Abstract: A method of determining aberrations in images obtained by a charged-particle beam tool, comprising: a) obtaining two or more images of a sample, wherein each image is obtained at a known relative difference in a measurement condition of the charged-particle beam tool; b) selecting an estimated aberration parameter for the aberrations of a probe profile representing the charged-particle beam used by the charged-particle beam tool; c) evaluating an error function indicative of the difference between the two or more images and two or more estimated images that are a function of the estimated aberration parameter and the known relative difference in the measurement condition; d) updating the estimated aberration parameter; e) performing processes c) and d) iteratively; f) determining the final aberration parameter as the estimated aberration parameter that provides the smallest value of the error function.

Abstract: An inspection apparatus includes a radiation source, an optical system, and a detector. The radiation source generates a beam of radiation. The optical system directs the beam along an optical axis and toward a target so as to produce scattered radiation from the target. The optical system includes a beam displacer including four reflective surfaces having a spatial arrangement. The beam displacer receives the beam along the optical axis, performs reflections of the beam so as to displace the optical axis of the beam, rotates to shift the displaced optical axis, and preserves polarization of the beam such that a polarization state of the beam along the deflected optical axis is invariant to the rotating based on the spatial arrangement of the four reflective surfaces. The detector receives the scattered radiation to generate a measurement signal based on the received scattered radiation.

Abstract: A method of determining an overlay measurement of a substrate includes: injecting charge into a charge injection element of the substrate; determining a first capacitance of a first pair of elements and a second capacitance of a second pair of elements; and determining a capacitance ratio based on the first capacitance and the second capacitance. The overlay measurement may be determined based on the capacitance ratio, which may indicate an imbalance.

Abstract: A metrology system includes a light beam metrology apparatus configured to sense one or more aspects of an amplified light beam and to make adjustments to the amplified light beam based on the sensed one or more aspects; a target metrology apparatus configured to measure one or more properties of a modified target after a target has interacted with the amplified light beam, and to determine a moment when the modified target achieves a reference calibration state; and a control apparatus configured to: receive the reference calibration state and the moment at which the reference calibration state is achieved from the target metrology apparatus; determine a light beam calibration state of the amplified light beam based on the received reference calibration state and the moment at which the reference calibration state is achieved; and provide the light beam calibration state to the light beam metrology apparatus.

Abstract: An improved method of wafer inspection is disclosed. The improved method includes a non-transitory computer-readable medium storing a set of instructions that are executable by at least one processor of a device to cause the device to perform a method comprising: placing the wafer at a location on a stage; moving one or more movable segments of a conductive ring inward in a radial direction to enable the conductive ring to be within a predetermined distance from an edge of the wafer; and adjusting a voltage applied to the conductive ring or to a voltage applied to the wafer so that to enable the voltage applied to the conductive ring to be substantially equal to the voltage applied to the wafer to provide a substantially consistent electric field across an inner portion of the conductive ring and an outer portion of the wafer.

Abstract: An amplified optical beam is provided to a region that receives a target including target material, an interaction between the amplified optical beam and the target converting at least some of the target material from a first form to a second form to form a light-emitting plasma; first data comprising information related to the amplified optical beam is accessed; second data comprising information related to the light-emitting plasma is accessed; and an amount of the target material converted from the first form to the second form is determined. The determination is based on at least the first data and the second data, and the second form of the target material is less dense than the first form of the target material.

Abstract: A measurement mark is disclosed. According to certain embodiments, the measurement mark includes a set of first test structures developed in a first layer on a substrate, each of the set of first test structures comprising a plurality of first features made of first conducting material. The measurement mark also includes a set of second test structures developed in a second layer adjacent to the first layer, each of the set of second test structures comprising a plurality of second features made of second conducting material. The measurement mark is configured to indicate connectivity between the set of first test structures and associated second test structures in the set of second test structures when imaged using a voltage-contrast imaging method.

Abstract: Disclosed is a method of determining a characteristic of interest relating to a structure on a substrate formed by a lithographic process, the method comprising: obtaining an input image of the structure; and using a trained neural network to determine the characteristic of interest from said input image. Also disclosed is a reticle comprising a target forming feature comprising more than two sub-features each having different sensitivities to a characteristic of interest when imaged onto a substrate to form a corresponding target structure on said substrate. Related methods and apparatuses are also described.

Abstract: Disclosed is metrology apparatus for measurement of a diffractive structure on a substrate. comprising: a radiation source operable to provide first radiation for excitation of the diffractive structure, said first radiation having a first wavelength; a detection arrangement operable to detect at least diffracted second radiation comprising a second harmonic of said first radiation, said diffracted second radiation being generated from said diffractive structure and/or substrate and diffracted by said diffractive structure; and a processing arrangement operable to determine a parameter of interest relating to said diffractive structure from at least said diffracted second radiation.

Abstract: Disclosed is a method of determining a complex-valued field relating to a sample measured using an imaging system. The method comprises obtaining image data relating to a series of images of the sample, imaged at an image plane of the imaging system, and for which at least two different modulation functions are imposed in a Fourier plane of the imaging system; and determining the complex-valued field from the imaging data based on the imposed modulation functions.

Abstract: Systems and methods of enhancing imaging resolution by reducing crosstalk between detection elements of a secondary charged-particle detector in a multi-beam apparatus are disclosed. The multi-beam apparatus may comprise an electro-optical system comprising a beam-limit aperture plate having a surface substantially perpendicular to an optical axis, the beam-limit aperture plate comprising a first aperture at a first distance relative to the surface of the beam-limit aperture plate, and a second aperture at a second distance relative to the surface of the beam-limit aperture plate, the second distance being different from the first distance. The first aperture may be a part of a first set of apertures of the beam-limit aperture plate at the first distance, and the second aperture may be a part of a second set of apertures of the beam-limit aperture plate at the second distance.

Abstract: An improved system and method for inspection of a sample using a particle beam inspection apparatus, and more particularly, to systems and methods of scanning a sample with a plurality of charged particle beams. An improved method of scanning an area of a sample using N charged particle beams, wherein N is an integer greater than or equal to two, and wherein the area of the sample comprises a plurality of scan sections of N consecutive scan lines, includes moving the sample in a first direction. The method also includes scanning, with a first charged particle beam of the N charged particle beams, first scan lines of at least some scan sections of the plurality of scan sections moving towards a probe spot of the first charged particle beam. The method further includes scanning, with a second charged particle beam of the N charged particle beams, second scan lines of at least some scan sections of the plurality of scan sections moving towards a probe spot of the second charged particle beam.

Abstract: Systems and methods of profiling a charged-particle beam are disclosed. The method of profiling a charged-particle beam may comprise activating a charged-particle source to generate the charged-particle beam along a primary optical axis, modifying the charged-particle beam by adjusting an interaction between the charged-particle beam and a standing optical wave, detecting charged particles from the modified charged-particle beam after the interaction with the standing optical wave, and determining a profile of the charged-particle beam based on the detected charged particles. Alternatively, the method may include activating an optical source, modifying the optical beam by adjusting an interaction between the optical beam and a charged-particle beam, detecting an optical signal from the modified optical beam, and determining a characteristic of the charged-particle beam based on the detected optical signal.

Abstract: Systems, apparatuses, and methods for detecting a location of a positioned sample may include an electrostatic holder configured to hold a sample and form a gap area between an outside edge of the sample and a structure of the electrostatic holder when the electrostatic holder holds the sample, wherein the gap area is coated with a first coating configured to reflect a first wavelength of light with first brightness and to reflect a second wavelength of the light with second brightness, the first wavelength is within a predetermined range of wavelengths, the second wavelength is outside the predetermined range of wavelengths, and the first brightness is higher than the second brightness; a light source configured to direct the light at the gap area; and an optical detector configured to image the light reflected off the gap area.

Abstract: In some embodiments, one or more non-transitory, machine-readable medium has instructions thereon, the instructions when executed by a processor being configured to perform operations comprising obtaining scanning electron microscopy (SEM) metrology data for first areas on a training wafer, obtaining optical metrology data for second areas on the training wafer, and training a model, by using the SEM metrology data and the optical metrology data for the training wafer, to generate parameters for features on a production wafer based on optical metrology data for areas of the production wafer.

Abstract: Disclosed is a detection apparatus for simultaneous acquisition of multiple images of an object at a plurality of different focus levels; comprising: a modulator for obtaining multiple beam copies of an incoming beam; and a detector operable to capture said multiple beam copies, such that at two of said multiple beam copies are captured at different focus levels. Also disclosed is an inspection apparatus comprising such a detection system.

Abstract: Disclosed is an actuator unit for positioning an optical element including a reluctance actuator comprising a first stator part and a first mover part that are separated by a gap with respect to each other in a first direction. The first mover part is configured to move the optical element. The first stator part is configured to move the first mover part in a second direction that is different from the first direction. The first stator part comprises at least one stator pole. The first mover part comprises at least one mover pole facing the at least one stator pole. Viewed from the second direction, a width of the at least one mover pole along the second direction is smaller than a width of the at least one stator pole along the second direction.

Abstract: Disclosed is a thermo-mechanical actuator comprising a piezo-electric module, the piezo-electric module comprising at least one piezo-electric element, wherein the thermo-mechanical actuator is configured to receive a thermal actuation signal for controlling a thermal behaviour of the piezo-electric module, or provide a thermal sensing signal representative of a thermal state of the piezo-electric module. The thermo-mechanical actuator is configured to receive a mechanical actuation signal for controlling a mechanical behaviour of the piezo-electric module, or provide a mechanical sensing signal representative of a mechanical state of the piezo-electric module. And wherein the thermal actuation signal is configured to create a heat flux within the piezo-electric module and wherein the mechanical actuation signal is configured to deform the piezo-electric module.

Abstract: Embodiments herein describe methods, devices, and systems for rupture detection and end-of-life monitoring of dynamic gas lock (DGL) membranes and pupil facet mirrors in lithographic apparatuses. A method for detecting rupture of a dynamic gas lock membrane in a lithographic apparatus includes illuminating the dynamic gas lock membrane with a measurement beam using a radiation source, in which the dynamic gas lock membrane is arranged between a wafer and projection optics of the lithography apparatus, and determining whether any radiation from the measurement beam is reflected from the dynamic gas lock membrane by using reflection collection optics, in which the reflection collection optics are arranged above the dynamic gas lock membrane. A rupture in the dynamic gas lock membrane is detected if no radiation is reflected from the dynamic gas lock membrane. If radiation is reflected from the dynamic gas lock membrane, the dynamic gas lock membrane is not ruptured.

Abstract: Disclosed is an object table for holding an object, comprising: an electrostatic clamp arranged to clamp the object on the object table; a neutralizer arranged to neutralize a residual charge of the electrostatic clamp; a control unit arranged to control the neutralizer, wherein the residual charge is an electrostatic charge present on the electrostatic clamp when no voltage is applied to the electrostatic clamp.