Method for producing a single crystal from semiconductor material by the fz method; device for carrying out the method and semiconductor silicon wafer

A method for producing a single crystal of semiconductor material doped with dopant, comprising:

• creating a molten zone between a feed rod and a growing single crystal;
• melting material of the feed rod in a high frequency magnetic field of a first induction coil;
• crystallizing material of the molten zone on top of the growing single crystal;
• rotating the growing single crystal about an axis of rotation and changing the direction of rotation and the speed of rotation according to a predetermined pattern;
• and
• imposing an alternating magnetic field of a second induction coil on the molten zone, wherein the alternating magnetic field is not axisymmetric with respect to the axis of rotation of the growing single crystal.

A device for producing a single crystal of semiconductor material doped with dopant, comprising:

• a first induction coil for creating a molten zone between a feed rod and a growing single crystal;
• current leads to the first induction coil;
• and
• a second induction coil surrounding the growing single crystal and imposing an alternating magnetic field on said molten zone, said second induction coil being tilted from a horizontal plane.

A semiconductor wafer of single crystal silicon having a diameter 2R of at least 200 mm having an edge and doped with an n-type dopant, and comprising

• an interstitial oxygen concentration of not more than 1×1016 atoms/cm3;
• an increase in resistivity from a position R/2 to the edge of the semiconductor wafer of at least 2%, wherein R denotes the radius of the semiconductor wafer;
• a variation in resistivity expressed as RRV of not more than 9%;
• and
• striations with a fluctuation range of not more than ±10%.