公开(公告)号：US20240337952A1

公开(公告)日：2024-10-10

申请号：US18372444

申请日：2023-09-25

Applicant: KLA Corporation

Inventor： Itay Gdor ,  Yonatan Vaknin ,  Nireekshan K. Reddy ,  Alon Alexander Volfman ,  Iftach Galon ,  Jordan Pio ,  Yuval Lubashevsky ,  Nickolai Isakovitch ,  Andrew V. Hill ,  Oren Lahav ,  Daria Negri ,  Vladimir Levinski

IPC: G03F7/00

CPC classification number: G03F7/70633 ,  G03F7/7015

Abstract: A method may include receiving time-varying interference signals from two or more photodetectors associated with a first exposure structure and a second exposure structure in one or more cells as an overlay target is scanned in accordance with a metrology recipe, where the first exposure structure and the second exposure structure form a side-by-side grating, where the side-by-side grating includes one or more diffraction gratings, where at least one diffraction grating is a non-overlapping side-by-side grating, where the first exposure structure is arranged adjacent to the second exposure structure, where the side-by-side grating is periodic along the scan direction. The method may further include determining an overlay error between one of the first exposure structure and the second exposure structure of the sample based on the time-varying interference signals, where the time-varying interference signals corresponding to the non-overlapping first exposure structure and second exposure structure are synchronized.