Patents by Inventor Ludwig Altmannshofer
Ludwig Altmannshofer 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).
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Patent number: 11788201Abstract: 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.Type: GrantFiled: June 4, 2019Date of Patent: October 17, 2023Assignee: Siltronic AGInventors: Ludwig Altmannshofer, Goetz Meisterernst, Gundars Ratnieks, Simon Zitzelsberger
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Publication number: 20210222319Abstract: 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.Type: ApplicationFiled: June 4, 2019Publication date: July 22, 2021Applicant: SILTRONIC AGInventors: Ludwig ALTMANNSHOFER, Goetz MEISTERERNST, Gundars RATNIEKS, Simon ZITZELSBERGER
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Patent number: 9932691Abstract: A single crystal is grown in a float zone which is inductively heated and the crystallizing single crystal is rotated in a direction of rotation which is periodically reversed at intervals in accordance with an alternating plan, wherein a dwell time during which the single crystal is in a state of rest because of the reversal of the direction of rotation is limited to no more than 60 ms.Type: GrantFiled: November 19, 2015Date of Patent: April 3, 2018Assignee: SILTRONIC AGInventors: Georg Raming, Ludwig Altmannshofer, Gundars Ratnieks, Martin Moeller, Frank Muemmler
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Patent number: 9932690Abstract: A device for producing a single crystal by crystallizing the single crystal in a melt zone, comprising a housing, an inductor for generating heat in the melt zone, a reheater which surrounds and applies thermal radiation to the crystallizing single crystal, and a separating bottom which delimits downward an intermediate space between the reheater and a wall of the housing at a lower end of the reheater.Type: GrantFiled: July 1, 2013Date of Patent: April 3, 2018Assignee: SILTRONIC AGInventors: Georg Raming, Ludwig Altmannshofer
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Patent number: 9422634Abstract: Single crystals are produced by means of the floating zone method, wherein the single crystal crystallizes below a melt zone at a crystallization boundary, and the emission of crystallization heat is impeded by a reflector surrounding the single crystal, wherein the single crystal is heated in the region of an outer edge of the crystallization boundary by means of a heating device in a first zone, wherein a distance ? between an outer triple point Ta at the outer edge of the crystallization boundary and a center Z of the crystallization boundary is influenced. An apparatus for producing the single crystal provides a heat source below the melting induction coil and above the reflector.Type: GrantFiled: December 5, 2012Date of Patent: August 23, 2016Assignee: SILTRONIC AGInventors: Georg Raming, Ludwig Altmannshofer, Gundars Ratnieks, Johann Landrichinger, Josef Lobmeyer, Alfred Holzinger
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Publication number: 20160177469Abstract: A single crystal is grown in a float zone which is inductively heated and the crystallizing single crystal is rotated in a direction of rotation which is periodically reversed at intervals in accordance with an alternating plan, wherein a dwell time during which the single crystal is in a state of rest because of the reversal of the direction of rotation is limited to no more than 60 ms.Type: ApplicationFiled: November 19, 2015Publication date: June 23, 2016Inventors: Georg RAMING, Ludwig ALTMANNSHOFER, Gundars RATNIEKS, Martin MOELLER, Frank MUEMMLER
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Publication number: 20150203987Abstract: A device for producing a single crystal by crystallizing the single crystal in a melt zone, comprising a housing, an inductor for generating heat in the melt zone, a reheater which surrounds and applies thermal radiation to the crystallizing single crystal, and a separating bottom which delimits downward an intermediate space between the reheater and a wall of the housing at a lower end of the reheater.Type: ApplicationFiled: July 1, 2013Publication date: July 23, 2015Inventors: Georg Raming, Ludwig Altmannshofer
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Patent number: 9084296Abstract: 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: GrantFiled: February 26, 2009Date of Patent: July 14, 2015Assignee: Siltronic AGInventors: Ludwig Altmannshofer, Joerg Fischer, Helge Riemann, Wilfried von Ammon
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Patent number: 8834627Abstract: 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: GrantFiled: October 28, 2010Date of Patent: September 16, 2014Assignee: Siltronic AGInventors: Wilfried von Ammon, Ludwig Altmannshofer, Martin Wasner
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Patent number: 8580033Abstract: 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: GrantFiled: March 13, 2013Date of Patent: November 12, 2013Assignee: Siltronic AGInventors: Wilfried von Ammon, Ludwig Altmannshofer, Helge Riemann, Joerg Fischer
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Patent number: 8475592Abstract: 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: GrantFiled: August 11, 2009Date of Patent: July 2, 2013Assignee: Siltronic AGInventors: Wilfried von Ammon, Ludwig Altmannshofer, Helge Riemann, Joerg Fischer
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Patent number: 8454746Abstract: Silicon single crystals are prepared from molten granules, by producing a first volume of molten silicon between a growing single crystal and the lower end of a silicon conical tube which is closed at its lower end, and encloses a central opening of a rotating silicon plate below which the tube extends, by means of a first induction heating coil arranged below the plate; producing a second volume of molten silicon by a second induction heating coil arranged above the plate; melting the lower end of the tube to form a passage for the second volume of molten silicon, the passage produced at a point in time when the second volume is not yet present or is less than double the volume of the first volume; and crystallizing monocrystalline silicon on the growing single crystal with consumption of molten silicon from the first and the second volume.Type: GrantFiled: January 18, 2011Date of Patent: June 4, 2013Assignee: Siltronic AGInventors: Wilfried von Ammon, Ludwig Altmannshofer
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Publication number: 20110185963Abstract: Silicon single crystals are prepared from molten granules, by producing a first volume of molten silicon between a growing single crystal and the lower end of a silicon conical tube which is closed at its lower end, and encloses a central opening of a rotating silicon plate below which the tube extends, by means of a first induction heating coil arranged below the plate; producing a second volume of molten silicon by a second induction heating coil arranged above the plate; melting the lower end of the tube to form a passage for the second volume of molten silicon, the passage produced at a point in time when the second volume is not yet present or is less than double the volume of the first volume; and crystallizing monocrystalline silicon on the growing single crystal with consumption of molten silicon from the first and the second volume.Type: ApplicationFiled: January 18, 2011Publication date: August 4, 2011Applicant: SILTRONIC AGInventors: Wilfried Von Ammon, Ludwig Altmannshofer
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Publication number: 20110107960Abstract: 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: ApplicationFiled: October 28, 2010Publication date: May 12, 2011Applicant: SILTRONIC AGInventors: Wilfried von Ammon, Ludwig Altmannshofer, Martin Wasner
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Publication number: 20110095018Abstract: 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: ApplicationFiled: October 25, 2010Publication date: April 28, 2011Applicant: SILTRONIC AGInventors: Wilfried von Ammon, Ludwig Altmannshofer, Andris Muiznieks
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Publication number: 20100037815Abstract: 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: ApplicationFiled: August 11, 2009Publication date: February 18, 2010Applicant: Siltronic AGInventors: Wilfried von Ammon, Ludwig Altmannshofer, Helge Riemann, Joerg Fischer
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Publication number: 20090223949Abstract: 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: ApplicationFiled: February 26, 2009Publication date: September 10, 2009Applicant: SILTRONIC AGInventors: Ludwig Altmannshofer, Joerg Fischer, Helge Riemann, Wilfried von Ammon
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Patent number: 7011704Abstract: A method for the production of a single crystal has the single crystal crystallizing from a melt and being subjected to a rotation with an alternating rotation direction. The single crystal is periodically rotated through a sequence of rotation angles, and the rotation direction is changed after each rotation through a rotation angle of the sequence, with a change of the rotation direction defining an inversion point on the circumference of the single crystal. There is at least one recurring pattern of inversion points created, in which the inversion points lie distributed on straight lines that are aligned parallel with the z-axis and are spaced apart uniformly from one another.Type: GrantFiled: July 31, 2002Date of Patent: March 14, 2006Assignee: Wacker Siltronic Gesellschaft Fur Halbleitermaterialien AGInventor: Ludwig Altmannshofer
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Patent number: 6840998Abstract: A silicon single crystal is produced by crucible-free float zone pulling, has a diameter of at least 200 mm over a length of at least 200 mm and is free of dislocations in the region of this length. A silicon wafer is separated from the silicon single crystal by a process for producing the silicon single crystal. The silicon single crystal is produced by crucible-free float zone pulling in a receptacle, in which an atmosphere of inert gas and nitrogen exerts a pressure of 1.5-2.2 bar, the atmosphere being continuously exchanged, with the volume of the receptacle being exchanged at least twice per hour. A flat coil with an external diameter of at least 220 mm is inserted in order to melt a stock ingot. The single crystal is pulled at a rate in a range from 1.4-2.2 mm/min and is periodically rotated through a sequence of rotation angles.Type: GrantFiled: July 23, 2002Date of Patent: January 11, 2005Assignee: Siltronic AGInventors: Ludwig Altmannshofer, Manfred Grundner, Janis Virbulis
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Publication number: 20030024469Abstract: A silicon single crystal is produced by crucible-free float zone pulling, has a diameter of at least 200 mm over a length of at least 200 mm and is free of dislocations in the region of this length. A silicon wafer is separated from the silicon single crystal by a process for producing the silicon single crystal. The silicon single crystal is produced by crucible-free float zone pulling in a receptacle, in which an atmosphere of inert gas and nitrogen exerts a pressure of 1.5-2.2 bar, the atmosphere being continuously exchanged, with the volume of the receptacle being exchanged at least twice per hour. A flat coil with an external diameter of at least 220 mm is inserted in order to melt a stock ingot. The single crystal is pulled at a rate in a range from 1.4-2.2 mm/min and is periodically rotated through a sequence of rotation angles.Type: ApplicationFiled: July 23, 2002Publication date: February 6, 2003Applicant: Wacker Siltronic Gesellschaft Fur Halbleitermaterialien AGInventors: Ludwig Altmannshofer, Manfred Grundner, Janis Virbulis