Abstract: After adding phosphorus (P) and germanium (Ge) into a silicon melt or adding phosphorus into a silicon/germanium melt, a silicon monocrystal is grown from the silicon melt by a Czochralski method, where a phosphorus concentration [P]L (atoms/cm3) in the silicon melt, a Ge concentration in the silicon monocrystal, an average temperature gradient Gave (K/mm) and a pull speed V (mm/min) are controlled to satisfy a formula (1) as follows, the phosphorus concentration [P] (atoms/cm3) in the silicon monocrystal is 4.84×1019 atoms/cm3 or more and 8.49×1019 atoms/cm3 or less, and the phosphorus concentration [P] (atoms/cm3) and the Ge concentration [Ge] (atoms/cm3) in the silicon monocrystal satisfy a relationship according to a formula (2) as follows while growing the silicon monocrystal. [P]L+(0.3151×[Ge]+3.806×1018)/1.5<0.5×(Gave/V+43)×1019??(1) [Ge]<?6.95×[P]+5.90×1020??(2).

Abstract: The sublimation speed of dopant can be precisely controlled without being influenced by a change over time of intra-furnace thermal environment. A dopant supply unit equipped with an accommodation chamber and a supply tube is provided. A sublimable dopant is accommodated. Upon sublimation of the dopant within the accommodation chamber, the sublimed dopant is introduced into a melt. The dopant within the accommodation chamber of the dopant supply unit is heated. The amount of heating by means of heating means is controlled so as to sublime the dopant at a desired sublimation speed. The dopant is supplied to the melt so that the dopant concentration until the first half of a straight body portion of the silicon single crystal is in the state of low concentration or non-addition.

Abstract: For manufacturing a monocrystal, a monocrystal pulling-up device controls pressure within a flow straightening cylinder to be from 33331 Pa to 79993 Pa and a flow velocity of inert gas in the cylinder to be from 0.06 m/sec to 0.31 m/sec (0.005 to 0.056 SL/min·cm2) during a post-addition-pre-growth period. By controlling the flow velocity of the inert gas to be in the above-described range during the post-addition-pre-growth period, the inert gas flows smoothly even when the pressure within the cylinder is relatively high. Evaporation of a volatile dopant because of a reverse flow of the inert gas can be restrained. The volatile dopant can be prevented from adhering to the flow straightening cylinder in an amorphous state, and the volatile dopant can be prevented from dropping into a melt or sticking on the melt while growing a crystal. Foulings can be easily removed.

Abstract: To provide a manufacturing method for a silicon single crystal that can reduce introduction of dislocation thereinto even if a required amount of dopant is added to a melt while growing a straight body portion of a silicon ingot. In a manufacturing method for a silicon single crystal according to the present invention that includes a dopant addition step of adding a dopant to a melt while a straight body portion of a silicon single crystal is growing in a growth step of growing the silicon single crystal by dipping a seed crystal into a silicon melt and then pulling the seed crystal therefrom, in the dopant addition step, a remaining mass of the melt is calculated at the beginning thereof, and the dopant is added to the melt at a rate of 0.01 to 0.035 g/min·kg per minute per 1 kg of the calculated remaining mass of the melt.

Abstract: A dopant device includes: a dopant holder that holds Ge which is solid at normal temperature and liquefies the Ge near a surface of the semiconductor melt, the dopant holder including a communicating hole for delivering the liquefied Ge downwardly; a cover portion for covering the Ge held by the dopant holder; and a vent provided on the cover portion for communicating with the outside. A dopant injecting method is carried out using such a dopant device, the dopant injecting method including: loading Ge dopant in a solid state into the doping device; liquefying the solid Ge dopant loaded into the doping device while holding the doping device at a predetermined height from a surface of a semiconductor melt; and doping the semiconductor melt with the liquefied Ge that is flowed from the communicating hole.

Abstract: In growing a silicon monocrystal from a silicon melt added with an N-type dopant by Czochralski method, the monocrystal is grown such that a relationship represented by a formula (1) as follows is satisfied. In the formula (1): a dopant concentration in the silicon melt is represented by C (atoms/cm3); an average temperature gradient of the grown monocrystal is represented by Gave(K/mm); a pulling-up speed is represented by V (mm/min); and a coefficient corresponding to a kind of the dopant is represented by A. By growing the silicon monocrystal under a condition shown in the left to a critical line G1, occurrence of abnormal growth due to compositional supercooling can be prevented.

Abstract: In consideration of influence of segregation, an evaporation area of a volatile dopant and influence of a pulling-up speed at the time of manufacturing a monocrystal by use of a monocrystal pulling-up device, an evaporation speed formula for calculating an evaporation speed of the dopant is derived. At a predetermined timing during pulling-up, gas flow volume and inner pressure in a chamber are controlled such that a cumulative evaporation amount of the dopant, calculated based on the evaporation speed formula, becomes a predetermined amount. A difference between a resistivity profile of the monocrystal predicted based on the evaporation speed formula and an actual resistivity profile is made small. Since no volatile dopant is subsequently added, increase in workload on an operator, increase of manufacturing time, an increase in amorphous adhering to the inside of the chamber, and an increase in workload at the time of cleaning the inside of the chamber can be prevented.

Abstract: Using a pulling-up apparatus, an oxygen concentration of the monocrystal at a predetermined position in a pulling-up direction is controlled based on a relationship in which the oxygen concentration of the monocrystal is decreased as a flow rate of the inactive gas at a position directly above a free surface of the dopant-added melt is increased when the monocrystal is manufactured with a gas flow volume in the chamber being in the range of 40 L/min to 400 L/min and an inner pressure in the chamber being in the range of 5332 Pa to 79980 Pa. Based on the relationship, oxygen concentration is elevated to manufacture the monocrystal having a desirable oxygen concentration. Because the oxygen concentration is controlled under a condition corresponding to a condition where the gas flow rate is rather slow, the difference between a desirable oxygen concentration profile of the monocrystal and an actual oxygen concentration profile is reduced.

Abstract: A doping device includes a first dopant accommodating portion including an opening on an upper portion to accommodate a first dopant that is evaporated near a surface of a semiconductor melt; a second dopant accommodating portion including a dopant holder that holds a second dopant that is liquefied near the surface of the semiconductor melt while including a communicating hole for delivering the liquefied dopant downwardly, and a conduit tube provided on a lower portion of the dopant holder for delivering the liquefied dopant flowed from the communicating hole to the surface of the semiconductor melt; and a guide provided by a cylinder body of which a lower end is opened and an upper end is closed for guiding dopant gas generated by evaporation of the first dopant to the surface of the semiconductor melt.

Abstract: In a dopant-injecting method for injecting a volatile dopant into a semiconductor melt, a doping device having an accommodating portion for accommodating a solid dopant and a cylindrical portion into which a gas ejected from the accommodating portion is introduced, a lower end surface of the cylindrical portion being opened to guide the gas to the melt, is used. The sublimation rate of the dopant in the accommodating portion is set in a range from 10 g/min to 50 g/min. Since a flow volume of the volatilized dopant gas is controlled by setting the sublimation rate of the dopant gas in the accommodating portion in the range from 10 g/min to 50 g/min, the melt is not blown off when the gas is blown onto the melt.

Abstract: According to an dopant-injection method for injecting volatilized dopant gas into semiconductor melt in a crucible (31), the crucible (31) is rotated alternately clockwise and counterclockwise around a support shaft (36) extending in a flowing direction of the dopant gas, so that the dopant gas is blown against the semiconductor melt white the crucible is rotated. Rotating the crucible (31) causes convection currents in the semiconductor melt therein, thereby facilitating diffusion of the blown dopant in the semiconductor melt.

Abstract: A graphite member utilized in a pulling device for pulling a silicon single crystal is provided. An edge part of the graphite member is rounded off which is exposed to a reactive gas. The graphite member may comprise: a plate part having a thickness of ‘t’ wherein a curvature radius of ‘r’ satisfies the formula: t/8?r?t/4.