A magnet coil for magnetic Czochralski single crystal growth includes: a first coil, a second coil, and an auxiliary coil arranged between the first coil and the second coil. A distance between the first coil and a first edge of the auxiliary coil close to the first coil is equal to a distance between the second coil and a second edge of the auxiliary coil close to the second coil. The auxiliary coil, the first coil and the second coil have a common central axis. When being energized, a direction of a current in the first coil is opposite to a direction of a current in the second coil, and a magnetic field generated by a current in the auxiliary coil is used for enhancing a cusp magnetic field between the first coil and the second coil.

In a producing method of an n-type monocrystalline silicon by pulling up a monocrystalline silicon from a silicon melt containing a main dopant in a form of red phosphorus to grow the monocrystalline silicon, the monocrystalline silicon exhibiting an electrical resistivity ranging from 0.5 mΩcm to 1.0 mΩcm is pulled up using a quartz crucible whose inner diameter ranges from 1.7-fold to 2.3-fold relative to a straight-body diameter of the monocrystalline silicon.

Method for producing a silicon ingot in which a horizontal magnetic field is generated are disclosed. A plurality of process parameters are regulated during ingot growth including a wall temperature of the crucible, a transport of silicon monoxide (SiO) from the crucible to the single crystal, and an evaporation rate of SiO from the melt. Regulating the plurality of process parameters may include controlling the position of a maximum gauss plane of the horizontal magnetic field, controlling the strength of the horizontal magnetic field, and controlling the crucible rotation rate.

A semiconductor wafer including a single crystal doped with a dopant, wherein a resistivity of the wafer is 0.7 mΩ-cm or less, and wherein a striation height of the wafer is 6 mm or more. The resistivity of the wafer may be 0.8 mΩ-cm or less, and the striation height may be 13 mm or more. The resistivity of the wafer may be 0.7 mΩ-cm or less, and the striation may be 22 mm or more. Example features relate to a method of making a semiconductor wafer that includes adding a dopant to a silicon melt, rotationally pulling a crystal from the silicon melt, and applying a magnetic field of 3000 G or more such that the semiconductor wafer has a resistivity that is equal to or less than 0.8 mΩ-cm and a striation height that is equal to or more than 13 mm.

A method for preparing a single crystal silicon ingot and a wafer sliced therefrom are provided. The ingots and wafers comprise nitrogen at a concentration of at least about 1×10.sup.14 atoms/cm.sup.3 and/or germanium at a concentration of at least about 1×10.sup.19 atoms/cm.sup.3, interstitial oxygen at a concentration of less than about 6 ppma, and a resistivity of at least about 1000 ohm cm.

A single-crystal pulling apparatus including: a pulling furnace having a central axis; and a magnetic field generation device arranged around the pulling furnace and having superconducting coils, the apparatus applying a horizontal magnetic field to the molten semiconductor raw material, two coil axes in the two pairs of the superconducting coils are included in a single horizontal plane, and when a direction of lines of magnetic force at the central axis of the pulling furnace in the horizontal plane is determined as an X axis, a center angle α having the X axis between the two coil axes is 100 degrees or more and 120 degrees or less. This makes it possible to reduce the height of the coils, to raise the magnetic field center close to the melt surface of the semiconductor raw material, and to obtain a single crystal having a lower oxygen concentration than conventional single crystals.

A method for growing a single crystal silicon ingot by the continuous Czochralski method is disclosed. The melt depth and thermal conditions are constant during growth because the silicon melt is continuously replenished as it is consumed, and the crucible location is fixed. The critical v/G is determined by the hot zone configuration, and the continuous replenishment of silicon to the melt during growth enables growth of the ingot at a constant pull rate consistent with the critical v/G during growth of a substantial portion of the main body of the ingot. The continuous replenishment of silicon is accompanied by periodic or continuous nitrogen addition to the melt to result in a nitrogen doped ingot.

A method for growing a single crystal silicon ingot by the continuous Czochralski method is disclosed. The melt depth and thermal conditions are constant during growth because the silicon melt is continuously replenished as it is consumed, and the crucible location is fixed. The critical v/G is determined by the hot zone configuration, and the continuous replenishment of silicon to the melt during growth enables growth of the ingot at a constant pull rate consistent with the critical v/G during growth of a substantial portion of the main body of the ingot. The continuous replenishment of silicon is accompanied by periodic or continuous nitrogen addition to the melt to result in a nitrogen doped ingot.

The present invention is a single-crystal pulling apparatus including: a pulling furnace which has a heater and a crucible arranged and which has a central axis; and a magnetic field generation device having superconducting coils, where the magnetic field generation device has four of the superconducting coils, two of the superconducting coils are arranged in each of two regions divided by a cross section that includes an X axis, the X axis being a direction of lines of magnetic force at the central axis in the horizontal plane including all the coil axes of the four superconducting coils, and includes the central axis of the pulling furnace so as to have line symmetry about the cross section, the four superconducting coils are all arranged so that the coil axes have an angle within a range of more than −30° and less than 30° relative to a Y axis, the direction of the lines of magnetic force thereof have line symmetry about the cross section, and in each of the regions, the two superconducting coils generate lines of magnetic force in opposite directions. This provides a single-crystal pulling apparatus with which there is no need to move the magnetic field generation device when dismantling and setting up the single-crystal pulling apparatus, and the oxygen concentration in the single crystal to be grown can be reduced, and at the same time, growth striations in the single crystal to be grown can be suppressed.

A method of controlling a convection pattern of a silicon melt includes applying a horizontal magnetic field having an intensity of 0.2 tesla or more to the silicon melt in a rotating quartz crucible to fix a direction of a convection flow in a plane orthogonal to an application direction of the horizontal magnetic field in the silicon melt, the horizontal magnetic field being applied so that a central magnetic field line passes through a point horizontally offset from a center axis of the quartz crucible by 10 mm or more.