Abstract: Disclosed is a method for determining a parameter of interest relating to at least one target on a substrate. The method comprises obtaining metrology data comprising at least one asymmetry signal, said at least one asymmetry signal comprising a difference or imbalance in a measurement parameter from the target; obtaining a trained model having been trained or configured to relate said at least one asymmetry signal to the parameter of interest, the trained model comprising at least one proxy for at least one nuisance component of the at least one asymmetry signal; and inferring said parameter of interest for said at least one target from said at least one asymmetry signal using the trained model.

Abstract: Disclosed herein is an multi-array lens configured in use to focus a plurality of beamlets of charged particles along a multi-beam path, wherein each lens in the array comprises: an entrance electrode; a focussing electrode and a support. The focusing electrode is down beam of the entrance electrode along a beamlet path and is configured to be at a potential different from the entrance electrode. The support is configured to support the focusing electrode relative to the entrance electrode. The focusing electrode and support are configured so that in operation the lens generates a rotationally symmetrical field around the beamlet path.

Abstract: A micromirror array comprises a substrate, a plurality of minors for reflecting incident light and, for each mirror (20) of the plurality of minors, at least one piezoelectric actuator (21) for displacing the minor, wherein the at least one piezoelectric actuator is connected to the substrate. The micromirror array further comprises one or more pillars (24) connecting the minor to the at least one piezoelectric actuator. Also disclosed is a method of forming such a micromirror array. The micromirror array may be used in a programmable illuminator. The programmable illuminator may be used in a lithographic apparatus and/or in an inspection apparatus.

Abstract: A method for calculating a spatial map associated with a component, the spatial map indicating spatial variations of thermal expansion parameters in the component, the method comprising: providing or determining a temperature distribution in the component as a function of time; calculating the spatial map associated with the component using the provided or determined temperature distribution in the component and optical measurements of a radiation beam that has interacted directly or indirectly with the component, the optical measurements being time synchronized with the provided or determined temperature distribution in the component.

Abstract: Disclosed is a substrate and associated patterning device. The substrate comprises at least one target arrangement suitable for metrology of a lithographic process, the target arrangement comprising at least one pair of similar target regions which are arranged such that the target arrangement is, or at least the target regions for measurement in a single direction together are, centrosymmetric. A metrology method is also disclosed for measuring the substrate. A metrology method is also disclosed comprising which comprises measuring such a target arrangement and determining a value for a parameter of interest from the scattered radiation, while correcting for distortion of the metrology apparatus used.

Abstract: A multi-beam inspection apparatus including an adjustable beam separator is disclosed. The adjustable beam separator is configured to change a path of a secondary particle beam. The adjustable beam separator comprises a first Wien filter and a second Wien filter. Both Wien filters are aligned with a primary optical axis. The first Wien filter and the second Wien filter are independently controllable via a first excitation input and a second excitation input, respectively. The adjustable beam separator is configured move the effective bending point of the adjustable beam separator along the primary optical axis based on the first excitation input and the second excitation input.

Abstract: An assessment method comprising: using an assessment apparatus to generate assessment signals representing a property of a surface of a sample; processing the assessment signals to identify candidate defects and outputting a candidate defect signal; monitoring the status of the assessment apparatus for error conditions and generating a status signal indicating any error conditions during functioning of the assessment apparatus; and analysing the candidate defect signal to determine if the candidate defects are real defects; wherein analysis of a candidate defect is not completed if the status signal indicates that the assessment signal(s) and/or the candidate defect signal corresponding to the candidate defect would have been affected by an error condition.

Abstract: An optical apparatus for a reticle stage of a lithographic apparatus is disclosed. The optical apparatus comprises: a reflective optical element comprising a surface for exposure to radiation; at least two electrodes located at the surface; and a measurement system configured to measure one or more electrical characteristics of the reflective optical element between the at least two electrodes. Also disclosed is a method of measuring a degradation of a reflective optical element having a surface for exposure to radiation in a lithographic apparatus, the method comprising: providing at least two electrodes at the surface of the reflective optical element; and measuring one or more electrical characteristics of the reflective optical element between the at least two electrodes.

Abstract: A controller system is configured to control a plant and comprising a feedforward controller to provide, based on a reference state signal, a feedforward signal to the plant, and a feedback controller system to provide a feedback signal to the plant, based on a difference between the reference state signal and a plant state signal representing an actual state of the plant. The feedback controller system comprises an integrator, a trajectory generator, and a selector. The feedback controller system is configured to operate as a function of the reference state in a first control mode or a second control mode, wherein the feedback controller system, in the first control mode, operates the selector to select the trajectory generator output signal generated by the trajectory generator, and wherein the feedback controller system, in the second control mode, operates the selector to select the integrator output signal generated by the integrator.

Abstract: The present disclosure relates to apparatus and methods for assessing samples using charged particles. In one arrangement, a degassing action is performed by exposing a target area of a sample with charged particles to stimulate degassing. A rate of degassing from the target area is measured during the degassing action. Initiation of an assessing of the sample is controlled based on a characteristic of the measured rate of degassing. The assessing of the sample comprising exposing the target area with charged particles and detecting signal charged particles from the target area.

Abstract: A target delivery system for an extreme ultraviolet (EUV) light source is disclosed. The system includes: a conduit including an orifice configured to fluidly couple to a reservoir; an actuator configured to mechanically couple to the conduit such that motion of the actuator is transferred to the conduit; and a control system coupled to the actuator, the control system being configured to: determine an indication of pressure applied to target material in the reservoir, and control the motion of the actuator based on the determined indication of applied pressure. Moreover, techniques for operating a supply system are disclosed. For example, one or more characteristics of the supply system are determined, and an actuator that is mechanically coupled to the supply system is controlled based on the one or more determined characteristics such that an orifice of the supply system remains substantially free of material damage during operational use.

Abstract: Disclosed is a pupil shaping arrangement for obtaining a defined pupil intensity profile for a metrology illumination beam configured for use in a metrology application. The pupil shaping arrangement comprises an engineered diffuser (ED) having a defined far-field profile configured to impose said defined pupil intensity profile on said metrology illumination beam. The pupil shaping arrangement may further comprise a multimode fiber (MMF) and be configured to reduce spatial coherence of coherent radiation.

Abstract: Systems and methods for training a machine learning model for defect detection include obtaining training data including an inspection image of a fabricated integrated circuit (IC) and design layout data of the IC, and training a machine learning model using the training data. The machine learning model includes a first autoencoder and a second autoencoder. The first autoencoder includes a first encoder and a first decoder. The second autoencoder includes a second encoder and a second decoder. The second decoder is configured to obtain a first code outputted by the first encoder. The first decoder is configured to obtain a second code outputted by the second encoder.

Abstract: A method of training a generator model comprising: using the generator model to generate the predictive data based on the first measured data, wherein the first measured data and the predictive data can be used to form images of the sample; pairing subsets of the first measured data with subsets of the predictive data, the subsets corresponding to locations within the images of the sample that can be formed from the first measured data and the predictive data; using a discriminator to evaluate a likelihood that the predictive data comes from a same data distribution as second measured data measured from a sample after an etching process; and training the generator model based on: correlation for the pairs corresponding to a same location relative to correlation for pairs corresponding to different locations, the correlation being the correlation between the paired subsets of data, and the likelihood evaluated by the discriminator.

Abstract: A method for processing images for metrology using a charged particle beam tool may include obtaining, from the charged particle beam tool, an image of a portion of a sample. The method may further include processing the image using a first image processing module to generate a processed image. The method may further include determining image quality characteristics of the processed image and determining whether the image quality characteristics of the processed image satisfy predetermined imaging criteria. The method may further include in response to the image quality characteristics of the processed image not satisfying the imaging criteria, updating a tuning condition of the charged-particle beam tool, acquiring an image of the portion of the sample using the charged-particle beam tool that has the updated tuning condition, and processing the acquired image using the first image processing module to enable the processed acquired image to satisfy the predetermined imaging criteria.

Abstract: A method for determining an optimized weighting of an encoder and decoder network; the method comprising: for each of a plurality of test weightings, performing the following steps with the encoder and decoder operating using the test weighting: (a) encoding, using the encoder, a reference image and a distorted image into a latent space to form an encoding; (b) decoding the encoding, using the decoder, to form a distortion map indicative of a difference between the reference image and a distorted image; (c) spatially transforming the distorted image by the distortion map to obtain an aligned image; (d) comparing the aligned image to the reference image to obtain a similarity metric; and (e) determining a loss function which is at least partially defined by the similarity metric; wherein the optimized weighting is determined to be the test weighting which has an optimized loss function.

Abstract: The embodiments of the present disclosure provide a method of processing data derived from a sample, comprising processing an initial data set of elements derived from a detection by a detector for calibration, the data set comprising elements representing nuisance signals and detection signals. The processing of the initial data set comprising: fitting a distribution model to the initial data set to create a nuisance distribution model; setting a signal strength value, and selecting elements in the initial data set having a magnitude greater than the signal strength value as a set of defect candidates; fitting a distribution model to the set of defect candidates to create a defect distribution model of detection signals; and determining a signal strength threshold dependent on at least the defect distribution model. The determining comprising correcting the defect distribution model.

Abstract: An improved systems and methods for generating a denoised inspection image are disclosed. An improved method for generating a denoised inspection image comprises acquiring an inspection image; generating a first denoised image by executing a first type denoising algorithm on the inspection image; and generating a second denoised image by executing a second type denoising algorithm on the first denoised image.

Abstract: A charged particle-optical device for projecting a plurality of charged particle beams along respective beam paths towards a sample location, the charged particle-optical device comprising: a charged particle-optical assembly configured to manipulate the charged particle beams, the charged particle-optical assembly comprising a first charged particle-optical element comprising a plate having one or more apertures around a beam path of the charged particle beams; and an electrical connector configured to electrically connect the plate of the first charged particle-optical element to an electrical power source, wherein the electrical connector: comprises a shield configured to define a field free region substantially free of electric fields; and is configured to be electrically connectable to a flexible coupling configured to electrically connect the plate of the first charged particle-optical element to the electrical power source, the flexible coupling located within the field free region.

Abstract: Systems and methods for image enhancement are disclosed. A method for enhancing an image may include acquiring a scanning electron microscopy (SEM) image. The method may also include simulating diffused charge associated with a position of the SEM image. The method may further include providing an enhanced SEM image based on the SEM image and the diffused charge.