Abstract: 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.

Abstract: 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.

Abstract: A monocrystalline semiconductor wafers have an average roughness Ra of at most 0.8 nm at a limiting wavelength of 250 ?m, and an ESFQRavg of 8 nm or less given an edge exclusion of 1 mm. The wafers are advantageously produced by a method comprising the following steps in the indicated order: a) simultaneous double-side polishing of the semiconductor wafer, b) local material-removing processing of at least one part of at least one side of the semiconductor wafer using a fluid jet which contains suspended hard substance particles and which is directed onto a small region of the surface with the aid of a nozzle, wherein the nozzle is moved over that part of the surface which is to be treated in such a way that a predefined geometry parameter of the semiconductor wafer is improved, and c) polishing of the at least one surface of the semiconductor wafer.

Abstract: A monocrystalline semiconductor wafers have an average roughness Ra of at most 0.8 nm at a limiting wavelength of 250 ?m, and an ESFQRavg of 8 nm or less given an edge exclusion of 1 mm. The wafers are advantageously produced by a method comprising the following steps in the indicated order: simultaneous double-side polishing of the semiconductor wafer, b) local material-removing processing of at least one part of at least one side of the semiconductor wafer using a fluid jet which contains suspended hard substance particles and which is directed onto a small region of the surface with the aid of a nozzle, wherein the nozzle is moved over that part of the surface which is to be treated in such a way that a predefined geometry parameter of the semiconductor wafer is improved, and c) polishing of the at least one surface of the semiconductor wafer.

Abstract: A device for pulling a single crystal from a melt having a widened portion between an upper and a lower neck portion including a pulling device having a pulling device cable drum configured to wind a pulling cable, the pulling cable configured to pull the single crystal and a supporting device configured to relieve the upper neck portion of a weight of the single crystal.

Abstract: A device for pulling a single crystal from a melt having a widened portion between an upper and a lower neck portion including a pulling device having a pulling device cable drum configured to wind a pulling cable, the pulling cable configured to pull the single crystal and a supporting device configured to relieve the upper neck portion of a weight of the single crystal.

Abstract: The invention relates to the production of a cable rotating head, which is devoid of an abrasion ring, for a Czochralski-crystal drawing system which is used to drive a drawing cord in an azimuthal and vertical manner and the nucleus of a crystal is fixed therein. According to the invention, the cord rotating head comprises a cord winding mechanism which can be supported by a vertical hollow shaft, through which the drawing cord is suspended in the crystal drawing system, and the cord rotating head is rotationally mounted about the axis thereof and can be offset by a rotation motor, which is secured to the crystal drawing system, together with the cord winding mechanism and the drawing cord in a rotational movement, and said vertical hollow shaft is surrounded in a coaxial manner by a double toothed gear which is rotationally mounted opposite to the hollow shaft and can be driven by a drawing motor which is secured to the crystal drawing system.

Abstract: The invention relates to producing a melt that is as homogeneous as possible, to which fresh material in the form of granulate is continuously supplied. Since the granulate is cooler than the melt, heat sinks form that are especially pronounced when the granulate forms clumps in the melt. Therefore, the invention relates to a means for distributing the granulate. In one aspect, the means are inductors arranged outside the melting crucible that generate an alternating magnetic field in the melt. In this way, electrical currents are induced there that, in turn, cause the material flows. In one aspect, the inductors are arranged and controlled in such a way that a rapid distribution of the granulate is effected and thus its rapid melting. In this way, good homogeneity is achieved, especially in the center of the melt where the removal of the melted material also occurs.

Abstract: This invention is based on the problem of achieving the most planar possible phase boundary extending in the horizontal direction between the still molten material and the material that has already crystallized out in a vertical Bridgman crystal-growing furnace or vertical gradient freeze crystal-growing furnace for crystallizing out the semiconductor melt and doing so at a low cost. Therefore, jacket heaters are provided coaxially with the furnace core containing the crucible and measurement devices for determining radial temperature differences in the space between the jacket heaters and the crucible, whereby the heat output of the jacket heaters is adjusted so that the measured temperature differences become zero. Thus, at least in the planes in which the measurement devices are located, radial heat transport is prevented and a phase boundary that is not curved is implemented.

Abstract: The invention presented here relates to a crystal growing equipment. It is equipped in general with a resistance heater for heating a melt (13) as well as with field coils, which generate alternating magnetic field in a crucible, with which flows can be induced in the melt (13). The invention is so designed that the resistance heaters are also devised to function as the field coils, that is, they are built of a hollow cylindrical body (1), in which, by means of a surrounding slit (2) which winds around it, a spiral-shaped single layer current path is formed. This has the advantage that the current needed for the electrical heating in the equipment is also used for the generation of the magnetic field. Thus, neither separate field coils nor a separate current supply is necessary. Further, the resistance heater, which serves as the field coil arranged as a coil array, is high temperature resistant and surrounds the immediate hot core zone of the equipment and thus the region of the melt.

Abstract: A process for calibrating the temperature control unit of a vertical gradient freeze crystal growth oven, instead of the fused material a test body (3) is used in the oven (1) that does not melt at the oven temperature, that has a heat conductivity comparable to the fused material and a central bore (4). After turning on the resistance heaters (8, 9, 10) of the oven (1) the temperature at the level of the individual control temperature indicators (11, 12, 13) of the oven (1) is measured via a reference temperature indicator (5) that can be fully inserted into the bore (4) and subsequently the output of the respective resistance heaters (8, 9, 10) is set to a desired temperature value.