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).

  • Patent number: 8323403
    Abstract: 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: Grant
    Filed: January 18, 2008
    Date of Patent: December 4, 2012
    Assignee: Siltronic AG
    Inventors: Dieter Graef, Markus Blietz, Reinhold Wahlich, Alfred Miller, Dirk Zemke
  • Patent number: 7394129
    Abstract: 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: Grant
    Filed: April 13, 2005
    Date of Patent: July 1, 2008
    Assignee: Siltronic AG
    Inventors: Dieter Gräf, Markus Blietz, Reinhold Wahlich, Alfred Miller, Dirk Zemke
  • Publication number: 20080153259
    Abstract: 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: Application
    Filed: January 18, 2008
    Publication date: June 26, 2008
    Applicant: SILTRONIC AG
    Inventors: Dieter Graef, Markus Blietz, Reinhold Wahlich, Alfred Miller, Dirk Zemke
  • Patent number: 6630024
    Abstract: 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: Grant
    Filed: May 24, 2001
    Date of Patent: October 7, 2003
    Assignee: Wacker Siltronic Gesellschaft für Halbleitermaterialien AG
    Inventors: Rüdiger Schmolke, Reinhard Schauer, Günther Obermeier, Dieter Gräf, Peter Storck, Klaus Messmann, Wolfgang Siebert
  • Patent number: 6333785
    Abstract: 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: Grant
    Filed: November 12, 1999
    Date of Patent: December 25, 2001
    Assignee: Wacker Siltronic Gesellschaft für Halbleitermaterialien AG
    Inventors: Rüdiger Schmolke, Dieter Gräf, Robert Kerschreiter, Hans-Adolf Gerber, Anton Luger, Monique Suhren
  • 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: 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
  • Patent number: 5352637
    Abstract: 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: Grant
    Filed: October 14, 1992
    Date of Patent: October 4, 1994
    Assignee: Wacker-Chemitronic Gesellschaft fur Elektronik-Grundstoffe mbH
    Inventors: Laszlo Fabry, Manfred Grundner, Dieter Graef, Susanne Bauer-Mayer, Peter John
  • Patent number: 4739929
    Abstract: 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: Grant
    Filed: September 9, 1986
    Date of Patent: April 26, 1988
    Assignee: Atlas Fahrzeugtechnik GmbH
    Inventors: Burkhard Brandner, Dieter Graef, Klaus Wenzlik