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: 20110107960
    Abstract: Silicon single crystals are grown by a method of remelting silicon granules, by crystallizing a conically extended section of the single crystal with the aid of an induction heating coil arranged below a rotating plate composed of silicon; feeding inductively melted silicon through a conical tube in the plate, the tube enclosing a central opening of the plate and extending below the plate, to a melt situated on the conically extended section of the single crystal in contact with a tube end of the conical tube, wherein by means of the induction heating coil below the plate, sufficient energy is provided to ensure that the external diameter of the tube end is not smaller than 15 mm as long as the conically extended section of the single crystal has a diameter of 15 to 30 mm.
    Type: Application
    Filed: October 28, 2010
    Publication date: May 12, 2011
    Applicant: SILTRONIC AG
    Inventors: Wilfried von Ammon, Ludwig Altmannshofer, Martin Wasner
  • Publication number: 20110095018
    Abstract: A device for producing a silicon single crystal by remelting granules has a rotating plate of silicon having a central opening and having a silicon tubular extension which encloses the opening and extends below the plate; a first induction heating coil above the plate for melting granules; and a second induction heating coil below the plate for crystallizing the molten granules, wherein the second induction heating coil has, on its side lying opposite the silicon plate, a lower layer composed of a magnetically permeable material and an upper layer in which there is at least one cooling channel for conducting a coolant.
    Type: Application
    Filed: October 25, 2010
    Publication date: April 28, 2011
    Applicant: SILTRONIC AG
    Inventors: Wilfried von Ammon, Ludwig Altmannshofer, Andris Muiznieks
  • Publication number: 20110084366
    Abstract: The epitaxial layer defects generated from voids of a silicon substrate wafer containing added hydrogen are suppressed by a method for producing an epitaxial wafer by: growing a silicon crystal by the Czochralski method comprising adding hydrogen and nitrogen to a silicon melt and growing from the silicon melt a silicon crystal having a nitrogen concentration of from 3×1013 cm?3 to 3×1014 cm?3, preparing a silicon substrate by machining the silicon crystal, and forming an epitaxial layer at the surface of the silicon substrate.
    Type: Application
    Filed: October 1, 2010
    Publication date: April 14, 2011
    Applicant: SILTRONIC AG
    Inventors: Katsuhiko Nakai, Timo Mueller, Atsushi Ikari, Wilfried von Ammon, Martin Weber
  • Patent number: 7868325
    Abstract: Semiconductor wafer of monocrystalline silicon contain fluorine, the fluorine concentration being 1·1010 to 1·1016 atoms/cm3, and is free of agglomerated intrinsic point defects whose diameter is greater than or equal to a critical diameter. The semiconductor wafers are produced by providing a melt of silicon which is doped with fluorine, and crystallizing the melt to form a single crystal which contains fluorine within the range of 1·1010 to 1·1016 atoms/cm3, at a growth rate at which agglomerated intrinsic point defects having a critical diameter or larger would arise if fluorine were not present or present in too small an amount, and separating semiconductor wafers from the single crystal.
    Type: Grant
    Filed: February 18, 2009
    Date of Patent: January 11, 2011
    Assignee: Siltronic AG
    Inventor: Wilfried von Ammon
  • Patent number: 7828893
    Abstract: A silicon wafer having no epitaxially deposited layer or layer produced by joining to the silicon wafer, with a nitrogen concentration of 1·1013-8·1014 atoms/cm3, an oxygen concentration of 5.2·1017-7.5·1017 atoms/cm3, a central thickness BMD density of 3·108-2·1010 cm?3, a cumulative length of linear slippages ?3 cm and a cumulative area of areal slippage regions ?7 cm2, the front surface having <45 nitrogen-induced defects of >0.13 ?m LSE in the DNN channel, a layer at least 5 ?m thick, in which ?1·104 COPs/cm3 with a size of ?0.09 ?m occur, and a BMD-free layer ?5 ?m thick. Such wafers may be produced by heat treating the silicon wafer, resting on a substrate holder, a specific substrate holder used depending on the wafer doping. For each holder, maximum heating rates are selected to avoid formation of slippages.
    Type: Grant
    Filed: March 22, 2006
    Date of Patent: November 9, 2010
    Assignee: Siltronic AG
    Inventors: Timo Mueller, Wilfried von Ammon, Erich Daub, Peter Krottenthaler, Klaus Messmann, Friedrich Passek, Reinhold Wahlich, Arnold Kuehhorn, Johannes Studener
  • Patent number: 7771530
    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: Grant
    Filed: January 17, 2002
    Date of Patent: August 10, 2010
    Assignee: Siltronic AG
    Inventors: Janis Virbulis, Wilfried Von Ammon, Erich Tomzig, Yuri Gelfgat, Lenoid Gorbunov
  • Publication number: 20100158783
    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: December 17, 2009
    Publication date: June 24, 2010
    Applicant: Siltronic AG
    Inventor: Wilfried von Ammon
  • Patent number: 7708830
    Abstract: A method for the production of a silicon single crystal by pulling the single crystal, according to the Czochralski method, from a melt which is held in a rotating crucible, the single crystal growing at a growth front, heat being deliberately supplied to the center of the growth front by a heat flux directed at the growth front. The method produces a silicon single crystal with an oxygen content of from 4*1017 cm?3 to 7.2*1017 cm?3 and a radial concentration change for boron or phosphorus of less than 5%, which has no agglomerated self-point defects. Semiconductor wafers are separated from the single crystal. These semiconductor wafers have may have agglomerated vacancy defects (COPs) as the only self-point defect type or may have certain other defect distributions.
    Type: Grant
    Filed: August 31, 2006
    Date of Patent: May 4, 2010
    Assignee: Siltronic AG
    Inventors: Wilfried Von Ammon, Janis Virbulis, Martin Weber, Thomas Wetzel, Herbert Schmidt
  • Publication number: 20100037815
    Abstract: A single crystal of semiconductor material is produced by a method of melting semiconductor material granules by means of a first induction heating coil on a dish with a run-off tube consisting of the semiconductor material, forming a melt of molten granules which extends from the run-off tube in the form of a melt neck and a melt waist to a phase boundary, delivering heat to the melt by means of a second induction heating coil which has an opening through which the melt neck passes, crystallizing the melt at the phase boundary, and delivering a cooling gas to the run-off tube and to the melt neck in order to control the axial position of an interface between the run-off tube and the melt neck.
    Type: Application
    Filed: August 11, 2009
    Publication date: February 18, 2010
    Applicant: Siltronic AG
    Inventors: Wilfried von Ammon, Ludwig Altmannshofer, Helge Riemann, Joerg Fischer
  • Patent number: 7655089
    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: Grant
    Filed: September 30, 2008
    Date of Patent: February 2, 2010
    Assignee: Siltronic AG
    Inventor: Wilfried von Ammon
  • Publication number: 20090224366
    Abstract: Semiconductor wafer of monocrystalline silicon contain fluorine, the fluorine concentration being 1·1010 to 1·1016 atoms/cm3, and is free of agglomerated intrinsic point defects whose diameter is greater than or equal to a critical diameter. The semiconductor wafers are produced by providing a melt of silicon which is doped with fluorine, and crystallizing the melt to form a single crystal which contains fluorine within the range of 1·1010 to 1·1016 atoms/cm3, at a growth rate at which agglomerated intrinsic point defects having a critical diameter or larger would arise if fluorine were not present or present in too small an amount, and separating semiconductor wafers from the single crystal.
    Type: Application
    Filed: February 18, 2009
    Publication date: September 10, 2009
    Applicant: Siltronic AG
    Inventor: Wilfried von Ammon
  • Publication number: 20090223949
    Abstract: An induction heating coil melts granules composed of semiconductor material on a plate with an outlet tube. The induction heating coil has a coil body provided with current-guiding slots, the coil body having an upper side and a lower side and having a passage opening for granules in a region of the coil body that lies outside the center of the coil, and current-carrying segments which project from the center of the lower side of the coil body and which are electrically conductively connected by a web at a lower end.
    Type: Application
    Filed: February 26, 2009
    Publication date: September 10, 2009
    Applicant: SILTRONIC AG
    Inventors: Ludwig Altmannshofer, Joerg Fischer, Helge Riemann, Wilfried von Ammon
  • Patent number: 7537657
    Abstract: A process for producing a single-crystal silicon wafer, comprises the following steps: producing a layer on the front surface of the silicon wafer by epitaxial deposition or production of a layer whose electrical resistance differs from the electrical resistance of the remainder of the silicon wafer on the front surface of the silicon wafer, or production of an external getter layer on the back surface of the silicon wafer, and heat treating the silicon wafer at a temperature which is selected to be such that an inequality (1) [ Oi ] < [ Oi ] eq ? ( T ) ? exp ? 2 ? ? SiO ? ? 2 ? ? rkT is satisfied, where [Oi] is an oxygen concentration in the silicon wafer, [Oi]eq(T) is a limit solubility of oxygen in silicon at a temperature T, ?SiO2 is the surface energy of silicon dioxide, ? is a volume of a precipitated oxygen atom, r is a mean COP and k the Boltzmann constant, with the silicon wafer, during the heat treatment, at least part of the time being exposed to an oxygen-con
    Type: Grant
    Filed: June 29, 2006
    Date of Patent: May 26, 2009
    Assignee: Siltronic AG
    Inventors: Christoph Seuring, Robert Hoelzl, Reinhold Wahlich, Wilfried Von Ammon
  • Publication number: 20090084669
    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: September 30, 2008
    Publication date: April 2, 2009
    Applicant: Siltronic AG
    Inventor: Wilfried Von Ammon
  • Patent number: 7470323
    Abstract: The Czochralski method is used for producing p?-doped and epitaxially coated semiconductor wafers from silicon, wherein a silicon single crystal is pulled, and during the pulling is doped with boron, hydrogen and nitrogen, and the single crystal thus obtained is processed to form p?-doped semiconductor wafers which are epitaxially coated.
    Type: Grant
    Filed: October 11, 2007
    Date of Patent: December 30, 2008
    Assignee: Siltronic AG
    Inventors: Wilfried von Ammon, Katsuhiko Nakai, Martin Weber, Herbert Schmidt, Atsushi Ikari
  • Publication number: 20080268613
    Abstract: Hetero-semiconductor structures possessing an SOI structure containing a silicon-germanium mixed crystal are produced at a low cost and high productivity. The semiconductor substrates comprise a first layer formed of silicon having germanium added thereto, a second layer formed of an oxide and adjoined to the first layer, and a third layer derived from the same source as the first layer, but having an enriched content of germanium as a result of thermal oxidation and thinning of the third layer.
    Type: Application
    Filed: May 14, 2008
    Publication date: October 30, 2008
    Applicant: Siltronic AG
    Inventors: Josef Brunner, Hiroyuki Deai, Atsushi Ikari, Martin Grassl, Atsuki Matsumura, Wilfried von Ammon
  • Publication number: 20080210155
    Abstract: A silicon single crystal which has been produced using the Czochralski method has a <113> orientation.
    Type: Application
    Filed: February 28, 2008
    Publication date: September 4, 2008
    Applicant: SILTRONIC AG
    Inventors: Dirk Dantz, Wilfried Von Ammon, Dirk Zemke, Franz Segieth
  • Patent number: 7417297
    Abstract: SOI wafers are manufactured to have very thin device layers of high surface quality. The layer is ?20 nm in thickness, has an HF density of ?0.1/cm2, and a surface roughness of 0.2 nm RMS.
    Type: Grant
    Filed: March 20, 2006
    Date of Patent: August 26, 2008
    Assignee: Siltronic AG
    Inventors: Brian Murphy, Reinhold Wahlich, Rüdiger Schmolke, Wilfried Von Ammon, James Moreland
  • Publication number: 20080187736
    Abstract: Semiconductor wafers of silicon are produced by pulling a single crystal growing on a phase boundary from a melt contained in a crucible and cutting of semiconductor wafers therefrom, wherein during pulling of the single crystal, heat is delivered to a center of the phase boundary and a radial profile of a ratio V/G from the center to an edge of the phase boundary is controlled, G being the temperature gradient perpendicular to the phase boundary and V being the pull rate. The radial profile of the ratio V/G is controlled so that the effect of thermomechanical stress in the single crystal adjoining the phase boundary, is compensated with respect to creation of intrinsic point defects. The invention also relates to defect-free semiconductor wafers of silicon, which can be produced economically by this method.
    Type: Application
    Filed: January 29, 2008
    Publication date: August 7, 2008
    Applicant: Siltronic AG
    Inventors: Andreas Sattler, Wilfried von Ammon, Martin Weber, Walter Haeckl, Herbert Schmidt
  • Publication number: 20080153261
    Abstract: Semiconductor wafers of silicon are produced by pulling a single crystal from a melt contained in a crucible and slicing semiconductor wafers from the pulled single crystal, heat being delivered to a center of the growing single crystal at the boundary with the melt during the pulling of the single crystal, a CUSP magnetic field applied such that a neutral surface of the CUSP magnetic field intersects a pulling axis of the single crystal at a distance of at least 50 mm from a surface of the melt. An apparatus suitable therefore contains a CUSP field positioned such that a neutral field intersects the axis of the crystal in the crucible 50 mm or more from the melt surface.
    Type: Application
    Filed: December 19, 2007
    Publication date: June 26, 2008
    Applicant: Siltronic AG
    Inventors: Martin Weber, Herbert Schmidt, Wilfried von Ammon