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：US10725386B2

公开(公告)日：2020-07-28

申请号：US16421697

申请日：2019-05-24

Applicant: ASML Netherlands B.V.

Inventor： Scott Anderson Middlebrooks ,  Niels Geypen ,  Hendrik Jan Hidde Smilde ,  Alexander Straaijer ,  Maurits Van Der Schaar ,  Markus Gerardus Martinus Maria Van Kraaij

IPC: G03F7/20

Abstract: Disclosed is a method of measuring a parameter of a lithographic process, and associated inspection apparatus. The method comprises measuring at least two target structures on a substrate using a plurality of different illumination conditions, the target structures having deliberate overlay biases; to obtain for each target structure an asymmetry measurement representing an overall asymmetry that includes contributions due to (i) the deliberate overlay biases, (ii) an overlay error during forming of the target structure and (iii) any feature asymmetry. A regression analysis is performed on the asymmetry measurement data by fitting a linear regression model to a planar representation of asymmetry measurements for one target structure against asymmetry measurements for another target structure, the linear regression model not necessarily being fitted through an origin of the planar representation. The overlay error can then be determined from a gradient described by the linear regression model.

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：US10474039B2

公开(公告)日：2019-11-12

申请号：US15384084

申请日：2016-12-19

Applicant: ASML Netherlands B.V.

Inventor： Paul Christiaan Hinnen ,  Simon Gijsbert Josephus Mathijssen ,  Maikel Robert Goosen ,  Maurits Van Der Schaar ,  Arie Jeffrey Den Boef

IPC: G03B27/34 ,  G03F7/20

Abstract: A lithographic apparatus (LA) prints product features and at least one focus metrology pattern (T) on a substrate. The focus metrology pattern is defined by a reflective reticle and printing is performed using EUV radiation (404) incident at an oblique angle (θ). The focus metrology pattern comprises a periodic array of groups of first features (422). A spacing (S1) between adjacent groups of first features is much greater than a dimension (CD) of the first features within each group. Due to the oblique illumination, the printed first features become distorted and/or displaced as a function of focus error. Second features 424 may be provided as a reference against which displacement of the first features may be seen. Measurement of this distortion and/or displacement may be by measuring asymmetry as a property of the printed pattern. Measurement can be done at longer wavelengths, for example in the range 350-800 nm.

公开(公告)号：US09910366B2

公开(公告)日：2018-03-06

申请号：US14906896

申请日：2014-07-18

Applicant: ASML Netherlands B.V.

Inventor： Scott Anderson Middlebrooks ,  Niels Geypen ,  Hendrik Jan Hidde Smilde ,  Alexander Straaijer ,  Maurits Van Der Schaar ,  Markus Gerardus Martinus Maria Van Kraaij

IPC: G03F7/20

CPC classification number: G03F7/70633

Abstract: Disclosed is a method of measuring a parameter of a lithographic process, and associated inspection apparatus. The method comprises measuring at least two target structures on a substrate using a plurality of different illumination conditions, the target structures having deliberate overlay biases; to obtain for each target structure an asymmetry measurement representing an overall asymmetry that includes contributions due to (i) the deliberate overlay biases, (ii) an overlay error during forming of the target structure and (iii) any feature asymmetry. A regression analysis is performed on the asymmetry measurement data by fitting a linear regression model to a planar representation of asymmetry measurements for one target structure against asymmetry measurements for another target structure, the linear regression model not necessarily being fitted through an origin of the planar representation. The overlay error can then be determined from a gradient described by the linear regression model.

公开(公告)号：US20170314915A1

公开(公告)日：2017-11-02

申请号：US15649173

申请日：2017-07-13

Applicant: ASML Netherlands B.V.

Inventor： Maurits Van Der Schaar ,  Kaustuve Bhattacharyya ,  Hendrik-Jan Hidde Smilde

IPC: G01B11/27 ,  G03F7/20 ,  G01B11/30 ,  H01L23/544

CPC classification number: G01B11/27 ,  G01B11/30 ,  G03F7/20 ,  G03F7/70633 ,  H01L23/544 ,  H01L2924/0002 ,  H01L2924/00

Abstract: A lithographic process is used to form a plurality of target structures distributed at a plurality of locations across a substrate and having overlaid periodic structures with a number of different overlay bias values distributed across the target structures. At least some of the target structures comprising a number of overlaid periodic structures (e.g., gratings) that is fewer than said number of different overlay bias values. Asymmetry measurements are obtained for the target structures. The detected asymmetries are used to determine parameters of a lithographic process. Overlay model parameters including translation, magnification and rotation, can be calculated while correcting the effect of bottom grating asymmetry, and using a multi-parameter model of overlay error across the substrate.

公开(公告)号：US09714827B2

公开(公告)日：2017-07-25

申请号：US14412771

申请日：2013-06-17

Applicant: ASML Netherlands B.V.

Inventor： Maurits Van Der Schaar ,  Kaustuve Bhattacharyya ,  Hendrik-Jan Hidde Smilde

IPC: H01L23/544 ,  G01B11/27 ,  G03F7/20 ,  G01B11/30

CPC classification number: G01B11/27 ,  G01B11/30 ,  G03F7/20 ,  G03F7/70633 ,  H01L23/544 ,  H01L2924/0002 ,  H01L2924/00

Abstract: A lithographic process is used to form a plurality of target structures (92, 94) distributed at a plurality of locations across a substrate and having overlaid periodic structures with a number of different overlay bias values distributed across the target structures. At least some of the target structures comprise a number of overlaid periodic structures (e.g., gratings) that is fewer than said number of different overlay bias values. Asymmetry measurements are obtained for the target structures. The detected asymmetries are used to determine parameters of a lithographic process. Overlay model parameters including translation, magnification and rotation, can be calculated while correcting the effect of bottom grating asymmetry, and using a multi-parameter model of overlay error across the substrate.

公开(公告)号：US09158194B2

公开(公告)日：2015-10-13

申请号：US13628697

申请日：2012-09-27

Applicant: ASML Netherlands B.V.

Inventor： Armand Eugene Albert Koolen ,  Henricus Petrus Maria Pellemans ,  Maurits Van Der Schaar ,  Peter Clement Paul Vanoppen ,  Michael Kubis

IPC: G01B11/00 ,  G01B11/14 ,  G03B27/32 ,  G03B27/54 ,  G03B27/72 ,  G03B27/74 ,  G03C5/00 ,  G03F1/42 ,  G03F7/20 ,  G03F9/00 ,  G01N21/47 ,  G01B9/04

CPC classification number: G03F1/42 ,  G01B9/04 ,  G01N21/47 ,  G03F7/70616 ,  G03F7/70633 ,  G03F9/70 ,  G03F9/7069 ,  G03F9/7088

Abstract: An approach is used to estimate and correct the overlay variation as function of offset for each measurement. A target formed on a substrate includes periodic gratings. The substrate is illuminated with a circular spot on the substrate with a size larger than each grating. Radiation scattered by each grating is detected in a dark-field scatterometer to obtain measurement signals. The measurement signals are used to calculate overlay. The dependence (slope) of the overlay as a function of position in the illumination spot is determined. An estimated value of the overlay at a nominal position such as the illumination spot's center can be calculated, correcting for variation in the overlay as a function of the target's position in the illumination spot. This compensates for the effect of the position error in the wafer stage movement, and the resulting non-centered position of the target in the illumination spot.

Abstract translation: 一种方法用于估计和校正覆盖变化作为每个测量的偏移函数。 形成在衬底上的靶包括周期性光栅。 在衬底上用圆形点照射衬底，其尺寸大于每个光栅。 在暗场散射仪中检测由每个光栅散射的辐射，以获得测量信号。 测量信号用于计算叠加。 确定覆盖层与照明点中位置的函数关系（斜率）。 可以计算在诸如照明点中心的标称位置处的覆盖物的估计值，以根据目标在照明点中的位置的函数来校正覆盖物的变化。 这补偿了晶片台移动中的位置误差的影响，以及目标在照明点中产生的非居中位置。