Abstract: An immersion liquid is provided comprising an ion-forming component, e.g. an acid or a base, which has a relatively high vapor pressure. Also provided are lithography processes and lithography systems using the immersion liquid.

Abstract: A method of manufacturing a multi-layer mirror comprising a multi-layer stack of pairs of alternating layers of a first material and silicon, the method comprising depositing a stack of pairs of alternating layers of the first material and layers of silicon, the stack being supported by a substrate and doping at least a first layer of the first material with a dopant material.

Abstract: A reconstruction process includes measuring structures formed on a substrate by a lithographic process, determining a reconstruction model for generating modeled patterns, computing and minimizing a multi-variable cost function including model errors. Errors induced by nuisance parameters are modeled based on statistical description of the nuisance parameters' behavior, described by probability density functions. From the statistical description model errors are calculated expressed in terms of average model errors and weighing matrices. These are used to modify the cost function so as to reduce the influence of the nuisance parameters in the reconstruction, without increasing the complexity of the reconstruction model. The nuisance parameters may be parameters of the modeled structure, and/or parameters of an inspection apparatus used in the reconstruction.

Abstract: An apparatus and method are used to form patterns on a substrate. The apparatus comprises a projection system, a patterning device, a low-pass filter, and a data manipulation device. The projection system projects a beam of radiation onto the substrate as an array of sub-beams. The patterning device modulates the sub-beams to substantially produce a requested dose pattern on the substrate. The low-pass filter operates on pattern data derived from the requested dose pattern in order to form a frequency-clipped target dose pattern that comprises only spatial frequency components below a selected threshold frequency. The data manipulation device produces a control signal comprising spot exposure intensities to be produced by the patterning device, based on a direct algebraic least-squares fit of the spot exposure intensities to the frequency-clipped target dose pattern. In various examples, filters can also be used.

Abstract: In an inspection apparatus, a target on the surface is illuminated with illuminating radiation that comprises first and second illuminating components. The illuminating components form one or more periodic illuminating patterns on the surface. A plurality of scattered radiation patterns formed by the illuminating radiation after scattering by the target is captured at a detector for a number of values of a controllable characteristic of at least one of the illuminating components. The captured radiation is then used to reconstruct data describing the target.

Abstract: A patterning device support for controlling a temperature of a patterning device can include a movable component. The movable component can include a gas inlet for supplying a gas flow across a surface of the patterning device and a gas outlet for extracting the gas flow. The patterning device support can also include a gas flow generator coupled to a duct, for recirculating the gas flow from the gas outlet to the gas inlet.

Abstract: A gas knife configured to dry a surface in an immersion lithographic apparatus is optimized to remove liquid by ensuring that a pressure gradient is built up in the liquid film on the surface being dried.

Abstract: A method of calculating electromagnetic scattering properties of a structure, the structure including materials of differing properties and the structure being periodic in at least one lateral direction and extending in a vertical direction, comprises: numerically solving a volume integral equation for electromagnetic scattering for a plurality of modes in the at least one lateral direction, by performing, for each respective mode, integration (1350) of a pseudo-spectral polynomial (Chebyshev) expansion in the vertical direction multiplied by a ID Green's function using the same sample points in the orthogonal direction for all of the plurality of modes. The integration is performed by solving a regularized linear system of equations between first (1116) and second (1120) discrete transformation steps to compute (1118) values of a regularized Chebyshev expansion coefficient vector (?). Electromagnetic scattering properties of the structure are calculated using the results of the numerical solution.

Abstract: A positioning apparatus includes a first object and a second object; a positioning system configured to position the first and the second objects with respect to each other; and a flexible transportation line that is connected to the first and the second objects, the flexible transportation line having a stiffness that varies along the flexible transportation line such that the flexible transportation line can be represented by a dynamic transfer function, the dynamic transfer function being adapted to a closed-loop transfer function of the positioning system.

Abstract: Disclosed herein is a computer-implemented method of image simulation for a device manufacturing process, the method comprising: identifying regions of uniform optical properties from a portion or an entirety of a substrate or a patterning device, wherein optical properties are uniform within each of the regions; obtaining an image for each of the regions, wherein the image is one that would be formed from the substrate if the entirety of the substrate or the patterning device has the same uniform optical properties as that region; forming a stitched image by stitching the image for each of the regions according to locations of the regions in the portion or the entirety of the substrate of the patterning device; forming an adjusted image by applying adjustment to the stitched image for at least partially correcting for or at least partially imitating an effect of finite sizes of the regions.

Abstract: A photocathode comprises a substrate in which a cavity is formed and a film of material disposed on the substrate. The film of material comprises an electron emitting surface configured to emit electrons when illuminated by a beam of radiation. The electron emitting surface is on an opposite side of the film of material from the cavity.

Abstract: Disclosed is a method of obtaining data describing an object structure. The method comprising the steps of: (a) illuminating the object structure with illuminating radiation; (b) modulating the phase of the illuminating radiation after scattering by the object structure, the modulation comprising applying a first phase factor dependent upon at least one controllable parameter and an aberration function having a form of a subadditive function of a vector norm; (c) capturing a plurality of intensity patterns, wherein each intensity pattern corresponds to a unique value of the at least one controllable parameter; and (d) reconstructing the data describing the object structure based on the plurality of intensity patterns. Also disclosed are corresponding inspection and lithographic apparatuses, a method of manufacturing devices and a computer program.

Abstract: A method of correcting aberrations caused by a projection system of a lithographic apparatus, the method including performing a measurement of an aberration caused by the projection system using a sensor located in the lithographic apparatus, determining, based on a history of operation of the lithographic apparatus since a change of machine state, whether to average the measured aberration with one or more aberration measurements previously obtained using the sensor, calculating a correction to be applied to the lithographic apparatus using the measured aberration if it is determined that averaging should not be performed, calculating a correction to be applied to the lithographic apparatus using an averaged aberration measurement if it is determined that averaging should be performed, and applying the calculated correction to the lithographic apparatus.

Abstract: A pump includes a collecting duct to guide a two-phase fluid provided with magnetic field responsive particles, a collecting duct magnet system arranged along the collecting duct and configured to generate a magnetic field in at least a part of the collecting duct, a pumping duct to guide the two-phase fluid, a pumping duct inlet being connected to a collecting duct outlet, and a pumping duct magnet system arranged along the pumping duct and configured to generate a magnetic field in at least a part of the pumping duct. A pump driver is configured to drive the collecting duct magnet system to generate a spatial repetition of collecting duct magnetic fields moving along a length of the collecting duct, and is configured to drive the pumping duct magnet system to generate a spatial repetition of pumping duct magnetic fields moving along a length of the pumping duct.

Abstract: A lithographic apparatus including: a projection system to project radiation onto a substrate supported on a substrate stage, during an exposure phase; a sensing system to sense a property of the substrate on the stage during a sensing phase; and a positioning system to determine a position of the stage relative to a reference system via a radiation path between the stage and the reference system, wherein the apparatus is configured to control stage movement relative to the reference system in the sensing phase and to control other movement relative to the reference system during the exposure phase; the stage or reference system having an outlet to provide a gas curtain to reduce ingress of ambient gas into the path; and the apparatus is operative such that a characteristic of the gas curtain is different in at least part of the sensing phase compared to in the exposure phase.

Abstract: Online calibration of laser performance as a function of the repetition rate at which the laser is operated is disclosed. The calibration can be periodic and carried out during a scheduled during a non-exposure period. Various criteria can be used to automatically select the repetition rates that result in reliable in-spec performance. The reliable values of repetition rates are then made available to the scanner as allowed values and the laser/scanner system is then permitted to use those allowed repetition rates.

Abstract: Methods and inspection apparatus and computer program products for assessing a quality of reconstruction of a value of a parameter of interest of a structure, which may be applied for example in metrology of microscopic structures. It is important the reconstruction provides a value of a parameter of interest (e.g. a CD) of the structure which is accurate as the reconstructed value is used to monitor and/or control a lithographic process. This is a way of assessing a quality of reconstruction (803) of a value of a parameter of interest of a structure which does not require the use of a scanning electron microscope, by predicting (804) values of the parameter of interest of structures using reconstructed values of parameters of structures, and by comparing (805) the predicted values of the parameter of interest and the reconstructed values of the parameter of interest.

Abstract: Disclosed is an illumination system for a metrology apparatus and a metrology apparatus comprising such an illumination system. The illumination system comprises an illumination source; and a linear variable filter arrangement configured to filter a radiation beam from said illumination source and comprising one or more linear variable filters. The illumination system is operable to enable selective control of a wavelength characteristic of the radiation beam subsequent to it being filtered by the linear variable filter arrangement.

Abstract: A method of determining a parameter of a patterning process, the method including: obtaining a detected representation of radiation redirected by a structure having geometric symmetry at a nominal physical configuration, wherein the detected representation of the radiation was obtained by illuminating a substrate with a radiation beam such that a beam spot on the substrate was filled with the structure; and determining, by a hardware computer system, a value of the patterning process parameter based on optical characteristic values from an asymmetric optical characteristic distribution portion of the detected radiation representation with higher weight than another portion of the detected radiation representation, the asymmetric optical characteristic distribution arising from a different physical configuration of the structure than the nominal physical configuration.

Abstract: A metrology target includes: a first structure arranged to be created by a first patterning process; and a second structure arranged to be created by a second patterning process, wherein the first structure and/or second structure is not used to create a functional aspect of a device pattern, and wherein the first and second structures together form one or more instances of a unit cell, the unit cell having geometric symmetry at a nominal physical configuration and wherein the unit cell has a feature that causes, at a different physical configuration than the nominal physical configuration due to a relative shift in pattern placement in the first patterning process, the second patterning process and/or another patterning process, an asymmetry in the unit cell.