Patents by Inventor Qiang Y. Zhang

Qiang Y. Zhang 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).

  • Wave-Front Aberration Metrology of Extreme Ultraviolet Mask Inspection Systems
    Publication number: 20200379336
    Abstract: A metrology system for measuring wave-front aberration of an extreme ultraviolet (EUV) mask inspection system is disclosed. The test mask includes a substrate formed from a material having substantially no reflectivity for EUV illumination, and one or more patterns formed on the substrate, the one or more patterns having a reflective portion configured to reflect EUV illumination, positioned in a common plane with an absorption portion having substantially no reflectivity for EUV illumination, on or above the substrate.
    Type: Application
    Filed: May 1, 2020
    Publication date: December 3, 2020
    Inventors: Dmitriy Zusin, Rui-fang Shi, Qiang Y. Zhang