Patents by Inventor Wilfried von Ammon

Wilfried von Ammon 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).

  • Publication number: 20030192470
    Abstract: A doped semiconductor wafer of float zone-pulled semiconductor material contains a dopant added to a molten material and has a radial macroscopic resistance distribution of less than 12% and striations of −10% to +10%. There is also a process for producing a doped semiconductor wafer by float zone pulling of a single crystal and dividing up the single crystal, in which process, during the float zone pulling, a molten material which is produced using an induction coil is doped with a dopant. It is exposed to at least one rotating magnetic field and is solidified. The single crystal which is formed during the solidification of the molten material is rotated. The single crystal and the magnetic field are rotated with opposite directions of rotation and the magnetic field has a frequency of 400 to 700 Hz.
    Type: Application
    Filed: April 10, 2003
    Publication date: October 16, 2003
    Applicant: Wacker Siltronic AG
    Inventors: Rolf Knobel, Wilfried Von Ammon, Janis Virbulis, Manfred Grundner
  • Publication number: 20030148634
    Abstract: A process for the heat treatment of a silicon wafer, during which the silicon wafer is at least temporarily exposed to an oxygen-containing atmosphere, the heat treatment taking place at a temperature which is selected in such a way that the inequality 1 [ Oi ] < [ Oi ] eq ⁢ ( T ) ⁢ exp ⁢ ( 2 ⁢ σ SiO 2 ⁢ Ω rkT )
    Type: Application
    Filed: February 4, 2003
    Publication date: August 7, 2003
    Applicant: Wacker Siltronic AG.
    Inventors: Robert Holzl, Christoph Seuring, Reinhold Wahlich, Wilfried Von Ammon
  • Publication number: 20030145781
    Abstract: A process for producing a single crystal of semiconductor material, in which fractions of a melt, are kept in liquid form by a pulling coil, solidify on a seed crystal to form the growing single crystal, and granules are melted in order to maintain the growth of the single crystal. The melting granules are passed to the melt after a delay. There is also an apparatus which is suitable for carrying out the process and has a device which delays mixing of the molten granules and of the melt.
    Type: Application
    Filed: January 24, 2003
    Publication date: August 7, 2003
    Applicant: WACKER SILTRONIC AG
    Inventor: Wilfried Von Ammon
  • Publication number: 20030145780
    Abstract: A silicon single crystal which has been produced using the Czochralski method has a <113 > orientation.
    Type: Application
    Filed: January 27, 2003
    Publication date: August 7, 2003
    Applicant: WACKER SILTRONIC AG
    Inventors: Dirk Dantz, Wilfried Von Ammon, Dirk Zemke, Franz Segieth
  • Publication number: 20020092461
    Abstract: A process for producing a silicon single crystal is by pulling the single crystal from a silicon melt which is contained in a crucible with a diameter of at least 450 mm, above which a heat shield is arranged. The single crystal being pulled has a diameter of at least 200 mm. The silicon melt is exposed to the influence of a traveling magnetic field which exerts a substantially vertically oriented force on the melt in the region of the crucible wall. There is also an apparatus which is suitable for carrying out the process.
    Type: Application
    Filed: January 17, 2002
    Publication date: July 18, 2002
    Inventors: Janis Virbulis, Wilfried Von Ammon, Erich Tomzig, Yuri Gelfgat, Leonid Gorbunov
  • Patent number: 6395653
    Abstract: A semiconductor wafer has a front side 1, a back side 2, a top layer 3, a bottom layer 4, an upper inner layer 5 lying beneath the top layer 3, an lower inner layer 6 lying above the bottom layer 4, a central region 7 between the layers 5 and 6, and an uneven distribution of crystal lattice defects. The crystal lattice defects are substitutionally or interstitially included nitrogen or vacancies.
    Type: Grant
    Filed: May 22, 2000
    Date of Patent: May 28, 2002
    Assignee: Wacker Siltronic Gesellschaft für Halbleitermaterialien AG
    Inventors: Gunther Obermeier, Alfred Buchner, Theresia Bauer, Jürgen Hage, Rasso Ostermeir, Wilfried Von Ammon
  • Patent number: 6350314
    Abstract: A process for producing nitrogen-doped semiconductor wafers has the nitrogen being derived from a dopant gas which contains NH3. The process includes pulling a single crystal from a melt of molten semiconductor material, feeding the dopant gas to the semiconductor material, and cutting the nitrogen-doped semiconductor wafers off the pulled single crystal. The dopant gas is fed to the semiconductor material at most until pulling begins for that part of the single crystal from which the semiconductor wafers are cut.
    Type: Grant
    Filed: August 31, 2000
    Date of Patent: February 26, 2002
    Assignee: Wacker Siltronic Gesellschaft für Halbleitermaterialien AG
    Inventors: Wilfried Von Ammon, Herbert Weidner, Dirk Zemke, Christoph Frey
  • Publication number: 20010023941
    Abstract: A semiconductor wafer made from silicon which is doped with hydrogen. The hydrogen concentration is less than 5*1016 atcm−3 and greater than 1*1012 atcm−3. A method for producing a semiconductor wafer from silicon includes separating the semiconductor wafer from a silicon single crystal, with the single silicon crystal being pulled from a melt, in the presence of hydrogen, using the Czochralski method. The hydrogen partial pressure during the pulling of the single silicon crystal is less than 3 mbar.
    Type: Application
    Filed: March 20, 2001
    Publication date: September 27, 2001
    Applicant: WACKER SILTRONIC GESELLSCHAFT FUR HALBLEITERMATERIALIEN AG
    Inventors: Wilfried Von Ammon, Rudiger Schmolke, Erich Daub, Christoph Frey
  • Patent number: 6267815
    Abstract: A method for pulling a single crystal has a monocrystalline seed crystal being brought into contact with molten material and an interface being formed between solid and molten material, and molten material being caused to solidify with the formation of a thin-necked crystal and a cylindrical single crystal. The method is one wherein, during the pulling of the thin-necked crystal, it is ensured that the ratio V/G(r) is above a constant Ccrit having the value 1.3*10−3 cm2/Kmin, with V being the pulling rate, with G(r) being the axial temperature gradient at the interface and r being the radial distance from the center of the thin-necked crystal.
    Type: Grant
    Filed: October 5, 1999
    Date of Patent: July 31, 2001
    Assignee: Wacker Siltronic Gesellschaft für Halbleitermaterialien AG
    Inventors: Andreas Ehlert, Erich Dornberger, Wilfried Von Ammon
  • Patent number: 6238477
    Abstract: A process and device for the production of a single crystal of semiconductor material is by pulling the single crystal from a melt, which is contained in a crucible and is heated by a side heater surrounding the crucible. The melt is additionally heated, in an annular region around the single crystal, by an annular heating device which surrounds the single crystal and is positioned above the melt.
    Type: Grant
    Filed: March 7, 2000
    Date of Patent: May 29, 2001
    Assignee: Wacker Siltronic Gesellschaft für Halbleitermaterialien AG
    Inventors: Wilfried von Ammon, Erich Tomzig, Janis Virbulis
  • Patent number: 6228164
    Abstract: A process for producing a silicon single crystal has the crystal being pulled using the Czochralski method while being doped with oxygen and nitrogen. The single crystal is doped with oxygen at a concentration of less than 6.5*1017 atoms cm−3 and with nitrogen at a concentration of more than 5*1013 atoms cm−3 while the single crystal is being pulled. Another process is for producing a single crystal from a silicon melt, in which the single crystal is doped with nitrogen and the single crystal is pulled at a rate V, an axial temperature gradient G(r) being set up at the interface of the single crystal and the melt, in which the ratio V/G(r) in the radial direction is at least partially less than 1.3*10−3cm2min−1 K−1.
    Type: Grant
    Filed: May 25, 1999
    Date of Patent: May 8, 2001
    Assignee: Wacker Siltronic Gesellschaft für Halbleitermaterialien AG
    Inventors: Wilfried von Ammon, Rüdiger Schmolke, Dieter Gräf, Ulrich Lambert
  • Patent number: 6171395
    Abstract: The invention relates to a process for melting semiconductor material in a crucible which is located in a container, and is enclosed by a fixed heating device. The invention also relates to a heating device which is suitable for carrying out the process. The process is one wherein a heater of a displaceable heating device is lowered from a lock chamber above the container through an open shut-off valve into the container in the direction of the semiconductor material, and the semiconductor material is melted using the fixed heating device and the lowered heater. The heater is then raised back out of the container into the lock chamber after the semiconductor material has been melted. A door is provided in the lock chamber to allow the displaceable heater to be removed after the semiconductor material has been melted.
    Type: Grant
    Filed: December 1, 1998
    Date of Patent: January 9, 2001
    Assignee: Wacker Siltronic Gesellschaft f{umlaut over (u)}r Halbleitermaterialien AG
    Inventors: Wilfried von Ammon, Erich Tomzig, Paul Fuchs
  • Patent number: 6153008
    Abstract: Device for pulling a silicon single crystal 1 includes an element 5 which annularly surrounds the single crystal growing at a crystallization boundary; and the element has a face 6 directed at the single crystal. The element surrounds the single crystal substantially level with the crystallization boundary 2 and has the property of reflecting heat radiation radiated by the single crystal and the similar melt or of generating and radiating heat radiation back to the lower part of the crystal close to the crystallization boundary. There is also a method for pulling a silicon single crystal, in which the single crystal is thermally affected using the element surrounding it.
    Type: Grant
    Filed: March 20, 1998
    Date of Patent: November 28, 2000
    Assignee: Wacker Siltronic Gesellschaft fur Halbleitermaterialien AG
    Inventors: Wilfried Von Ammon, Hans Olkrug, Erich Dornberger, Franz Segieth
  • Patent number: 6132507
    Abstract: A process and device for the production of a single crystal of semiconductor material is by pulling the single crystal from a melt, which is contained in a crucible and is heated by a side heater surrounding the crucible. The melt is additionally heated, in an annular region around the single crystal, by an annular heating device which surrounds the single crystal and is positioned above the melt.
    Type: Grant
    Filed: December 4, 1998
    Date of Patent: October 17, 2000
    Assignee: Wacker Siltronic Gesellschaft fur Halbleitermaterialien AG
    Inventors: Wilfried von Ammon, Erich Tomzig, Janis Virbulis
  • Patent number: 6117230
    Abstract: A process for producing a silicon single crystal by the Czochralski method, utilizes a heater which is intended for heating a silicon-filled crucible and is arranged below the crucible. The process has energy delivered to the melt at least some of the time inductively using a coiled heater arranged under the crucible. The heater is in the form of a wound coil.
    Type: Grant
    Filed: November 25, 1997
    Date of Patent: September 12, 2000
    Assignee: Wacker Siltronic Gesellschaft fur Halbleitermaterialien AG
    Inventors: Wilfried Von Ammon, Erich Tomzig, Paul Fuchs, Yuri Gelfgat
  • Patent number: 6059874
    Abstract: A process for reducing the load on a seed crystal during the pulling of a single crystal uses a pulling device. An adhesive bond is made between a conical section at the start of the single crystal and a retaining body. The load on the seed crystal is reduced by creating a tensile stress between the retaining body and the pulling device.
    Type: Grant
    Filed: August 18, 1998
    Date of Patent: May 9, 2000
    Assignee: Wacker Siltronic Gesellschaft fur Halbleitermaterialien AG
    Inventor: Wilfried Von Ammon
  • Patent number: 6015460
    Abstract: A method and an apparatus for pulling a silicon monocrystal from a melt iudes the pulling of a conical portion in each case at the beginning and at the end of the monocrystal and the pulling of a cylindrical portion between the conical portions. In this method, the surface of the conical portion at the beginning of the monocrystal is shielded by a shielding means spaced apart from the monocrystal.
    Type: Grant
    Filed: March 13, 1998
    Date of Patent: January 18, 2000
    Assignee: Wacker Siltronic Gesellschaft fur Halbleitermaterialien AG
    Inventors: Erich Dornberger, Wilfried Von Ammon
  • Patent number: 6001170
    Abstract: A process for the growth of a single crystal from semiconductor material by the Czochralski method, in which the melt is subjected to the influence of a magnetic field during the crystal growth and the magnetic field is generated by superposing a static magnetic field and an alternating magnetic field. An apparatus for carrying out the process, has a magnetic means which comprises two coils which are arranged around a crucible, one coil generating a static magnetic field and the other coil generating an alternating magnetic field.
    Type: Grant
    Filed: August 9, 1996
    Date of Patent: December 14, 1999
    Assignee: Wacker Siltronik Gesellschaft fur Halbleitermaterialien AG
    Inventors: Erich Tomzig, Werner Zulehner, Wilfried Von Ammon, Yu M Gelfgat, Leonid Gorbunov
  • Patent number: 5951753
    Abstract: A method for producing a silicon monocrystal has a growing monocrystal kept for a specified dwell time in the specified temperature range of from 850.degree. C. to 1100.degree. C. This dwell time for the growing monocrystal in the chosen temperature range is either greater than 250 min or less than 80 min. A device and a method, in which the cooling rate of the growing monocrystal is to be influenced, has a heat shield which is subdivided into adjacent annular zones between a lower rim and an upper rim. These adjacent zones differ in regard to each's thermal conduction and transparency to heat radiation.
    Type: Grant
    Filed: May 9, 1997
    Date of Patent: September 14, 1999
    Assignee: Wacker Siltronic Gesellschaft fur Halbleitermaterialien AG
    Inventors: Erich Dornberger, Hans Olkrug, Wilfried Von Ammon, Dieter Graf
  • Patent number: 5935320
    Abstract: A process for producing silicon wafers with low defect density is one wherein a) a silicon single crystal having an oxygen doping concentration of at least 4*10.sup.17 /cm.sup.3 is produced by molten material being solidified to form a single crystal and is then cooled, and the holding time of the single crystal during cooling in the temperature range of from 850.degree. C. to 1100.degree. C. is less than 80 minutes; b) the single crystal is processed to form silicon wafers; and c) the silicon wafers are annealed at a temperature of at least 1000.degree. C. for at least one hour. Also, it is possible to prepare a silicon single crystal based upon having an oxygen doping concentration of at least 4*10.sup.17 /cm.sup.3 and a nitrogen doping concentration of at least 1*10.sup.14 /cm.sup.3 for (a) above.
    Type: Grant
    Filed: August 26, 1997
    Date of Patent: August 10, 1999
    Assignee: Wacker Siltronic Gesellschaft fur Halbleitermaterialien AG
    Inventors: Dieter Graef, Wilfried Von Ammon, Reinhold Wahlich, Peter Krottenthaler, Ulrich Lambert