Abstract: Single crystals of semiconductor material are produced by an FZ method, wherein a molten zone is created between a feed rod and a growing single crystal; the method involving melting feed rod material 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.

Abstract: Single crystals of semiconductor material are produced by an FZ method, wherein a molten zone is created between a feed rod and a growing single crystal; the method involving melting feed rod material 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.

Abstract: A growing single crystal is supported in the region of a conical section of the single crystal via a supporting body during crystallization of the single crystal by the FZ method. The method comprises pressing the supporting body against the conical section of the growing single crystal at a temperature at which a first material of the supporting body becomes soft, and continuing pressing the supporting body against the conical section of the growing single crystal until the first material and a second material of the supporting body that remains hard at the cited temperature touch the conical section of the growing single crystal.

Abstract: A growing single crystal is supported in the region of a conical section of the single crystal via a supporting body during crystallization of the single crystal by the FZ method. The method comprises pressing the supporting body against the conical section of the growing single crystal at a temperature at which a first material of the supporting body becomes soft, and continuing pressing the supporting body against the conical section of the growing single crystal until the first material and a second material of the supporting body that remains hard at the cited temperature touch the conical section of the growing single crystal.

Abstract: A process for producing doped semiconductor wafers from silicon, which contain an electrically active dopant, such as boron, phosphorus, arsenic or antimony, optionally are additionally doped with germanium and have a defined thermal conductivity, involves producing a single crystal from silicon and processing further to form semiconductor wafers, the thermal conductivity being established by selecting a concentration of the electrically active dopant and optionally a concentration of germanium. Semiconductor wafers produced from silicon by the process have specific properties with regard to thermal conductivity and resistivity.

Abstract: A process for producing doped semiconductor wafers from silicon, which contain an electrically active dopant, such as boron, phosphorus, arsenic or antimony, optionally are additionally doped with germanium and have a defined thermal conductivity, involves producing a single crystal from silicon and processing further to form semiconductor wafers, the thermal conductivity being established by selecting a concentration of the electrically active dopant and optionally a concentration of germanium. Semiconductor wafers produced from silicon by the process have specific properties with regard to thermal conductivity and resistivity.