Patents by Inventor Masamichi OOKUBO

Masamichi OOKUBO 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).

  • Method for producing a semiconductor wafer of monocrystalline silicon, device for producing a semiconductor wafer of monocrystalline silicon and semiconductor wafer of monocrystalline
    Patent number: 10844513
    Abstract: Single crystal semiconductor wafers comprise oxygen and an n-type dopant, and are produced by a process comprising providing a silicon melt containing n-type dopant in a quartz crucible, the melt having an initial height hM; heating the melt from the side by selectively supplying heat to an upper volume of the melt having an initial height hm, wherein hm is smaller than hM; pulling a single crystal of silicon from the melt by the CZ method with a pulling velocity V; heating the melt from above in the region of a phase boundary between the growing single crystal and the melt; heating the melt from above in the region of a surface of the melt; subjecting the melt to a magnetic field; counterdoping the melt with p-type dopant; and separating the semiconductor wafer of single-crystal silicon from the single crystal. An apparatus for accomplishing the process is also disclosed.
    Type: Grant
    Filed: May 17, 2017
    Date of Patent: November 24, 2020
    Assignee: SILTRONIC AG
    Inventors: Walter Heuwieser, Dieter Knerer, Werner Schachinger, Masamichi Ookubo
  • METHOD FOR PRODUCING A SEMICONDUCTOR WAFER OF MONOCRYSTALLINE SILICON, DEVICE FOR PRODUCING A SEMICONDUCTOR WAFER OF MONOCRYSTALLINE SILICON AND SEMICONDUCTOR WAFER OF MONOCRYSTALLINE SILICON
    Publication number: 20190136404
    Abstract: Single crystal semiconductor wafers comprise oxygen and an n-type dopant, and are produced by a process comprising providing a silicon melt containing n-type dopant in a quartz crucible, the melt having an initial height hM; heating the melt from the side by selectively supplying heat to an upper volume of the melt having an initial height hm, wherein hm is smaller than hM; pulling a single crystal of silicon from the melt by the CZ method with a pulling velocity V; heating the melt from above in the region of a phase boundary between the growing single crystal and the melt; heating the melt from above in the region of a surface of the melt; subjecting the melt to a magnetic field; counterdoping the melt with p-type dopant; and separating the semiconductor wafer of single-crystal silicon from the single crystal. An apparatus for accomplishing the process is also disclosed.
    Type: Application
    Filed: May 17, 2017
    Publication date: May 9, 2019
    Applicant: SILTRONIC AG
    Inventors: Walter HEUWIESER, Dieter KNERER, Werner SCHACHINGER, Masamichi OOKUBO