Abstract: Disclosed herein is a computer-implemented method to improve a lithographic process for imaging a portion of a design layout onto a substrate using a lithographic projection apparatus and for transferring the imaged portion of the design layout to the substrate by an etching process, which includes the following steps: determining a value of at least one evaluation point of the lithographic process for each of a plurality of variations of the etching process; computing a multi-variable cost function of a plurality of design variables that are characteristics of the lithographic process, wherein the multi-variable cost function is a function of deviation from the determined values of the at least one evaluation point; and reconfiguring the characteristics of the lithographic process by adjusting the design variables until a termination condition is satisfied. This method may reduce the need of repeated adjustment to the lithographic process when the etching process varies.

Abstract: An actuator includes coil assemblies arranged in an array, wherein each coil assembly defines a core chamber having a core chamber height; and at least one magnetic member that extends partly along the core chamber height of the core chamber of a corresponding at least one coil assembly, wherein the at least one magnetic member is made of a magnetic material. A shape of the at least one magnetic member, a size of the at least one magnetic member, a position of the at least one magnetic member and/or the magnetic material of the at least one magnetic member may be selected so as to control one or more parameters of the actuator.

Abstract: A method including: providing a reference substrate with a first mark pattern; providing the reference substrate with a first resist layer on the reference substrate, wherein the first resist layer has a minimal radiation dose needed for development of the first resist; using a reference patterning device to impart a radiation beam with a second mark pattern in its cross-section to form a patterned radiation beam; and exposing a target portion of the first resist layer of the reference substrate n times to said patterned radiation beam to create exposed areas in the target portion of the first resist layer in accordance with the second mark pattern that have been subjected to an accumulated radiation dose above the minimal radiation dose of the first resist layer, wherein n is an integer with a value of at least two.

Abstract: Disclosed is a metrology apparatus for measuring a parameter of a lithographic process, and associated computer program and method. The metrology apparatus comprises an optical system for measuring a target on a substrate by illuminating the target with measurement radiation and detecting the measurement radiation scattered by the target; and an array of lenses. Each lens of the array is operable to focus the scattered measurement radiation onto a sensor, said array of lenses thereby forming an image on the sensor which comprises a plurality of sub-images, each sub-image being formed by a corresponding lens of the array of lenses. The resulting plenoptic image comprises image plane information from the sub-images, wavefront distortion information (from the relative positions of the sub-images) and pupil information from the relative intensities of the sub-images.

Abstract: In a method of determining an edge roughness parameter of a periodic structure, the periodic structure is illuminated (602) in an inspection apparatus. The illumination radiation beam may comprise radiation with a wavelength in the range 1 nm to 100 nm. A scattering signal (604) is obtained from a radiation beam scattered from the periodic structure. The scattering signal comprises a scattering intensity signal that is obtained by detecting an image of a far-field diffraction pattern in the inspection apparatus. An edge roughness parameter, such as Lined Edge Roughness and/or Line Width Roughness is determined (606) based on a distribution of the scattering intensity signal around a non-specular diffraction order. This may be done for example using a peak broadening model.

Abstract: A method including: obtaining a measurement of a metrology target on a substrate processed using a patterning process, the measurement having been obtained using measurement radiation; and deriving a parameter of interest of the patterning process from the measurement, wherein the parameter of interest is corrected by a stack difference parameter, the stack difference parameter representing an un-designed difference in physical configuration between adjacent periodic structures of the target or between the metrology target and another adjacent target on the substrate.

Abstract: Provided is a process of selecting a measurement location, the process including: obtaining pattern data describing a pattern to be applied to substrates in a patterning process; obtaining a process characteristic measured during or following processing of a substrate, the process characteristic characterizing the processing of the substrate; determining a simulated result of the patterning process based on the pattern data and the process characteristic; and selecting a measurement location for the substrate based on the simulated result.

Abstract: A mask assembly suitable for use in a lithographic process. The mask assembly comprises a patterning device, a sub-frame secured to the patterning device, a pellicle frame configured to support a pellicle and a mechanical attachment interface operable to allow attachment of the pellicle frame to the sub-frame and detachment of the pellicle frame from the sub-frame.

Abstract: Methods and apparatuses for estimation of at least one parameter of interest of a feature fabricated on a substrate, the feature having a plurality of structure parameters, the structure parameters including the at least one parameter of interest and one or more nuisance parameters. A receiver receives radiation scattered from one or more measured features on the substrate. A pupil generator generates an unprocessed pupil representation of the received radiation. A matrix multiplier multiplies a transformation matrix with intensities of each of a plurality of pixels of the unprocessed pupil representation to determine a post-processed pupil representation in which effects of the one or more nuisance parameters are mitigated or removed. A parameter estimator estimates the at least one parameter of interest based on the post-processed pupil representation.

Abstract: Optical element protection systems for protecting optical elements and particularly reflective optical elements from degradation of their optical properties in harsh environments such as the environment inside a vacuum chamber of an EUV light source. The systems include the uses of combinations of materials in various layers where the materials are chosen and the layers are configured and arranged to extend the lifetime of the optical element without compromising its optical properties.

Abstract: A method involving providing incident radiation of a first polarization state by an optical component into an interface of an object with an external environment, wherein a surface is provided adjacent the interface and separated by a gap from the interface, detecting, from incident radiation reflected from the interface and from the surface, radiation of a second different polarization state arising from the reflection of incident radiation of the first polarization at the interface as distinct from the radiation of the first polarization state in the reflected radiation, and producing a position signal representative of a relative position between the focus of the optical component and the object.

Abstract: An apparatus and method for cleaning a contaminated surface of a lithographic apparatus are provided. A liquid confinement structure comprises at least two openings used to supply and extract liquid to a gap below the structure. The direction of flow between the openings can be switched. Liquid may be supplied to the gap radially outward of an opening adapted for dual flow. Supply and extraction lines to respectively supply liquid to and extract liquid from the liquid confinement structure have an inner surface that is resistant to corrosion by an organic liquid. A corrosive cleaning fluid can be used to clean photo resist contamination.

Abstract: A new way of drying and/or wetting a surface, such as a top surface of a substrate, is disclosed which is useful in immersion lithography. The surface is placed under a single phase extractor and a priming liquid is delivered between the single phase extractor and the surface. The single phase extractor is only activated after the priming liquid has been provided between the single phase extractor and the surface. Priming liquid is delivered to the single phase extractor during the whole of the drying and/or wetting process.

Abstract: A measurement apparatus for measuring at least one property of an electron bunch or other group of charged particles travelling through a cavity (310), comprises a plurality of electrodes (302-308) arranged around the cavity, a plurality of optical sensors (322-328), wherein the plurality of electrodes are configured to provide signals to the optical sensors thereby to modulate at least one optical property of the optical sensors.

Abstract: There is disclosed a method of measuring a process parameter for a manufacturing process involving lithography. In a disclosed arrangement the method comprises performing first and second measurements of overlay error in a region on a substrate, and obtaining a measure of the process parameter based on the first and second measurements of overlay error. The first measurement of overlay error is designed to be more sensitive to a perturbation in the process parameter than the second measurement of overlay error by a known amount.

Abstract: Provided is a process including: obtaining a layout specifying, at least in part, a pattern to be transferred to a substrate via a patterning process and an etch process; and modifying, with one or more processors, the layout to include an etch-assist feature that is larger than a resolution limit of the patterning process and smaller than a resolution limit of the etch process, the etch-assist feature being configured to reduce a bias of the patterning process or the etch process, to reduce an etch induced shift of a feature in the layout due to the etch process, or to expand a process window of another patterning process.

Abstract: An illumination system has a microLED array 502. The microLED array 502 is imaged or placed very close to a phosphor coated glass disc 504 which upconverts the light from the microLED array into a narrow band emission. The plate has at least two different photoluminescent materials arranged to be illuminated by the microLED array and to thereby emit output light. The different photoluminescent materials have different emission spectral properties of the output light, e.g. different center wavelength and optionally different bandwidth. Illumination of different photoluminescent materials by the illumination sources is selectable, by selective activation of the microLEDs or by movement of the photoluminescent materials relative to the illumination sources, to provide different illumination of the different photoluminescent materials. This provides tunable spectral properties of the output light.

Abstract: A lithographic projection apparatus is disclosed in which a space between the projection system and a sensor is filled with a liquid.

Abstract: A method of determining a critical-dimension-related property, such as critical dimension (CD) or exposure dose, includes illuminating each of a plurality of periodic targets having different respective critical dimension biases, measuring intensity of radiation scattered by the targets, recognizing and extracting each grating from the image, determining a differential signal, and determining the CD-related property based on the differential signal, the CD biases and knowledge that the differential signal approximates to zero at a 1:1 line-to-space ratio of such periodic targets. Use of the determined CD-related property to control a lithography apparatus in lithographic processing of subsequent substrates. In order to use just two CD biases, a calibration may use measurements on a “golden wafer” (i.e. a reference substrate) to determine the intensity gradient for each of the CD pairs, with known CDs. Alternatively, the calibration can be based upon simulation of the sensitivity of intensity gradient to CD.

Abstract: A membrane for EUV lithography, the membrane having a thickness of no more than 200 nm and including a stack having: at least one silicon layer; and at least one silicon compound layer made of a compound of silicon and an element selected from the group consisting of boron, phosphorous, bromine.