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：US10393514B2

公开(公告)日：2019-08-27

申请号：US15764661

申请日：2016-09-05

Applicant: ASML Netherlands B.V.

Inventor： Nitesh Pandey

IPC: G03F7/20 ,  G03F9/00 ,  G01B11/06 ,  G01B11/24 ,  G01B11/25

Abstract: Measurement system comprising a radiation source configured to generate a measurement radiation beam, a polarizer and a grating to receive the measurement radiation beam and provide a polarized measurement radiation beam patterned by the grating, optics to form an image of the grating at a target location on a substrate. The image comprises a first part having a first polarization and a second part having a second polarization, detection optics to receive radiation from the target location of the substrate and form an image of the grating image at a second grating, and a detector to receive radiation transmitted through the second grating and produce a two output signal indicative of the intensity of the transmitted radiation for the first and second parts of the grating image respectively. Topography of the substrate can be determined from the signals.

公开(公告)号：US10365565B2

公开(公告)日：2019-07-30

申请号：US15435593

申请日：2017-02-17

Applicant: ASML Netherlands B.V.

Inventor： Nitesh Pandey ,  Arie Jeffrey Den Boef ,  Marinus Johannes Maria Van Dam

IPC: G03B27/72 ,  G03F7/20 ,  G01N21/47 ,  G02B5/22

Abstract: A scatterometer performs diffraction based measurements of one or more parameters of a target structure. To make two-color measurements in parallel, the structure is illuminated simultaneously with first radiation (302) having a first wavelength and a first angular distribution and with second radiation (304) having a second wavelength and a second angular distribution. The collection path (CP) includes a segmented wavelength-selective filter (21, 310) arranged to transmit wanted higher order portions of the diffracted first radiation (302X, 302Y) and of the diffracted second radiation (304X, 304Y), while simultaneously blocking zero order portions (302″, 304″) of both the first radiation and second radiation. The illumination path (IP) in one embodiment includes a matching segmented wavelength-selective filter (13, 300), oriented such that a zero order ray passing through the illumination optical system and the collection optical system will be blocked by one of said filters or the other, depending on its wavelength.

公开(公告)号：US10310389B2

公开(公告)日：2019-06-04

申请号：US15942423

申请日：2018-03-30

Applicant: ASML NETHERLANDS B.V.

Inventor： Nitesh Pandey ,  Jin Lian ,  Samee Ur Rehman ,  Martin Jacobus Johan Jak

IPC: G01N21/00 ,  G03F7/20 ,  G01B11/02

Abstract: Methods and apparatuses for measuring a plurality of structures formed on a substrate are disclosed. In one arrangement, a method includes obtaining data from a first measurement process. The first measurement process including individually measuring each of the plurality of structures to measure a first property of the structure. A second measurement process is used to measure a second property of each of the plurality of structures. The second measurement process includes illuminating each structure with radiation having a radiation property that is individually selected for that structure using the measured first property for the structure.

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：US20190113452A1

公开(公告)日：2019-04-18

申请号：US16162009

申请日：2018-10-16

Applicant: ASML Netherlands B.V.

Inventor： Maxim Pisarenco ,  Nitesh Pandey ,  Alessandro Polo

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

Abstract: An acoustic scatterometer 502 has an acoustic source 520 operable to project acoustic radiation 526 onto a periodic structure 538 and 540 formed on a substrate 536. An acoustic detector 518 is operable to detect the −1st acoustic diffraction order 528 diffracted by the periodic structure 538 and 540 while discriminating from specular reflection (0th order 532). Another acoustic detector 522 is operable to detect the +1st acoustic diffraction order 530 diffracted by the periodic structure, again while discriminating from the specular reflection (0th order 532). The acoustic source and acoustic detector may be piezo transducers. The angle of incidence of the projected acoustic radiation 526 and location of the detectors 518 and 522 are arranged with respect to the periodic structure 538 and 540 such that the detection of the −1st and +1st acoustic diffraction orders 528 and 530 discriminates from the 0th order specular reflection 532.

公开(公告)号：US10067426B2

公开(公告)日：2018-09-04

申请号：US15683126

申请日：2017-08-22

Applicant: ASML Netherlands B.V.

Inventor： Nitesh Pandey

IPC: G03B27/72 ,  G03B27/42 ,  G03F7/20 ,  G01J1/04

Abstract: Metrology apparatus and methods are disclosed. In one arrangement, a metrology apparatus comprises an optical system that illuminates a structure with measurement radiation and detects the measurement radiation scattered by the structure. The optical system comprises an array of lenses that focuses the scattered measurement radiation onto a sensor. A dispersive element directs scattered measurement radiation in each of a plurality of non-overlapping wavelength bands exclusively onto a different respective lens of the array of lenses.

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：US09909983B2

公开(公告)日：2018-03-06

申请号：US15013348

申请日：2016-02-02

Applicant: ASML Netherlands B.V.

Inventor： Nitesh Pandey

IPC: G01B9/02 ,  G01N21/47 ,  G03F7/20

CPC classification number: G01N21/4788 ,  G03F7/70625 ,  G03F7/70633 ,  G03F7/70641 ,  G03F7/70941

Abstract: An optical system (10) includes an arrangement for splitting a source beam into a measurement beam and a reference beam. The reference beam is reflected off a reflective element (42) which mounted on a delay line (44). A target (35) scatters the radiation from the measurement beam. The scattered radiation and the reference beam are brought to interfere on a detector (40) by calibrating the delay line (44). The detected interference pattern is Fourier-transformed and filtered to select a region of interest around a side-band of the Fourier-transformed interference pattern in order to remove noise caused by stray radiation that hits the detector.