公开(公告)号：EP3444676A1

公开(公告)日：2019-02-20

申请号：EP17186295.6

申请日：2017-08-15

Applicant: ASML Netherlands B.V.

Inventor： FARHADZADEH, Farzad ,  HAJIAHMADI, Mohammadreza ,  VAN DER SCHAAR, Maurits ,  BOZKURT, Murat

IPC: G03F7/20

Abstract: Disclosed is a method and associated apparatus of determining a performance parameter (e.g., overlay) of a target on a substrate, and an associated metrology apparatus. The method comprises estimating a set of narrowband measurement values from a set of wideband measurement values relating to the target and determining the performance parameter from said set of narrowband measurement values. The wideband measurement values relate to measurements of the target performed using wideband measurement radiation and may correspond to different central wavelengths. The narrowband measurement values may comprise an estimate of the measurement values which would be obtained from measurement of the target using narrowband measurement radiation having a bandwidth narrower than said wideband measurement radiation.

公开(公告)号：EP3470923A1

公开(公告)日：2019-04-17

申请号：EP17195664.2

申请日：2017-10-10

Applicant: ASML Netherlands B.V.

Inventor： JAVAHERI, Narjes ,  HAJIAHMADI, Mohammadreza ,  BOZKURT, Murat ,  DA COSTA ASSAFRAO, Alberto

IPC: G03F7/20

Abstract: Disclosed is a method, and associated apparatuses, for measuring a parameter of interest relating to a structure having at least two layers. The method comprises illuminating the structure with measurement radiation and detecting scattered radiation having been scattered by said structure. The scattered radiation comprises normal and complementary higher diffraction orders. A scatterometry model which relates a scattered radiation parameter to at least a parameter of interest and an asymmetry model which relates the scattered radiation parameter to at least one asymmetry parameter are defined, the asymmetry parameter relating to one or more measurement system errors and/or an asymmetry in the target other than a misalignment between the two layers. A combination of the scatterometry model and asymmetry model is used to determine a system of equations, and the system of equations is then solved for the parameter of interest.

公开(公告)号：EP3422103A1

公开(公告)日：2019-01-02

申请号：EP17177953.1

申请日：2017-06-26

Applicant: ASML Netherlands B.V.

Inventor： SANGUINETTI, Gonzalo Roberto ,  BOZKURT, Murat ,  VAN DER SCHAAR, Maurits ,  DEN BOEF, Arie Jeffrey

IPC: G03F7/20

Abstract: Overlay error of a lithographic process is measured using a plurality of target structures, each target structure having a known overlay bias. A detection system captures a plurality of images (740) representing selected portions of radiation diffracted by the target structures under a plurality of different capture conditions (λ1, λ2). Pixel values of the captured images are combined (748) to obtain one or more synthesized images (750). A plurality of synthesized diffraction signals are extracted (744) from the synthesized image or images, and used to calculate a measurement of overlay. The computational burden is reduced compared with extracting diffraction signals from the captured images individually. The captured images may be dark-field images or pupil images, obtained using a scatterometer.