Patents by Inventor Dieter Gräf
Dieter Gräf 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: 8323403Abstract: An SOI wafer is constructed from a carrier wafer and a monocrystalline silicon layer having a thickness of less than 500 nm, an excess of interstitial silicon atoms prevailing in the entire volume of the silicon layer. The SOI wafers may be prepared by Czochralski silicon single crystal growth, the condition v/G<(v/G)crit=1.3×10?3 cm2/(K·min) being fulfilled at the crystallization front over the entire crystal cross section, with the result that an excess of interstitial silicon atoms prevails in the silicon single crystal produced; separation of at least one donor wafer from this silicon single crystal, bonding of the donor wafer to a carrier wafer, and reduction of the thickness of the donor wafer, with the result that a silicon layer having a thickness of less than 500 nm bonded to the carrier wafer remains.Type: GrantFiled: January 18, 2008Date of Patent: December 4, 2012Assignee: Siltronic AGInventors: Dieter Graef, Markus Blietz, Reinhold Wahlich, Alfred Miller, Dirk Zemke
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Patent number: 7394129Abstract: An SOI wafer is constructed from a carrier wafer and a monocrystalline silicon layer having a thickness of less than 500 nm, an excess of interstitial silicon atoms prevailing in the entire volume of the silicon layer. The SOI wafers may be prepared by Czochralski silicon single crystal growth, the condition v/G<(v/G)crit=1.3×10?3 cm2/(K·min) being fulfilled at the crystallization front over the entire crystal cross section, with the result that an excess of interstitial silicon atoms prevails in the silicon single crystal produced; separation of at least one donor wafer from this silicon single crystal, bonding of the donor wafer to a carrier wafer, and reduction of the thickness of the donor wafer, with the result that a silicon layer having a thickness of less than 500 nm bonded to the carrier wafer remains.Type: GrantFiled: April 13, 2005Date of Patent: July 1, 2008Assignee: Siltronic AGInventors: Dieter Gräf, Markus Blietz, Reinhold Wahlich, Alfred Miller, Dirk Zemke
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Publication number: 20080153259Abstract: An SOI wafer is constructed from a carrier wafer and a monocrystalline silicon layer having a thickness of less than 500 nm, an excess of interstitial silicon atoms prevailing in the entire volume of the silicon layer. The SOI wafers may be prepared by Czochralski silicon single crystal growth, the condition v/G<(v/G)crit=1.3×10?3 cm2/(K·min) being fulfilled at the crystallization front over the entire crystal cross section, with the result that an excess of interstitial silicon atoms prevails in the silicon single crystal produced; separation of at least one donor wafer from this silicon single crystal, bonding of the donor wafer to a carrier wafer, and reduction of the thickness of the donor wafer, with the result that a silicon layer having a thickness of less than 500 nm bonded to the carrier wafer remains.Type: ApplicationFiled: January 18, 2008Publication date: June 26, 2008Applicant: SILTRONIC AGInventors: Dieter Graef, Markus Blietz, Reinhold Wahlich, Alfred Miller, Dirk Zemke
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Patent number: 6630024Abstract: A method for the production of a semiconductor wafer having a front and a back and an epitaxial layer of semiconductor material deposited on the front, includes the following process steps: (a) preparing a substrate wafer having a polished front and a specific thickness; (b) pretreating the front of the substrate wafer in the presence of HCl gas and a silane source at a temperature of from 950 to 1250 degrees Celsius in an epitaxy reactor, the thickness of the substrate wafer remaining substantially unchanged; and (c) depositing the epitaxial layer on the front of the pretreated substrate wafer.Type: GrantFiled: May 24, 2001Date of Patent: October 7, 2003Assignee: Wacker Siltronic Gesellschaft für Halbleitermaterialien AGInventors: Rüdiger Schmolke, Reinhard Schauer, Günther Obermeier, Dieter Gräf, Peter Storck, Klaus Messmann, Wolfgang Siebert
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Patent number: 6333785Abstract: The invention relates to a reproducible standard for calibrating and checking the bright-field channel of a surface inspection device used for examining the flat surface of a sample and to a method for producing said standard whereby a microstructure is produced on a surface of a substrate provided as a standard, characterized in that the microstructure is smoothed out.Type: GrantFiled: November 12, 1999Date of Patent: December 25, 2001Assignee: Wacker Siltronic Gesellschaft für Halbleitermaterialien AGInventors: Rüdiger Schmolke, Dieter Gräf, Robert Kerschreiter, Hans-Adolf Gerber, Anton Luger, Monique Suhren
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Patent number: 6228164Abstract: 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: GrantFiled: May 25, 1999Date of Patent: May 8, 2001Assignee: Wacker Siltronic Gesellschaft für Halbleitermaterialien AGInventors: Wilfried von Ammon, Rüdiger Schmolke, Dieter Gräf, Ulrich Lambert
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Patent number: 5935320Abstract: 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: GrantFiled: August 26, 1997Date of Patent: August 10, 1999Assignee: Wacker Siltronic Gesellschaft fur Halbleitermaterialien AGInventors: Dieter Graef, Wilfried Von Ammon, Reinhold Wahlich, Peter Krottenthaler, Ulrich Lambert
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Patent number: 5352637Abstract: A process for producing silicon wafers which have a storage-stable surface and which can be thermally oxidized directly, that is to say, without a prior HF immersion bath, and without the addition of halogen-containing gases, it being possible to achieve an equal or better oxidation result than that achieved by including these measures.Type: GrantFiled: October 14, 1992Date of Patent: October 4, 1994Assignee: Wacker-Chemitronic Gesellschaft fur Elektronik-Grundstoffe mbHInventors: Laszlo Fabry, Manfred Grundner, Dieter Graef, Susanne Bauer-Mayer, Peter John
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Patent number: 4739929Abstract: A fuel injection valve having a piezoceramic valve body, comprising a plurality of superposed ceramic plates each having one conductor layer on each side and voltage leads to the conductor layers. Each ceramic plate is arranged on a carrier plate. Between each unit, consisting of a ceramic plate and a carrier plate, an insulating foil is provided with conductor foils arranged on each side as conductor layers. Each insulating foil comprises two terminal lugs. Each insulating foil, in the region of a terminal lug, is laminated on one side with one conductor foil. The correlated termial lugs are connected in each case to an electrical contact for the correlated conductor foils.Type: GrantFiled: September 9, 1986Date of Patent: April 26, 1988Assignee: Atlas Fahrzeugtechnik GmbHInventors: Burkhard Brandner, Dieter Graef, Klaus Wenzlik