Patents by Inventor Klaus Messmann

Klaus Messmann 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: 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
  • Publication number: 20060213424
    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: Application
    Filed: March 22, 2006
    Publication date: September 28, 2006
    Inventors: Timo Mueller, Wilfried von Ammon, Erich Daub, Peter Krottenthaler, Klaus Messmann, Friedrich Passek, Reinhold Wahlich, Arnold Kuehhorn, Johannes Studener
  • Patent number: 6899762
    Abstract: A semiconductor wafer with a front surface and a back surface and an epitaxial layer of semiconducting material deposited on the front surface. In the semiconductor wafer, the epitaxial layer has a maximum local flatness value SFQRmax of less than or equal to 0.13 ?m and a maximum density of 0.14 scattered light centers per cm2. The front surface of the semiconductor wafer, prior to the deposition of the epitaxial layer, has a surface roughness of 0.05 to 0.29 nm RMS, measured by AFM on a 1 ?m×1 ?m reference area. Furthermore, there is a process for producing the semiconductor wafer.
    Type: Grant
    Filed: March 28, 2003
    Date of Patent: May 31, 2005
    Assignee: Siltronic AG
    Inventors: Guido Wenski, Wolfgang Siebert, Klaus Messmann, Gerhard Heier, Thomas Altmann, Martin Fürfanger
  • 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
  • Publication number: 20030186028
    Abstract: A semiconductor wafer with a front surface and a back surface and an epitaxial layer of semiconducting material deposited on the front surface. In the semiconductor wafer, the epitaxial layer has a maximum local flatness value SFQRmax of less than or equal to 0.13 &mgr;m and a maximum density of 0.14 scattered light centers per cm2. The front surface of the semiconductor wafer, prior to the deposition of the epitaxial layer, has a surface roughness of 0.05 to 0.29 nm RMS, measured by AFM on a 1 &mgr;m×1 &mgr;m reference area. Furthermore, there is a process for producing the semiconductor wafer.
    Type: Application
    Filed: March 28, 2003
    Publication date: October 2, 2003
    Applicant: WACKER SILTRONIC GESELLSCHAFT FUR HABLEITERMATERIALIEN AG
    Inventors: Guido Wenski, Wolfgang Siebert, Klaus Messmann, Gerhard Heier, Thomas Altmann, Martin Furfanger