公开(公告)号：US12061421B2

公开(公告)日：2024-08-13

申请号：US17629053

申请日：2020-07-17

Applicant: ASML Netherlands B.V.

Inventor： Arie Jeffrey Den Boef ,  Kaustuve Bhattacharyya ,  Keng-Fu Chang ,  Simon Gijsbert Josephus Mathijssen

IPC: G03F7/00

CPC classification number: G03F7/70633

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.