration of 20 pptw or less; an aluminum (Al) concentration of 10 pptw or less; a total concentration of 6 elements of iron (Fe), chromium (Cr), nickel (Ni), copper (Cu), sodium (Na), and zinc (Zn) of 80 pptw or less; a total concentration of 10 elements of lithium (Li), potassium (K), calcium (Ca), titanium (Ti), manganese (Mn), cobalt (Co), molybdenum (Mo), tin (Sn), tungsten (W), and lead (Pb) of 100 pptw or less.

Abstract: For evaluating a polycrystalline silicon rod to be used as a raw material for production of FZ Si single crystals, novel evaluation values (values of characteristics×amount of crystals) including the amount of crystals grown in the growth direction (radial direction) are defined and the homogeneity in crystal characteristics in the growth direction (radial direction) is evaluated. Specifically, the homogeneity of the polycrystalline rod is evaluated by sampling a plurality of specimen plates each having, as a principal plane thereof, a cross-section perpendicular to a radial direction of the polycrystalline rod grown by a Siemens method at equal intervals in the radial direction, determining values of characteristics of the crystals of the specimen plates by measurements, and by using evaluation values obtained by multiplying amounts of the crystals (relative amounts of the crystals) at sites where the specimen plates have been sampled by the values of the crystal characteristics.

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: For evaluating a polycrystalline silicon rod to be used as a raw material for production of FZ Si single crystals, novel evaluation values (values of characteristics×amount of crystals) including the amount of crystals grown in the growth direction (radial direction) are defined and the homogeneity in crystal characteristics in the growth direction (radial direction) is evaluated. Specifically, the homogeneity of the polycrystalline rod is evaluated by sampling a plurality of specimen plates each having, as a principal plane thereof, a cross-section perpendicular to a radial direction of the polycrystalline rod grown by a Siemens method at equal intervals in the radial direction, determining values of characteristics of the crystals of the specimen plates by measurements, and by using evaluation values obtained by multiplying amounts of the crystals (relative amounts of the crystals) at sites where the specimen plates have been sampled by the values of the crystal characteristics.

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: For evaluating a polycrystalline silicon rod to be used as a raw material for production of FZ Si single crystals, novel evaluation values (values of characteristics×amount of crystals) including the amount of crystals grown in the growth direction (radial direction) are defined and the homogeneity in crystal characteristics in the growth direction (radial direction) is evaluated. Specifically, the homogeneity of the polycrystalline rod is evaluated by sampling a plurality of specimen plates each having, as a principal plane thereof, a cross-section perpendicular to a radial direction of the polycrystalline rod grown by a Siemens method at equal intervals in the radial direction, determining values of characteristics of the crystals of the specimen plates by measurements, and by using evaluation values obtained by multiplying amounts of the crystals (relative amounts of the crystals) at sites where the specimen plates have been sampled by the values of the crystal characteristics.

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 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: A plate-shaped sample with a cross-section perpendicular to a radial direction of a polycrystalline silicon rod as a principal surface is sampled from a region from a center (r=0) of the polycrystalline silicon rod to R/3. Then, the sample is disposed at a position at which a Bragg reflection from a (111) Miller index plane is detected. In-plane rotation with a rotational angle ? on the sample is performed with a center of the sample as a rotational center such that an X-ray irradiation region defined by a slit performs ?-scanning on the principal surface of the sample to obtain a diffraction chart indicating dependency of a Bragg reflection intensity from the (111) Miller index plane on a rotational angle of the sample. A ratio (Sp/St) between an area Sp of a peak part appearing in the diffraction chart and a total area St of the diffraction chart is calculated.

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: 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: 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: 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: 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: A polycrystalline silicon rod grown from monosilane as a raw material, having a crystal grain diameter in the range of 0.5 to 10 ?m, with an average grain diameter in the range of 2 to 3 ?m, as determined from an electron backscatter diffraction image obtained by irradiating a principal plane of a plate-like specimen collected from an arbitrary site with an electron beam, the principal plane being a cross-section perpendicular to the radial direction of the polycrystalline silicon rod, has a good FZ, L % value. The polycrystalline silicon rod further having a thermal diffusivity value measured on the principal plane of the plate-like specimen in the range of 75 to 85 mm2/sec at 25±1° C. has a good FZ, L % value and is suitable as a raw material for single crystallization.

Abstract: According to the present invention, a resin material that has the following surface concentration of impurities is consistently used in production of polycrystalline silicon. Values obtained from quantitative analysis by ICP-mass spectrometry using a 1 wt % nitric acid aqueous solution as an extraction liquid are: a phosphorous (P) concentration of 50 pptw or less; an arsenic (As) concentration of 2 pptw or less; a boron (B) concentration of 20 pptw or less; an aluminum (Al) concentration of 10 pptw or less; a total concentration of 6 elements of iron (Fe), chromium (Cr), nickel (Ni), copper (Cu), sodium (Na), and zinc (Zn) of 80 pptw or less; a total concentration of 10 elements of lithium (Li), potassium (K), calcium (Ca), titanium (Ti), manganese (Mn), cobalt (Co), molybdenum (Mo), tin (Sn), tungsten (W), and lead (Pb) of 100 pptw or less.

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 plate-shaped sample with a cross-section perpendicular to a radial direction of a polycrystalline silicon rod as a principal surface is sampled from a region from a center (r=0) of the polycrystalline silicon rod to R/3. Then, the sample is disposed at a position at which a Bragg reflection from a (111) Miller index plane is detected. In-plane rotation with a rotational angle ? on the sample is performed with a center of the sample as a rotational center such that an X-ray irradiation region defined by a slit performs ?-scanning on the principal surface of the sample to obtain a diffraction chart indicating dependency of a Bragg reflection intensity from the (111) Miller index plane on a rotational angle of the sample. A ratio (Sp/St) between an area Sp of a peak part appearing in the diffraction chart and a total area St of the diffraction chart is calculated.

Abstract: For evaluating a polycrystalline silicon rod to be used as a raw material for production of FZ Si single crystals, novel evaluation values (values of characteristics×amount of crystals) including the amount of crystals grown in the growth direction (radial direction) are defined and the homogeneity in crystal characteristics in the growth direction (radial direction) is evaluated. Specifically, the homogeneity of the polycrystalline rod is evaluated by sampling a plurality of specimen plates each having, as a principal plane thereof, a cross-section perpendicular to a radial direction of the polycrystalline rod grown by a Siemens method at equal intervals in the radial direction, determining values of characteristics of the crystals of the specimen plates by measurements, and by using evaluation values obtained by multiplying amounts of the crystals (relative amounts of the crystals) at sites where the specimen plates have been sampled by the values of the crystal characteristics.