Patents by Inventor Keng-Fu CHANG

Keng-Fu CHANG 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 and system for determining information about a target structure
    Patent number: 12061421
    Abstract: Methods and systems for determining information about a target structure are disclosed. In one arrangement, a value of an asymmetry indicator for the target structure is obtained. The value of the asymmetry indicator represents an amount of an overlay independent asymmetry in the target structure. An error in an initial overlay measurement performed on the target structure at a previous time is estimated. The estimation is performed using the obtained value of the asymmetry indicator and a relationship between values of the asymmetry indicator and overlay measurement errors caused at least partially by overlay independent asymmetries. An overlay in the target structure is determined using the initial overlay measurement and the estimated error.
    Type: Grant
    Filed: July 17, 2020
    Date of Patent: August 13, 2024
    Assignee: ASML Netherlands B.V.
    Inventors: Arie Jeffrey Den Boef, Kaustuve Bhattacharyya, Keng-Fu Chang, Simon Gijsbert Josephus Mathijssen
  • METHOD AND SYSTEM FOR DETERMINING INFORMATION ABOUT A TARGET STRUCTURE
    Publication number: 20220276569
    Abstract: Methods and systems for determining information about a target structure are disclosed. In one arrangement, a value of an asymmetry indicator for the target structure is obtained. The value of the asymmetry indicator represents an amount of an overlay independent asymmetry in the target structure. An error in an initial overlay measurement performed on the target structure at a previous time is estimated. The estimation is performed using the obtained value of the asymmetry indicator and a relationship between values of the asymmetry indicator and overlay measurement errors caused at least partially by overlay independent asymmetries. An overlay in the target structure is determined using the initial overlay measurement and the estimated error.
    Type: Application
    Filed: July 17, 2020
    Publication date: September 1, 2022
    Applicant: ASML Netherlands B.V.
    Inventors: Arie Jeffrey DEN BOEF, Kaustuve BHATTACHARYYA, Keng-Fu CHANG, Simon Gijsbert Josephus MATHIJSSEN