公开(公告)号：US11385553B2

公开(公告)日：2022-07-12

申请号：US17306670

申请日：2021-05-03

Applicant: ASML Netherlands B.V.

Inventor： Zili Zhou ,  Nitesh Pandey ,  Olger Victor Zwier ,  Patrick Warnaar ,  Maurits Van Der Schaar ,  Elliott Gerard McNamara ,  Arie Jeffrey Den Boef ,  Paul Christiaan Hinnen ,  Murat Bozkurt ,  Joost Jeroen Ottens ,  Kaustuve Bhattacharyya ,  Michael Kubis

IPC: G03F7/20 ,  G01N21/47 ,  G01N21/95 ,  G01N21/956 ,  G03F9/00

Abstract: A method of measuring overlay uses a plurality of asymmetry measurements from locations (LOI) on a pair of sub-targets (1032, 1034) formed on a substrate (W). For each sub-target, the plurality of asymmetry measurements are fitted to at least one expected relationship (1502, 1504) between asymmetry and overlay, based on a known bias variation deigned into the sub-targets. Continuous bias variation in one example is provided by varying the pitch of top and bottom gratings (P1/P2). Bias variations between the sub-targets of the pair are equal and opposite (P2/P1). Overlay (OV) is calculated based on a relative shift (xs) between the fitted relationships for the two sub-targets. The step of fitting asymmetry measurements to at least one expected relationship includes wholly or partially discounting measurements (1506, 1508, 1510) that deviate from the expected relationship and/or fall outside a particular segment of the fitted relationship.

公开(公告)号：US10794693B2

公开(公告)日：2020-10-06

申请号：US16102145

申请日：2018-08-13

Applicant: ASML Netherlands B.V.

Inventor： Farzad Farhadzadeh ,  Mohammadreza Hajiahmadi ,  Maurits Van Der Schaar ,  Murat Bozkurt

IPC: G01B11/27 ,  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：US10564552B2

公开(公告)日：2020-02-18

申请号：US16007112

申请日：2018-06-13

Applicant: ASML Netherlands B.V.

Inventor： Gonzalo Roberto Sanguinetti ,  Murat Bozkurt ,  Maurits Van Der Schaar ,  Arie Jeffrey Den Boef

IPC: G03B27/42 ,  G03F7/20 ,  G01B11/27

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.

公开(公告)号：US20200050114A1

公开(公告)日：2020-02-13

申请号：US16655434

申请日：2019-10-17

Applicant: ASML Netherlands B.V.

Inventor： Murat Bozkurt ,  Maurits Van Der Schaar ,  Patrick Warnaar ,  Martin Jacobus Johan Jak ,  Mohammadreza Hajiahmadi ,  Grzegorz Grzela ,  Lukasz Jerzy Macht

IPC: G03F7/20 ,  G01N21/95 ,  G01N21/956 ,  G01N21/47

Abstract: An overlay metrology target (600, 900, 1000) contains a plurality of overlay gratings (932-935) formed by lithography. First diffraction signals (740(1)) are obtained from the target, and first asymmetry values (As) for the target structures are derived. Second diffraction signals (740(2)) are obtained from the target, and second asymmetry values (As′) are derived. The first and second diffraction signals are obtained using different capture conditions and/or different designs of target structures and/or bias values. The first asymmetry signals and the second asymmetry signals are used to solve equations and obtain a measurement of overlay error. The calculation of overlay error makes no assumption whether asymmetry in a given target structure results from overlay in the first direction, in a second direction or in both directions. With a suitable bias scheme the method allows overlay and other asymmetry-related properties to be measured accurately, even in the presence of two-dimensional overlay structure.

公开(公告)号：US20200033741A1

公开(公告)日：2020-01-30

申请号：US16593132

申请日：2019-10-04

Applicant: ASML Netherlands B.V

Inventor： Maurits Van Der Schaar ,  Murat Bozkurt ,  Patrick Warnaar ,  Stefan Cornelis Theodorus Van Der Sanden

IPC: G03F9/00 ,  G03F7/20 ,  G01N21/956

Abstract: A method and apparatus are described for providing an accurate and robust measurement of a lithographic characteristic or metrology parameter. The method includes providing a range or a plurality of values for each of a plurality of metrology parameters of a metrology target, providing a constraint for each of the plurality of metrology parameters, and calculating, by a processor to optimize/modify these parameters within the range of the plurality of values, resulting in a plurality of metrology target designs having metrology parameters meeting the constraints.

公开(公告)号：US09633427B2

公开(公告)日：2017-04-25

申请号：US14839325

申请日：2015-08-28

Applicant: ASML NETHERLANDS B.V.

Inventor： Murat Bozkurt ,  Martin Jacobus Johan Jak ,  Patricius Aloysius Jacobus Tinnemans

IPC: G06K9/62 ,  G06T7/00 ,  G03F7/20

CPC classification number: G06T7/0004 ,  G03F7/705 ,  G03F7/70591 ,  G03F7/70633 ,  G06T7/11 ,  G06T2207/10061 ,  G06T2207/20224 ,  G06T2207/30148

Abstract: A property of a target structure is measured based on intensity of an image of the target. The method includes (a) obtaining an image of the target structure; (b) defining (1204) a plurality of candidate regions of interest, each candidate region of interest comprising a plurality of pixels in the image; (c) defining (1208, 1216) an optimization metric value for the candidate regions of interest based at least partly on signal values of pixels within the region of interest; (d) defining (1208, 1216) a target signal function which defines a contribution of each pixel in the image to a target signal value. The contribution of each pixel depends on (i) which candidate regions of interest contain that pixel and (ii) optimization metric values of those candidate regions of interest.