A method for producing a silicon single crystal, wherein a silicon nitride powder is introduced into a raw material before start of melting and the silicon single crystal doped with nitrogen is pulled by Czochralski method, wherein nitrogen doping is performed while an upper limit amount of usable silicon nitride powder is limited based on an amount of carbon impurities contained in the silicon nitride powder so that a carbon concentration in the silicon single crystal is equal to or less than allowable value. This makes it possible to achieve the required nitrogen doping amount at low cost while achieving the low carbon-concentration specification.

A method for producing a silicon single crystal, wherein a silicon nitride powder is introduced into a raw material before start of melting and the silicon single crystal doped with nitrogen is pulled by Czochralski method, wherein nitrogen doping is performed while an upper limit amount of usable silicon nitride powder is limited based on an amount of carbon impurities contained in the silicon nitride powder so that a carbon concentration in the silicon single crystal is equal to or less than allowable value. This makes it possible to achieve the required nitrogen doping amount at low cost while achieving the low carbon-concentration specification.

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.

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.

An embodiment provides a method for manufacturing a silicon single crystal ingot by using a silicon single crystal growing apparatus comprising: a chamber; a crucible arranged inside the chamber and accommodating a molten silicon solution; a heater arranged outside the crucible so as to heat the crucible; a heat shielding part arranged inside the chamber; and a pulling part for pulling a single crystal growing from the molten silicon solution, wherein the method can comprise a step of respectively growing a neck part, a shoulder part and a body part.

An embodiment provides a method for manufacturing a silicon single crystal ingot by using a silicon single crystal growing apparatus comprising: a chamber; a crucible arranged inside the chamber and accommodating a molten silicon solution; a heater arranged outside the crucible so as to heat the crucible; a heat shielding part arranged inside the chamber; and a pulling part for pulling a single crystal growing from the molten silicon solution, wherein the method can comprise a step of respectively growing a neck part, a shoulder part and a body part.

A semiconductor wafer of single-crystal silicon has an oxygen concentration per new ASTM of not less than 5.0×10.sup.17 atoms/cm.sup.3 and not more than 6.5×10.sup.17 atoms/cm.sup.3; a nitrogen concentration per new ASTM of not less than 1.0×10.sup.13 atoms/cm.sup.3 and not more than 1.0×10.sup.14 atoms/cm.sup.3; a front side having a silicon epitaxial layer wherein the semiconductor wafer has BMDs whose mean size is not more than 10 nm determined by transmission electron microscopy and whose mean density adjacent to the epitaxial layer is not less than 1.0×10.sup.11 cm.sup.−3, determined by reactive ion etching after having subjected the wafer covered with the epitaxial layer to a heat treatment at a temperature of 780° C. for a period of 3 h and to a heat treatment at a temperature of 600° C. for a period of 10 h.

A mono-crystalline silicon growth apparatus is provided. The mono-crystalline silicon growth apparatus includes a furnace, a support base disposed in the furnace, a crucible disposed on the support base, and a heating module. The support base and the crucible do not rotate relative to the heating module, and an axial direction is defined to be along a central axis of the crucible. The heating module is disposed at an outer periphery of the support base and includes a first heating unit, a second heating unit, and a third heating unit. The first heating unit, the second heating unit, and the third heating unit are respectively disposed at positions with different heights corresponding to the axial direction.

A method for manufacturing a monocrystalline silicon with Czochralski process, including: providing polycrystalline silicon and dopant to quartz crucible in single crystal furnace and vacuumizing, melting the polycrystalline silicon under protective gas to obtain silicon melt; after temperature of the silicon melt is stable, immersing seed crystal into the silicon melt to start seeding, lifting a shield away from surface of the silicon melt to adjust distance between the shield and the silicon melt to first preset distance; after seeding, performing shouldering to pull the crystal to increase diameter of the crystal to preset width; starting constant-diameter body growth, lowering the shield towards the surface of the silicon melt to adjust the distance to second preset distance; after growth, entering a tailing stage during which the diameter of the crystal is reduced until the crystal is separated from the silicon melt; and cooling the crystal to obtain monocrystalline silicon.

A method for manufacturing a monocrystalline silicon with Czochralski process, including: providing polycrystalline silicon and dopant to quartz crucible in single crystal furnace and vacuumizing, melting the polycrystalline silicon under protective gas to obtain silicon melt; after temperature of the silicon melt is stable, immersing seed crystal into the silicon melt to start seeding, lifting a shield away from surface of the silicon melt to adjust distance between the shield and the silicon melt to first preset distance; after seeding, performing shouldering to pull the crystal to increase diameter of the crystal to preset width; starting constant-diameter body growth, lowering the shield towards the surface of the silicon melt to adjust the distance to second preset distance; after growth, entering a tailing stage during which the diameter of the crystal is reduced until the crystal is separated from the silicon melt; and cooling the crystal to obtain monocrystalline silicon.