Abstract: A system includes an imaging system, a spatial filter, and a detector. The system is configured to receive a plurality of diffraction orders. The spatial filter is configured to block one or more undesired diffraction orders of the plurality of diffraction orders and to pass one or more desired diffraction orders of the plurality of diffraction orders. The spatial filter includes one or more obscurations having an angular dependent radius that varies azimuthally. The detector is configured to receive and measure an intensity of the one or more desired diffraction orders. The spatial filter is motorized.

Abstract: A sample inspection tool is described. The inspection tool includes a light source configured to produce effective inspection radiation below 200 nm, a sample holder, an imaging sub-system containing sub-system components that delivers light along an optical path from the light source to a sample to be held by the sample holder, and a barrier positioned between the last sub-system component in the optical path and the sample to be held by the sample holder. The barrier permits the radiation to pass therethrough while inhibiting impurities from reaching the sample to be held by the sample holder. In another embodiment, a barrier is provided for use in an inspection tool.

Abstract: Disclosed is a method of determining a value for a parameter of interest from a target on a substrate. The method comprises obtaining metrology data comprising single-wavelength parameter of interest values which were obtained using a respective different measurement wavelength; and determining said value for the parameter of interest from a stack sensitivity derived weighted combination of said single-wavelength parameter of interest values. Also disclosed is a method of selecting wavelengths for a measurement based on at least the derivative of the stack sensitivity with respect to wavelength.

Abstract: A height measurement sensor comprising projection and detection units. The projection unit comprises a radiation source and a projection grating comprising a projection grating spot having a plurality of grating lines, the projection grating arranged to receive radiation and output a radiation beam onto the surface to create a radiation spot. The detection unit comprises: a detection grating comprising a detection grating spot having a plurality of grating lines; a detector arranged to receive a reflected radiation beam comprising radiation from the radiation spot after passing through the detection grating spot; and a controller configured to (i) obtain a detector output signal comprising a plurality of periodic components; (ii) take a derivative of two points at different locations of the output signal, wherein the two points are separated by a period of the periodic components, and (iii) determine a focus plane of the sensor when the derivative changes sign.

Abstract: Disclosed is a method for determining a focus parameter from a target on a substrate. The target comprises an isofocal first sub-target and a second non-isofocal sub-target. The method comprises obtaining a first measurement signal relating to measurement of the first sub-target, a second measurement signal relating to measurement of the second sub-target and at least one trained relationship and/or model which relates at least said second measurement signal to said focus parameter. A value for said focus parameter is determined from said first measurement signal, second measurement signal and said at least one trained relationship and/or model.

Abstract: The present invention provides a fluid purging system (100) for an optical element (30), comprising a ring and a fluid supply system (40). The ring being formed of a body entirely surrounding the optical element, the ring defining a space (5) radially inwards thereof and adjacent to the optical element. The ring is formed by at least one first wall portion (10) and at least one second wall portion (20A; 20B), wherein an average height of the first wall portion is greater than an average height of the second wall portion. The fluid supply system is positioned radially outwards of the ring and configured to supply fluid to pass over the at least one second wall portion to the space.

Abstract: A droplet generator nozzle (800, 820/830) includes a metal body (802, 822), a metal fitting (812, 823/833) arranged adjacent to the metal body, and a capillary (804, 824/834) comprising a first end and a second end. The first end of the capillary is disposed within the metal fitting, and the capillary is configured to eject initial droplets of a material from the second end of the capillary. The droplet generator nozzle further includes an electromechanical element (808 828/838) disposed within the metal body and coupled to the first end of the capillary and a fastener element (810) configured to clamp around a portion of the metal body and around the metal fitting. The electromechanical element is configured to apply a change that affects droplet generation from the capillary. The second end of the capillary protrudes out from an opening in the fastener element of the droplet generator nozzle. Droplet generator nozzle 830 of FIG. 8C represents the embodiment shown in FIG.

Abstract: Disclosed is a metrology method and associated devices. The method comprises obtaining a first image, said first image being subject to one or more non-isoplanatic aberrations of an optical system used to capture said image; and non-iteratively correcting said first image for the effect of said one or more non-isoplanatic aberrations by performing one or both of: a field non-isoplanatic correction operation in field space for said first image, said field space corresponding to a field plane of the optical system; and a pupil non-isoplanatic correction operation in pupil space for said first image, said pupil space corresponding to a pupil plane of the optical system. Said one or more non-isoplanatic aberrations comprise a class of non-isoplanatic aberrations describable as a convolution combined with an object distortion and/or a pupil distortion.

Abstract: Provided is an optical element for a lithographic apparatus. The optical element includes a capping layer that includes oxygen vacancies therein. The oxygen vacancies prevent attack of the capping layer by preventing hydrogen and other species from penetrating the capping layer and underlying layers. The capping layer provides a low hydrogen recombination rate enabling hydrogen to clean the surface of the optical element. The capping layer may include an alloyed metal, a mixed metal oxide or a doped metal oxide and it may be a ruthenium capping layer that includes one or more dopants therein.

Abstract: Disclosed is a method for modeling measurement data over a substrate area and associated apparatus. The method comprises obtaining measurement data relating to a first layout; modeling a second model based on said first layout; evaluating the second model on a second layout, the second layout being more dense than said first layout; and fitting a first model to this second model according to the second layout.

Abstract: A method includes irradiating a target structure with sequential illumination shots, directing scattered beams from the target structure towards an imaging detector, generating a detection signal using the imaging detector, and determining a property of the target structure based on at least the detection signal. An integration time for each illumination shot of the sequential illumination shots is selected so to reduce a low frequency error.

Abstract: The disclosed embodiments relate to a charged particle source module for generating and emitting a charged particle beam, such as an electron beam, comprising: a frame including a first frame part, a second frame part, and one or more rigid support members which are arranged between said first frame part and said second frame part; a charged particle source arrangement for generating a charged particle beam, such as an electron beam, wherein said charged particle source arrangement, such as an electron source, is arranged at said second frame part; and a power connecting assembly arranged at said first frame part, wherein said charged particle source arrangement is electrically connected to said connecting assembly via electrical wiring.

Abstract: The present disclosure relates to apparatus and methods for assessing samples using a plurality of charged particle beams. In one arrangement, at least a subset of a beam grid of a plurality of charged particle beams and respective target portions of a sample surface are scanned relative to each other to process the target portions. Signal charged particles from the sample are detected to generate detection signals. A sample surface topographical map is generated that represents a topography of the sample surface by analyzing the detection signals.

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: A method includes treating a burled surface of an object using radiation or heat and setting parameters of the radiation or heat to effectuate a predetermined surface strength, hardness, roughness, coefficient of friction, chemical resistance, wear resistance, and/or corrosion of the burled surface.

Abstract: Systems, apparatuses, and methods are provided for measuring intensity using off-axis illumination. An example method can include illuminating a region of a surface of a substrate with a first radiation beam at a first incident angle and, in response, measuring a first set of photons diffracted from the region. The example method can further include illuminating the region with a second radiation beam at a second incident angle and, in response, measuring a second set of photons diffracted from the region. The example method can further include generating measurement data for the region based on the measured first set of photons and the measured second set of photons.

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 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: 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 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.