Abstract: A reticle conditioning system includes: a support structure to support a reticle; a gas supply module to provide a flow of gas adjacent to the reticle; and a biasing module to control an electrical potential of the reticle. The biasing module includes a first electrode, a second electrode and a voltage supply. The first and second electrodes are each spaced apart from and facing the reticle, when the reticle is supported by the support structure, so as to at least partially overlap with the reticle. The voltage supply is arranged to maintain the first electrode at a positive voltage, and the second electrode at a negative voltage, these voltages being such that the voltage of the reticle is negative. The second electrode is disposed such that, when the reticle is supported by the support structure, it does not overlap an image forming portion of the reticle.

Abstract: A method for generating a mask pattern to be employed in a patterning process. The method including obtaining (i) a first feature patch including a first polygon portion of an initial mask pattern, and (ii) a second feature patch including a second polygon portion of the initial mask pattern; adjusting the second polygon portion at a patch boundary between the first feature patch and the second feature patch such that a difference between the first polygon portion and the second polygon portion at the patch boundary is reduced; and combining the first polygon portion and the adjusted second polygon portion at the patch boundary to form the mask pattern.

Abstract: A method for measuring a parameter of interest from a target and associated apparatuses. The method includes obtaining measurement acquisition data relating to measurement of the target and finite-size effect correction data and/or a trained model operable to correct for at least finite-size effects in the measurement acquisition data. At least finite-size effects in the measurement acquisition data is corrected for using the finite-size effect correction data and/or the trained model to obtain corrected measurement data and/or obtain a parameter of interest; and where the correcting does not directly determine the parameter of interest, determining the parameter of interest from the corrected measurement data.

Abstract: A detector may be provided for a charged particle apparatus comprising: a sensing element including a diode; and a circuit configured to detect an electron event caused by an electron impacting the sensing element, wherein the circuit comprises a voltage monitoring device and a reset device, wherein the reset device is configured to regularly reset the diode by setting a voltage across the diode to a predetermined value, and wherein the voltage monitoring device is connected to the diode to monitor a voltage across the diode in between resets.

Abstract: The system includes a radiation source, a diffractive element, an optical system, a detector, and a processor. The radiation source generates radiation. The diffractive element diffracts the radiation to generate a first beam and a second beam. The first beam includes a first non-zero diffraction order and the second beam includes a second non-zero diffraction order that is different from the first non-zero diffraction order. The optical system receives a first scattered beam and a second scattered radiation beam from a target structure and directs the first scattered beam and the second scattered beam towards a detector. The detector generates a detection signal. The processor analyzes the detection signal to determine a target structure property based on at least the detection signal. The first beam is attenuated with respect to the second beam or the first scattered beam is purposely attenuated with respect to the second scattered beam.

Abstract: A reticle transport system having a magnetically levitated transportation stage is disclosed. Such a system may be suitable for use in vacuum environments, for example, ultra-clean vacuum environments.

Abstract: The disclosed embodiments provide a various techniques for detecting secondary charged particles and backscatter charged particles, including accelerating charged particle sub-beams along sub-beam paths to a sample, repelling secondary charged particles from detector arrays, using mirror detector arrays, using multiple detector arrays, and providing devices and detectors which can switch between modes for primarily detecting charged particles and modes for primarily detecting secondary particles.

Abstract: The present disclosure provides a charged particle optical device for a charged particle system. The device projects an array of charged particle beams towards a sample. The device comprises a control lens array to control a parameter of the array of beams; and an objective lens array to project the array of beams onto the sample, the objective lens array being down beam of the control lens. The objective lens array comprises: an upper electrode; and a lower electrode arrangement that comprises an up-beam electrode and a down-beam electrode. The device is configured to apply an upper potential to the upper electrode, an up-beam potential to the up-beam electrode and a down-beam potential to the down-beam electrode. The potentials are controlled to control the landing energy of the beams on the sample and. to maintain focus of the beams on the sample at the landing energies.

Abstract: An extreme ultraviolet radiation (EUV) source, including: a vessel having an inner vessel wall and an intermediate focus (IF) region; an EUV collector disposed inside the vessel, the EUV collector including a reflective surface configured to reflect EUV radiation toward the intermediate focus region, the reflective surface configured to directionally face the IF region of the vessel; a showerhead disposed along at least a portion of the inner vessel wall, the showerhead including a plurality of nozzles configured to introduce gas into the vessel; and one or more exhausts configured to remove gas introduced into the vessel, the one or more exhausts being oriented along at least a portion of the inner vessel wall so that the gas is caused to flow away from the EUV collector.

Abstract: A data processing device for detecting defects in sample images generated by a charged particle assessment system, the device comprising: an input module, a filter module, a reference image module and a comparator. The input module is configured to receive a sample image from the charged particle assessment system. The filter module is configured to apply a filter to the sample image to generate a filtered sample image. The reference image module is configured to provide a reference image based on one or more source images. The comparator is configured to compare the filtered sample image to the reference image so as to detect defects in the sample image.

Abstract: A metrology apparatus for determining one or more parameters of a structure fabricated in or on a semiconductor substrate. The apparatus comprises a transducer array comprising a plurality of transducers positioned in a plane. The plurality of transducers comprises at least one transmitter transducer for emitting acoustic radiation in a frequency range from 1 GHz to 100 GHz towards the structure, and at least one receiver transducer for receiving acoustic radiation reflected and/or diffracted from the structure.

Abstract: A sensor is disclosed, wherein a transducer generates acoustic waves, which are received by a lens assembly. The lens assembly transmits and directs at least a part of the acoustic waves to a target. The lens assembly then receives at least a part of acoustic waves, after interaction with the target. The sensor further comprises an optical detector that comprises at least one optically reflective member located at a surface of the lens assembly, which surface is arranged opposite to a surface of the lens assembly which faces a focal plane of the lens assembly, wherein the at least one optically reflective member is mechanically displaced in response to the acoustic waves, which are received and transmitted by the lens assembly.

Abstract: Disclosed is a substrate, associated patterning device and a method for measuring a position of the substrate. The method comprises performing an alignment scan of an alignment mark to obtain simultaneously: a first measurement signal detected in a first measurement channel and a second measurement signal detected in a second measurement channel. The first and second measurement signals are processed by subtracting a first direction component of the first measurement signal from a first direction component of the second measurement signal to obtain a first processed signal, the first direction components relating to said first direction. The position of an alignment mark is determined with respect to the first direction from the first processed signal.

Abstract: Systems and methods for implementing charged particle flooding in a charged particle beam apparatus are disclosed. According to certain embodiments, a charged particle beam system includes a charged particle source and a controller which controls the charged particle beam system to emit a charged particle beam in a first mode where the beam is defocused and a second mode where the beam is focused on a surface of a sample.

Abstract: A method of detecting charged particles may include detecting beam intensity as a primary charged particle beam moves along a first direction; acquiring a secondary beam spot projection pattern as the primary charged particle beam moves along a second direction; and determining a parameter of a secondary beam spot based on the acquired secondary beam spot projection pattern. A method of compensating for beam spot changes on a detector may include acquiring a beam spot projection pattern on the detector, determining a change of the beam spot projection pattern, and adjusting a parameter of a detector cell of the detector based on the change. Another method may be provided for forming virtual apertures with respect to detector cells of a detector.

Abstract: Assessment systems and methods are disclosed. In one arrangement, charged particles are directed in sub-beams arranged in a multi-beam towards a sample. A plurality of control electrodes define a control lens array. Each control lens in the control lens array is aligned with a sub-beam path of a respective sub-beam of the multi-beam and configured to operate on the respective sub-beam. A plurality of objective electrodes define an objective lens array that directs the sub-beams onto a sample. Objective lenses are aligned with a sub-beam path aligned with a respective control lens. Selectable landing energies are implemented for a sub-beam of the multi-beam by applying corresponding potentials to the control electrodes and the objective electrodes. A controller is configured to select corresponding potentials so a spatial relationship between an image plane of the system and all control electrodes and objective electrodes is the same for each selectable landing energy.

Abstract: Systems, apparatuses, and methods are provided for heating a plurality of optical components. An example method can include receiving an input radiation beam from a radiation source. The example method can further include generating a plurality of output radiation beams based on the input radiation beam. The example method can further include transmitting the plurality of output radiation beams towards a plurality of heater head optics configured to heat the plurality of optical components. Optionally, the example method can further include controlling a respective power value, and realizing a flat-top far-field profile, of each of the plurality of output radiation beams.

Abstract: A method of predicting thermally induced aberrations of a projection system for projecting a radiation beam, the method comprising: calculating an irradiance profile for at least one optical element of the projection system from a power and illumination source pupil of the radiation beam, estimating a temperature distribution as a function of time in the at least one optical element of the projection system using the calculated irradiance profile for the at least one optical element of the projection system; calculating the thermally induced aberrations of the projection system based on the estimated temperature distribution and a thermal expansion parameter map associated with the at least one optical element of the projection system, wherein the thermal expansion parameter map is a spatial map indicating spatial variations of thermal expansion parameters in the at least one optical element of the projection system or a uniform map.

Abstract: The embodiments of the present disclosure provide a charged particle assessment system comprising: a sample holder configured to hold a sample having a surface; a charged particle-optical device configured to project a charged particle beam towards the sample, the charged particle beam having a field of view corresponding to a portion of the surface of the sample, the charged particle-optical device having a facing surface facing the sample holder; and a projection assembly arranged to direct a light beam along a light path such that the light beam reflects off the facing surface up-beam, with respect to the light path, of being incident on the portion of the surface of the sample.

Abstract: There is provided a charged particle apparatus comprising: a particle beam generator, optics, a first and a second positioning device, both configured for positioning the substrate relative to the particle beam generator along its optical axis, and a controller configured for switching between a first operational mode and a second operational mode. The apparatus is configured, when operating in the first operational mode, for irradiating the substrate by the particle beam at a first landing energy of the particle beam and, when operating in the second operational mode, for irradiating the substrate at a second, different landing energy. When operating in the first operational mode, the second positioning device is configured to position the substrate relative to the particle beam generator at a first focus position of the particle beam and in the second operational mode, to position the substrate at a second, different focus position.