Abstract: Methods and apparatus are provided for promoting the coalescence of fuel droplets in a stream generated by a radiation source droplet stream generator for use in lithographic apparatus. Various examples are described in which a modulating voltage source is applied to the emitter so that the electrical characteristics of the droplets may be controlled. This results in acceleration and deceleration of droplets in the stream which causes them to merge and promotes coalescence.

Abstract: In an embodiment, a lithography method is disclosed that includes providing a providing a first heat load to a first area of an object, and providing a second heat load to a second area of the object, wherein the second heat load is configured to ensure a deformation of the first area of the object caused by providing both the first heat load and the second heat load is smaller than a deformation of the first area of the object caused by providing only the first heat load.

Abstract: A substrate is provided with device structures and metrology structures (800). The device structures include materials exhibiting inelastic scattering of excitation radiation of one or more wavelengths. The device structures include structures small enough in one or more dimensions that the characteristics of the inelastic scattering are influenced significantly by quantum confinement. The metrology structures (800) include device-like structures (800b) similar in composition and dimensions to the device features, and calibration structures (800a). The calibration structures are similar to the device features in composition but different in at least one dimension. Using an inspection apparatus and method implementing Raman spectroscopy, the dimensions of the device-like structures can be measured by comparing spectral features of radiation scattered inelastically from the device-like structure and the calibration structure.

Abstract: An inspection apparatus (300) includes a focus monitoring arrangement (500, 500?). Focusing radiation (505) comprises radiation having a first wavelength and radiation having a second wavelength. Reference radiation and focusing radiation at each wavelength are provided with at least one relative frequency shift so that the interfering radiation detected in the detection system includes a time-varying component having a characteristic frequency. A focus detection system (520) comprises one or more lock-in detectors (520b, 520c, 900). Operating the lock-in detectors with reference to both the first and second characteristic frequencies allows the arrangement to select which of the first and second focusing radiation is used to determine whether the optical system is in focus. Good quality signals can be obtained from targets of different structure.

Abstract: Ghost reflections in a catadioptric scatterometer objective are excluded from an angle-resolved spectrum measurement by using a partial pupil for illumination and for the measurement excluding the area of the pupil plane that has been illuminated. Ghost reflections are reflected back into same point in the pupil plane. The ghost reflections do not interfere with the signal in the non-illuminated area of the pupil plane. An illumination system provides a beam of electromagnetic radiation to illuminate a first area in an illumination pupil plane of the objective. The objective is arranged as to illuminate the substrate with the beam of electromagnetic radiation. The illumination pupil plane is the back projected image of the pupil plane of the objective and is also imaged into the measurement pupil plane at the back focal plane of the objective, via auxiliary optics.

Abstract: An apparatus measures positions of marks on a lithographic substrate. A measurement optical system comprises illumination subsystem for illuminating the mark with a spot of radiation and a detecting subsystem for detecting radiation diffracted by the mark. A tilting mirror moves the spot of radiation relative to the reference frame of the measurement optical system synchronously with a scanning motion of the mark itself, to allow more time for accurate position measurements to be acquired. The mirror tilt axis is arranged along the intersection of the mirror plane with a pupil plane of the objective lens to minimize artifacts of the scanning. The same geometrical arrangement can be used for scanning in other types of apparatus, for example a confocal microscope.

Abstract: A discharge produced plasma radiation source includes a laser beam pulse generator configured to provide a laser beam pulse to trigger a pinch in a plasma of the discharge produced plasma radiation source. The laser beam pulse generator is arranged to provide a laser beam pulse having an energy greater than an optimum laser beam pulse energy that corresponds to a maximum output of a given wavelength of radiation for a given discharge energy.

Abstract: A radiation spot measurement system for a lithographic apparatus, the system having a target onto which a radiation system of the lithographic apparatus may project spots of radiation for a measurement process, the target having a measurement target. The system further includes a radiation detector to detect radiation from one of the spots, and a controller to receive information from the radiation detector and to determine the position of the spot of radiation relative to an intended position of the spot of radiation.

Abstract: A method of patterning substrates using a lithographic apparatus. The method comprising providing a beam of radiation using an illumination system, using a patterning device to impart the radiation beam with a pattern in its cross-section, and using a projection system to project the patterned radiation beam onto target portions of a lot of substrates, wherein the method further comprises performing a radiation beam aberration measurement after projecting the patterned radiation beam onto a subset of the lot of substrates, performing an adjustment of the projection system using the results of the radiation beam aberration measurement, then projecting the patterned radiation beam onto a further subset of the lot of substrates.

Abstract: An arrangement actuates an element in a microlithographic projection exposure apparatus. The arrangement includes first and second actuators and first and second mechanical couplings. The first and second actuators are coupled to the element via corresponding ones of the first and second mechanical couplings for applying respective forces to the element which is regulatable in at least one degree of freedom. The first and second actuators have first and second actuator masses, respectively, and the first actuator mass and the first mechanical coupling conjointly define a first mass-spring system operating as a first low-pass filter. The second actuator mass and the second mechanical coupling conjointly define a second mass-spring system operating as a second low-pass filter. The first and second mass-spring systems have first and second natural frequencies deviating from each other by a maximum deviation equal to 10% of the largest of the first and second natural frequencies.

Abstract: An inspection apparatus comprises an illumination system (12) for illuminating a target structure with illuminating radiation and a collection system for collecting the illuminating radiation after it has been scattered by the target structure. A programmable spatial light modulator (713) comprises an array of movable mirror elements (742) in a conjugate pupil plane (P?) of the illumination system. Between the array of mirror elements and the target a common optical path is defined forming part of the illumination system and the collection system. Each mirror element is movable between a first position where it reflects illuminating radiation into the common optical path and a second position where it reflects radiation from the common optical path toward a detector (19, 23). Various combinations of illumination aperture and collection aperture can be defined without the light losses associated with beam splitters and transmissive spatial light modulators.

Abstract: A substrate holder for use in a lithographic apparatus. The substrate holder comprises a main body, a plurality of burls and a heater and/or a temperature sensor. The main body has a surface. The plurality of burls project from the surface and have end surfaces to support a substrate. The heater and/or temperature sensor is provided on the main body surface. The substrate holder is configured such that when a substrate is supported on the end surfaces, a thermal conductance between the heater and/or temperature sensor and the substrate is greater than a thermal conductance between the heater and/or temperature sensor and the main body surface.

Abstract: A device and method are disclosed in which gas is caused to flow parallel to a flow of source material to form a gas shroud. The gas shroud may protect flow of source material from being disrupted by a cross flow of gas. The gas shroud may also limit heating of a physical shroud through which the source material passes and limit accumulation of source material on the physical shroud by deforming a plasma bubble formed during irradiation of the source material so that the plasma bubble does not come too near the physical shroud. A device and method are also disclosed for establishing an additional transverse flow of gas so that the gas shroud does not cause source material contamination of an optic used to collect light generated during irradiation of the source material.

Abstract: A substrate table to support a substrate on a substrate supporting area, the substrate table having a heat transfer fluid channel at least under the substrate supporting area, and a plurality of heaters and/or coolers to thermally control the heat transfer fluid in the channel at a location under the substrate supporting area.

Abstract: A contaminant trap is used in an EUV radiation source apparatus. An EUV radiation beam is generated and focused through a low pressure gaseous atmosphere into a virtual source point. The EUV radiation creates a plasma in the low pressure hydrogen atmosphere through which it passes. A contaminant trap including electrodes is located in or around radiation beam as it approaches the virtual source point. A DC biasing source is connected to the electrodes to create an electric field oriented to deflect out of the beam path contaminant particles that have been negatively charged by the plasma. Additional RF electrodes and/or an ionizer enhance the plasma to increase the charging of the particles. The deflecting electrodes can be operated with RF bias for a short time, to ensure dissipation of the enhanced plasma.

Abstract: Disclosed herein is a computer-implemented method for determining an overlapping process window (OPW) of an area of interest on a portion of a design layout for a device manufacturing process for imaging the portion onto a substrate, the method comprising: obtaining a plurality of features in the area of interest; obtaining a plurality of values of one or more processing parameters of the device manufacturing process; determining existence of defects, probability of the existence of defects, or both in imaging the plurality of features by the device manufacturing process under each of the plurality of values; and determining the OPW of the area of interest from the existence of defects, the probability of the existence of defects, or both.

Abstract: A property of a target structure is measured based on intensity of an image of the target. The method includes (a) obtaining an image of the target structure; (b) defining (1204) a plurality of candidate regions of interest, each candidate region of interest comprising a plurality of pixels in the image; (c) defining (1208, 1216) an optimization metric value for the candidate regions of interest based at least partly on signal values of pixels within the region of interest; (d) defining (1208, 1216) a target signal function which defines a contribution of each pixel in the image to a target signal value. The contribution of each pixel depends on (i) which candidate regions of interest contain that pixel and (ii) optimization metric values of those candidate regions of interest.

Abstract: A substrate table of an immersion lithographic apparatus is disclosed which comprises a barrier configured to collect liquid. The barrier surrounds the substrate and is spaced apart from the substrate. In this way any liquid which is spilt from the liquid supply system can be collected to reduce the risk of contamination of delicate components of the lithographic projection apparatus.

Abstract: A method of cleaning a lithography apparatus using an aerosol spray is described. The spray from the aerosol is contained in a space.

Abstract: A substrate is loaded onto a substrate support of a lithographic apparatus, after which the apparatus measures locations of substrate alignment marks. These measurements define first correction information allowing the apparatus to apply a pattern at one or more desired locations on the substrate. Additional second correction information is used to enhance accuracy of pattern positioning, in particular to correct higher order distortions of a nominal alignment grid. The second correction information may be based on measurements of locations of alignment marks made when applying a previous pattern to the same substrate. The second correction information may alternatively or in addition be based on measurements made on similar substrates that have been patterned prior to the current substrate.