公开(公告)号：US10996570B2

公开(公告)日：2021-05-04

申请号：US16594613

申请日：2019-10-07

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：US10983445B2

公开(公告)日：2021-04-20

申请号：US16268564

申请日：2019-02-06

Applicant: ASML NETHERLANDS B.V.

Inventor： Nitesh Pandey ,  Zili Zhou ,  Gerbrand Van Der Zouw ,  Arie Jeffrey Den Boef ,  Markus Gerardus Martinus Maria Van Kraaij ,  Armand Eugene Albert Koolen ,  Hugo Augustinus Joseph Cramer ,  Paul Christiaan Hinnen ,  Martinus Hubertus Maria Van Weert ,  Anagnostis Tsiatmas ,  Shu-jin Wang ,  Bastiaan Onne Fagginger Auer ,  Alok Verma

IPC: G03F7/20 ,  G01N21/21 ,  G01N21/88

Abstract: An inspection apparatus, method, and system are described herein. An example inspection apparatus includes an optical system and an imaging system. The optical system may be configured to output an illumination beam incident on a target including one or more features, the illumination beam polarized with a first polarization when incident on the target. The imaging system may be configured to obtain intensity data representing at least a portion of the illumination beam scattered by the one or more features, where the portion of the illumination beam has a second polarization orthogonal to the first polarization. The inspection apparatus may be further configured to generate image data representing an image of each of the feature(s) based on the intensity data, and determine a measurement of a parameter of interest associated with the feature(s) based on an amount of the portion of the illumination beam having the second polarization.

公开(公告)号：US10795269B2

公开(公告)日：2020-10-06

申请号：US16170786

申请日：2018-10-25

Applicant: ASML Netherlands B.V.

Inventor： Zili Zhou ,  Gerbrand Van Der Zouw ,  Nitesh Pandey ,  Markus Gerardus Martinus Maria Van Kraaij ,  Martinus Hubertus Maria Van Weert ,  Anagnostis Tsiatmas ,  Sergey Tarabrin ,  Hilko Dirk Bos

IPC: G01J4/00 ,  G03F7/20

Abstract: The disclosure relates to methods of determining a value of a parameter of interest of a patterning process, and of cleaning a signal containing information about the parameter of interest. In one arrangement, first and second detected representations of radiation are obtained. The radiation is provided by redirection of polarized incident radiation by a structure. The first and second detected representations are derived respectively from first and second polarization components of the redirected radiation. An asymmetry in the first detected representation comprises a contribution from the parameter of interest and a contribution from one or more other sources of asymmetry. An asymmetry in the second detected representation comprises a larger contribution from said one or more other sources of asymmetry relative to a contribution from the parameter of interest. A combination of the first and second detected representations is used to determine a value of the parameter of interest.

公开(公告)号：US10747124B2

公开(公告)日：2020-08-18

申请号：US16441832

申请日：2019-06-14

Applicant: ASML Netherlands B.V.

Inventor： Nitesh Pandey ,  Zili Zhou

IPC: G03F7/20

Abstract: Methods of measuring a target formed by a lithographic process, a metrology apparatus and a polarizer assembly are disclosed. The polarizer assembly comprises a polarizing structure having a substantially planar form and configured to polarize radiation passing there through in a circular polarizing region. The circular polarizing region is configured to apply a first polarization to radiation passing through a first one of two pairs of diametrically opposite quadrants of the circular polarizing region and to apply a second polarization, orthogonal to the first polarization, to radiation passing through a second one of two pairs of diametrically opposite quadrants of the circular polarizing region.

公开(公告)号：US20190146356A1

公开(公告)日：2019-05-16

申请号：US16223372

申请日：2018-12-18

Applicant: ASML Netherlands B.V.

Inventor： Nitesh Pandey ,  Zili Zhou ,  Armand Eugene Albert Koolen ,  Gerbrand Van Der Zouw

IPC: G03F7/20 ,  G01B11/27 ,  G01N21/47

CPC classification number: G03F7/70625 ,  G01B11/272 ,  G01N21/47 ,  G03F7/7015 ,  G03F7/706 ,  G03F7/70633

Abstract: Disclosed is a metrology apparatus for measuring a parameter of a lithographic process, and associated computer program and method. The metrology apparatus comprises an optical system for measuring a target on a substrate by illuminating the target with measurement radiation and detecting the measurement radiation scattered by the target; and an array of lenses. Each lens of the array is operable to focus the scattered measurement radiation onto a sensor, said array of lenses thereby forming an image on the sensor which comprises a plurality of sub-images, each sub-image being formed by a corresponding lens of the array of lenses. The resulting plenoptic image comprises image plane information from the sub-images, wavefront distortion information (from the relative positions of the sub-images) and pupil information from the relative intensities of the sub-images.

公开(公告)号：US20180157180A1

公开(公告)日：2018-06-07

申请号：US15830775

申请日：2017-12-04

Applicant: ASML Netherlands B.V.

Inventor： Nitesh Pandey ,  Zili Zhou

IPC: G03F7/20

CPC classification number: G03F7/70591 ,  G03F7/70633

Abstract: Methods of measuring a target formed by a lithographic process, a metrology apparatus and a polarizer assembly are disclosed. The target comprises a layered structure having a first periodic structure in a first layer and a second periodic structure in a second layer. The target is illuminated with polarized measurement radiation. Zeroth order scattered radiation from the target is detected. An asymmetry in the first periodic structure is derived using the detected zeroth order scattered radiation from the target. A separation between the first layer and the second layer is such that the detected zeroth order scattered radiation is independent of overlay error between the first periodic structure and the second periodic structure. The derived asymmetry in the first periodic structure is used to derive the correct overlay value between the first periodic structure and the second periodic structure.

公开(公告)号：US11042100B2

公开(公告)日：2021-06-22

申请号：US16410250

申请日：2019-05-13

Applicant: ASML Netherlands B.V.

Inventor： Jin Lian ,  Zili Zhou ,  Duygu Akbulut ,  Sergey Tarabrin

IPC: G03F7/20

Abstract: The disclosure relates to measuring a target. In one arrangement, a measurement apparatus is provided that has an optical system configured to illuminate a target with radiation and direct reflected radiation from the target to a sensor. A programmable spatial light modulator in a pupil plane of the optical system is programmed to redirect light in each of a plurality of pupil plane zones in such a way as to form a corresponding plurality of images at different locations on the sensor. Each image is formed by radiation passing through a different respective one of the pupil plane zones.

公开(公告)号：US10353298B2

公开(公告)日：2019-07-16

申请号：US15830775

申请日：2017-12-04

Applicant: ASML Netherlands B.V.

Inventor： Nitesh Pandey ,  Zili Zhou

IPC: G03F7/20

Abstract: Methods of measuring a target formed by a lithographic process, a metrology apparatus and a polarizer assembly are disclosed. The target comprises a layered structure having a first periodic structure in a first layer and a second periodic structure in a second layer. The target is illuminated with polarized measurement radiation. Zeroth order scattered radiation from the target is detected. An asymmetry in the first periodic structure is derived using the detected zeroth order scattered radiation from the target. A separation between the first layer and the second layer is such that the detected zeroth order scattered radiation is independent of overlay error between the first periodic structure and the second periodic structure. The derived asymmetry in the first periodic structure is used to derive the correct overlay value between the first periodic structure and the second periodic structure.

公开(公告)号：US10191391B2

公开(公告)日：2019-01-29

申请号：US15279860

申请日：2016-09-29

Applicant: ASML Netherlands B.V.

Inventor： Nitesh Pandey ,  Zili Zhou ,  Armand Eugene Albert Koolen ,  Gerbrand Van Der Zouw

IPC: G03B27/42 ,  G03F7/20 ,  G01B11/27 ,  G01N21/47

Abstract: Disclosed is a metrology apparatus for measuring a parameter of a lithographic process, and associated computer program and method. The metrology apparatus comprises an optical system for measuring a target on a substrate by illuminating the target with measurement radiation and detecting the measurement radiation scattered by the target; and an array of lenses. Each lens of the array is operable to focus the scattered measurement radiation onto a sensor, said array of lenses thereby forming an image on the sensor which comprises a plurality of sub-images, each sub-image being formed by a corresponding lens of the array of lenses. The resulting plenoptic image comprises image plane information from the sub-images, wavefront distortion information (from the relative positions of the sub-images) and pupil information from the relative intensities of the sub-images.

公开(公告)号：US20180348645A1

公开(公告)日：2018-12-06

申请号：US15988677

申请日：2018-05-24

Applicant: ASML Netherlands B.V.

Inventor： Janneke Ravensbergen ,  Nitesh Pandey ,  Zili Zhou ,  Armand Eugene Albert Koolen ,  Sebastianus Adrianus Goorden ,  Bastiaan Onne Fagginger Auer ,  Simon Gijsbert Josephus Mathijssen

IPC: G03F7/20 ,  G01B11/27

CPC classification number: G03F7/7055 ,  G01B11/272 ,  G01N21/4788 ,  G01N21/9501 ,  G01N21/95623 ,  G03F7/70625 ,  G03F7/70633

Abstract: A metrology apparatus is disclosed that measures a structure formed on a substrate to determine a parameter of interest. The apparatus comprises an optical system configured to focus radiation onto the structure and direct radiation after reflection from the structure onto a detector, wherein: the optical system is configured such that the detector detects a radiation intensity resulting from interference between radiation from at least two different points in a pupil plane field distribution, wherein the interference is such that a component of the detected radiation intensity containing information about the parameter of interest is enhanced relative to one or more other components of the detected radiation intensity.