Patents by Inventor Yun-Chang Choi

Yun-Chang Choi 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 manufacturing gallium nitride quantum dots doped with metal ions
    Patent number: 12269737
    Abstract: The present invention relates to a method of manufacturing gallium nitride quantum dots, and more particularly, to a method of manufacturing gallium nitride quantum dots doped with metal ions, which uses a wet-based synthesis method capable of lowering the fluorescence energy of pure gallium nitride by introducing metal ions into pure gallium nitride.
    Type: Grant
    Filed: May 8, 2019
    Date of Patent: April 8, 2025
    Assignee: Korea University Research and Business Foundation
    Inventors: Kwang Seob Jeong, Yun Chang Choi
  • Apparatus for inspecting a wafer
    Patent number: 7079237
    Abstract: An apparatus for inspecting a wafer includes a handling unit for supporting, rotating and moving the wafer in horizontal and vertical directions, a first image acquisition unit for acquiring a first image corresponding to an upper surface of the wafer supported by the handling unit, a second image acquisition unit for acquiring a second image, a third image and a fourth image corresponding to a peripheral portion of the upper surface, a side surface and a lower surface of the wafer supported by the handling unit, respectively, a first driving unit for rotating the second image acquisition unit about a peripheral portion of the wafer supported by the handling unit in order to acquiring the second, third and fourth images, and an image processing unit for inspecting defects of the wafer supported by the handling unit from the first to fourth images.
    Type: Grant
    Filed: October 8, 2003
    Date of Patent: July 18, 2006
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jai-Young Woo, Kyung-Ho Kim, Yun-Chang Choi, Hye-Jung Choi, Sung-Uk Park
  • Apparatus for inspecting a wafer
    Publication number: 20040095575
    Abstract: An apparatus for inspecting a wafer includes a handling unit for supporting, rotating and moving the wafer in horizontal and vertical directions, a first image acquisition unit for acquiring a first image corresponding to an upper surface of the wafer supported by the handling unit, a second image acquisition unit for acquiring a second image, a third image and a fourth image corresponding to a peripheral portion of the upper surface, a side surface and a lower surface of the wafer supported by the handling unit, respectively, a first driving unit for rotating the second image acquisition unit about a peripheral portion of the wafer supported by the handling unit in order to acquiring the second, third and fourth images, and an image processing unit for inspecting defects of the wafer supported by the handling unit from the first to fourth images.
    Type: Application
    Filed: October 8, 2003
    Publication date: May 20, 2004
    Inventors: Jai-Young Woo, Kyung-Ho Kim, Yun-Chang Choi, Hye-Jung Choi, Sung-Uk Park