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.

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 method for manufacturing an FZ silicon single crystal for a solar cell, including the steps of: pulling a CZ silicon single crystal doped with gallium by a Czochralski method; and float-zone processing a raw material rod, with the raw material rod being the CZ silicon single crystal, at 1.6 atmospheric pressure or more to manufacture the FZ silicon single crystal. As a result, it is possible to provide a method for manufacturing an FZ silicon single crystal for a solar cell that can decrease the amount of gallium dopant evaporated during the float-zone processing, thereby preventing the silicon single crystal from increasing the resistance while decreasing oxygen, which is inevitably introduced into a CZ crystal, and preventing formation of a B-O pair, which causes a problem to the characteristics of a solar cell.

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.

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 manufacturing method of a monocrystal includes: a shoulder-formation step to form a shoulder of the monocrystal; and a straight-body-formation step to form a straight body of the monocrystal, in which, in the shoulder-formation step, providing that a distance from a lowermost portion inside the crucible to a top surface of the dopant-added melt is defined as H (mm) and a radius of the top surface of the dopant-added melt is defined as R (mm), the shoulder starts to be formed in a condition that a relationship of 0.4<H/R<0.78 is satisfied.

A manufacturing method of a monocrystal includes: a shoulder-formation step to form a shoulder of the monocrystal; and a straight-body-formation step to form a straight body of the monocrystal, in which, in the shoulder-formation step, providing that a distance from a lowermost portion inside the crucible to a top surface of the dopant-added melt is defined as H (mm) and a radius of the top surface of the dopant-added melt is defined as R (mm), the shoulder starts to be formed in a condition that a relationship of 0.4<H/R<0.78 is satisfied.

Additive feed systems for feeding at least two different additives to silicon disposed within a crucible of an ingot puller apparatus are disclosed. The additive feed system may include first and second feed trays which are caused to vibrate to move first or second additive from a canister in which the additive is stored to another vessel in which the amount of first or second additive added to the vessel is sensed. The additive is discharged from the vessel into an additive feed tube through which the additive enters the crucible.

Additive feed systems for feeding at least two different additives to silicon disposed within a crucible of an ingot puller apparatus are disclosed. The additive feed system may include first and second feed trays which are caused to vibrate to move first or second additive from a canister in which the additive is stored to another vessel in which the amount of first or second additive added to the vessel is sensed. The additive is discharged from the vessel into an additive feed tube through which the additive enters the crucible.