Patents by Inventor Huaihua XU

Huaihua XU 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).

  • Trench gate structure and method of forming a trench gate structure
    Patent number: 11456367
    Abstract: The present invention provides a trench gate structure and a method of forming the same. The method comprises steps of forming a first trench on the surface of a substrate, a surface of a bottom of the first trench comprising a crystal face belonging to the first family of crystal faces, and a surface of a sidewall of the first trench comprising another crystal face belonging to a second family of crystal faces. With a face-selective wet etching, a specific crystal face is presented on the surface of the bottom of the trench and a thicker gate oxide layer is formed thereon after performing thermal oxidation to avoid from failure due to thinner gate oxide layer on the surface of the bottom, increase breakdown voltage, and improve reliability of the device.
    Type: Grant
    Filed: April 28, 2021
    Date of Patent: September 27, 2022
    Assignee: SiEn (QingDao) Integrated Circuits Co., Ltd.
    Inventors: Min-Hwa Chi, Longkang Yang, Huaihua Xu, Huan Wang, Richard Ru-Gin Chang
  • TRENCH GATE STRUCTURE AND METHOD OF FORMING A TRENCH GATE STRUCTURE
    Publication number: 20210343850
    Abstract: The present invention provides a trench gate structure and a method of forming the same. The method comprises steps of forming a first trench on the surface of a substrate, a surface of a bottom of the first trench comprising a crystal face belonging to the first family of crystal faces, and a surface of a sidewall of the first trench comprising another crystal face belonging to a second family of crystal faces. With a face-selective wet etching, a specific crystal face is presented on the surface of the bottom of the trench and a thicker gate oxide layer is formed thereon after performing thermal oxidation to avoid from failure due to thinner gate oxide layer on the surface of the bottom, increase breakdown voltage, and improve reliability of the device.
    Type: Application
    Filed: April 28, 2021
    Publication date: November 4, 2021
    Applicant: SiEn (QingDao) Integrated Circuits Co., Ltd.
    Inventors: Min-Hwa CHI, Longkang YANG, Huaihua XU, Huan WANG, Richard Ru-Gin CHANG