A method produces semiconductor wafers of monocrystalline silicon. The method includes: pulling a cylindrical section of a single silicon crystal from a melt contained in a crucible, wherein the oxygen concentration in the cylindrical section is not more than 5×10.sup.17 atoms/cm.sup.3; subjecting the melt to a horizontal magnetic field; rotating the crucible at a rotational velocity and in a rotational direction during the pulling of the cylindrical section of the single crystal; and removing the semiconductor wafers of monocrystalline silicon from the cylindrical section of the single crystal. An amount of rotational velocity, averaged over time, is less than 1 rpm and the rotational direction is changed continually and the amplitude of the rotational velocity before and after the change in the rotational direction is not less than 0.5 rpm and not more than 3.0 rpm.

A method produces semiconductor wafers of monocrystalline silicon. The method includes: pulling a cylindrical section of a single silicon crystal from a melt contained in a crucible, wherein the oxygen concentration in the cylindrical section is not more than 5×10.sup.17 atoms/cm.sup.3; subjecting the melt to a horizontal magnetic field; rotating the crucible at a rotational velocity and in a rotational direction during the pulling of the cylindrical section of the single crystal; and removing the semiconductor wafers of monocrystalline silicon from the cylindrical section of the single crystal. An amount of rotational velocity, averaged over time, is less than 1 rpm and the rotational direction is changed continually and the amplitude of the rotational velocity before and after the change in the rotational direction is not less than 0.5 rpm and not more than 3.0 rpm.

Single silicon crystals having a resistivity of ≤20 mΩcm are pulled by the Czochralski process from a melt, by a method of pulling a first section of a neck at a first velocity whereby the diameter of a first section of the neck, with respect to the diameter of a seed crystal, tapers at a rate of ≤0.3 mm per mm neck length to a diameter of not more than 5 mm; pulling a second section of the neck at a pulling velocity of <0.2 mm/min for not less than 3 min, without the diameter increasing to more than 5.5 mm; and pulling a third section of the neck at a third pulling velocity of >2 mm/min.

Methods for growing a single crystal silicon ingot are disclosed. A dynamic state chart that monitors a plurality of ingot growth parameters may be produced and used during production of single crystal silicon ingots. In some embodiments, the dynamic state chart is a dynamic circle map chart having a plurality of sectors with each sector monitoring an ingot growth parameter.

Methods for growing a single crystal silicon ingot are disclosed. A dynamic state chart that monitors a plurality of ingot growth parameters may be produced and used during production of single crystal silicon ingots. In some embodiments, the dynamic state chart is a dynamic circle map chart having a plurality of sectors with each sector monitoring an ingot growth parameter.

A seeding method for crystal growth comprising: a first seeding step: rotating a crucible with a first rotation speed to grow the crystal to a first length; a second seeding step: gradually increasing the rotation speed of the crucible from the first rotation speed to a second rotation speed, and growing the crystal to a second length; a third seeding step: rotating the crucible with the second rotation speed to growing the crystal to a predicted length. By separating the seeding stage to three steps and gradually increasing the rotation speed in the second step of the crucible, the silicon melt convection is enhanced and the temperature at center of the silicon melt is kept to be not lower than the starting temperature of the seeding. Thereby, the removal of dislocation within the seed crystal can be increased, and the growth problems such as broken or polycrystallization can be prevented.

A seeding method for crystal growth comprising: a first seeding step: rotating a crucible with a first rotation speed to grow the crystal to a first length; a second seeding step: gradually increasing the rotation speed of the crucible from the first rotation speed to a second rotation speed, and growing the crystal to a second length; a third seeding step: rotating the crucible with the second rotation speed to growing the crystal to a predicted length. By separating the seeding stage to three steps and gradually increasing the rotation speed in the second step of the crucible, the silicon melt convection is enhanced and the temperature at center of the silicon melt is kept to be not lower than the starting temperature of the seeding. Thereby, the removal of dislocation within the seed crystal can be increased, and the growth problems such as broken or polycrystallization can be prevented.

A lift arm can be rotatably mounted to a crystal growing apparatus to service a hot-zone of the crystal growing apparatus. A low-speed, high-power lift arm actuator can control vertical positioning of the lift arm. Movable clamp arms secured to the lift arm can engage a lip of a furnace tank to facilitate lifting and moving the furnace tank to a desired location by correlated raising, lowering, or rotating of the lift arm. A winch mounted to a distal end of the lift arm can control spooling of a cable that passes through an interior of the lift arm and out an opening between the clamp arms. The cable can include an attachment mechanism for coupling to a crucible. The winch can thus lift the crucible at vertical speeds far in excess of the lift arm actuator's vertical speed.

A lift arm can be rotatably mounted to a crystal growing apparatus to service a hot-zone of the crystal growing apparatus. A low-speed, high-power lift arm actuator can control vertical positioning of the lift arm. Movable clamp arms secured to the lift arm can engage a lip of a furnace tank to facilitate lifting and moving the furnace tank to a desired location by correlated raising, lowering, or rotating of the lift arm. A winch mounted to a distal end of the lift arm can control spooling of a cable that passes through an interior of the lift arm and out an opening between the clamp arms. The cable can include an attachment mechanism for coupling to a crucible. The winch can thus lift the crucible at vertical speeds far in excess of the lift arm actuator's vertical speed.

A method for pulling a cylindrical crystal from a melt by a crystal pulling unit includes measuring an actual value of a diameter of the crystal at a surface of the melt, comparing the actual value with a setpoint value for the diameter of the crystal, and setting a height of the annular gap as a function of a deviation between the actual value and the setpoint value using a first controller which has a first readjustment time.