Patents by Inventor Andreas Muhe

Andreas Muhe has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7662231
    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.
    Type: Grant
    Filed: March 11, 2005
    Date of Patent: February 16, 2010
    Assignee: Crystal Growing Systems GmbH
    Inventor: Andreas Mühe
  • Publication number: 20080000415
    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.
    Type: Application
    Filed: March 11, 2005
    Publication date: January 3, 2008
    Inventor: Andreas Muhe
  • Patent number: 7261773
    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.
    Type: Grant
    Filed: August 26, 2004
    Date of Patent: August 28, 2007
    Assignee: Crystal Growing Systems GmbH
    Inventors: Andreas Mühe, Burkhard Altekrüger, Axel Vonhoff
  • Patent number: 7261774
    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.
    Type: Grant
    Filed: August 27, 2003
    Date of Patent: August 28, 2007
    Assignee: Crystal Growing System GmbH
    Inventor: Andreas Mühe
  • Publication number: 20070151510
    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 (4) and doing so at a low cost. Therefore, jacket heaters (11, 12) are provided coaxially with the furnace core containing the crucible (6) and measurement devices for determining radial temperature differences in the space between the jacket heaters (11, 12) and the crucible (6), whereby the heat output of the jacket heaters (11, 12) 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.
    Type: Application
    Filed: March 20, 2007
    Publication date: July 5, 2007
    Inventor: Andreas Muhe
  • Patent number: 7179331
    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.
    Type: Grant
    Filed: August 19, 2004
    Date of Patent: February 20, 2007
    Assignee: Crystal Growing Systems GmbH
    Inventors: Andreas Mühe, Burkhard Altekrüger, Axel Vonhoff
  • Patent number: 7125452
    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.
    Type: Grant
    Filed: July 30, 2003
    Date of Patent: October 24, 2006
    Assignee: Crystal Growing Systems GmbH
    Inventor: Andreas Mühe
  • Publication number: 20050275144
    Abstract: The invention is based on the problem of 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 suggests the provision of means for distributing the granulate. Especially suitable means are inductors (6) arranged outside the melting crucible (3) that generate an alternating magnetic field in the melt. In this way, electrical currents are induced there that in turn cause the material flows. 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.
    Type: Application
    Filed: August 26, 2004
    Publication date: December 15, 2005
    Inventors: Andreas Muhe, Burkhard Altekruger, Axel Vonhoff
  • Publication number: 20050087125
    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.
    Type: Application
    Filed: August 19, 2004
    Publication date: April 28, 2005
    Inventors: Andreas Muhe, Burkhard Altekruger, Axel Vonhoff
  • Publication number: 20050076827
    Abstract: In 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) than 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. In the process the difference to the temperature of the respective control temperature indicators (11, 12, 13) is determined.
    Type: Application
    Filed: July 30, 2003
    Publication date: April 14, 2005
    Inventor: Andreas Muhe
  • Publication number: 20040079276
    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 (4) and doing so at a low cost.
    Type: Application
    Filed: August 27, 2003
    Publication date: April 29, 2004
    Inventor: Andreas Muhe