Abstract: An method for generating illuminating radiation in an illumination apparatus for use in an inspection apparatus for use in lithographic processes is described. A driving radiation beam is provided that comprises a plurality of radiation pulses. The beam is split into first and second pluralities of driving radiation pulses. Each plurality of driving radiation pulses has a controllable characteristic. The first and second pluralities may be used to generate an illuminating radiation beam with an output wavelength spectrum. The first and second controllable characteristics are controlled so as to control first and second portions respectively of the output wavelength spectrum of the illuminating radiation beam.

Abstract: A position measurement system includes an interferometer to determine a position of an object. The interferometer is arranged to generate a first, second and third signals representative of the position by irradiating respective first, second and third areas of a reflective surface of the object. Along a line, the first and second areas are at a first distance relative to each other, the second and third areas are at a second distance relative to each other, and the first and third areas are at a third distance relative to each other. The interferometer is arranged to provide a rotation signal representative of a rotation of the object along an axis based on the first, second and third signals. The axis is parallel to the reflective surface and perpendicular to the line.

Abstract: An illumination system (IL) for a lithographic apparatus comprising a polarization adjustment apparatus (15) arranged to receive linearly polarized radiation, the polarization adjustment apparatus comprising regions which are configured to rotate the polarization orientation by different amounts, a directing apparatus (6) operable to direct the radiation through one or more regions of the polarization adjustment apparatus, a controller (CN) configured to control the directing apparatus so as to control which of the one or more regions of the polarization adjustment apparatus radiation is directed through, wherein the controller is configured to limit which of the regions radiation is directed through to one or more regions which rotate the orientation of the linear polarization by substantially the same amount, and a diffuser configured to receive radiation output from the polarization adjustment apparatus and increase a range of angles at which the radiation propagates whilst substantially conserving the pol

Abstract: A Lorentz actuator includes: a magnet arrangement; a coil arrangement; and a current controller for supplying a current to the coil arrangement; wherein the magnet and coil arrangement are moveable relative to each other in a main direction, wherein the coil arrangement has a first and second coil portion that are separately operable by the current controller, such that when the same current is supplied to the first coil portion as is supplied to the second coil portion, Lorentz forces generated in the main direction by the first and second coil portions are also the same, and wherein the current controller is configured to supply a current to the first and second coil portions with a phase difference in order to compensate for parasitic reluctance and/or Lorentz forces in an auxiliary direction perpendicular to the main direction.

Abstract: A lithographic apparatus includes a patterning device support to support a patterning device, the patterning device system including a moveable structure movably arranged relative to an object, a patterning device holder movably arranged relative to the movable structure to hold the patterning device, an actuator to move the movable structure relative to the object, and an ultra short stroke actuator to move the patterning device holder with respect to the movable structure; a substrate support to hold a substrate; a projection system to project a patterned radiation beam onto a target portion of the substrate; a transmission image sensor for measuring a position of the patterned radiation beam downstream of the projection system; and a calibrator for determining a relationship between magnitude of an applied control signal to the ultra short stroke actuator and resulting change in position of the patterned radiation beam and/or patterning device holder and/or patterning device.

Abstract: A method for adjusting a lithography process, wherein processing parameters of the lithography process include a first group of processing parameters and a second group of processing parameters, the method including: obtaining a change of the second group of processing parameters; determining a change of a sub- process window (sub-PW) as a result of the change of the second group of processing parameters, wherein the sub-PW is spanned by only the first group of processing parameters; and adjusting the first group of processing parameters based on the change of the sub-PW.

Abstract: Target structures such as overlay gratings (Ta and Tb) are formed on a substrate (W) by a lithographic process. The first target is illuminated with a spot of first radiation (456a, Sa) and simultaneously the second target is illuminated with a spot of second radiation (456b, Sb). A sensor (418) detects at different locations, portions (460x?, 460x+) of said first radiation that have been diffracted in a first direction by features of the first target and portions (460y?, 460y+) of said second radiation that have been diffracted in a second direction by features of the second target. Asymmetry in X and Y directions can be detected simultaneously, reducing the time required for overlay measurements in X and Y. The two spots of radiation at soft x-ray wavelength can be generated simply by exciting two locations (710a, 710b) in a higher harmonic generation (HHG) radiation source or inverse Compton scattering source.

Abstract: Capacitive measurements for monitoring vapor or deposits from a vapor in a radiation source for a lithography apparatus. The measurements may be used to control operation of the radiation source. In one particular arrangement measurements from a plurality of capacitors are used to distinguish between changes in capacitance caused by the vapor and changes in capacitance caused by deposits from the vapor.

Abstract: A substrate has three or more overlay gratings formed thereon by a lithographic process. Each overlay grating has a known overlay bias. The values of overlay bias include for example two values in a region centered on zero and two values in a region centered on P/2, where P is the pitch of the gratings. Overlay is calculated from asymmetry measurements for the gratings using knowledge of the different overlay bias values and an assumed non-linear relationship between overlay and target asymmetry, thereby to correct for feature asymmetry. The periodic relationship in the region of zero bias and P/2 has gradients of opposite sign. The calculation allows said gradients to have different magnitudes as well as opposite sign. The calculation also provides information on feature asymmetry and other processing effects. This information is used to improve subsequent performance of the measurement process, and/or the lithographic process.

Abstract: Disclosed is a process monitoring method, and an associated metrology apparatus. The method comprises: comparing measured target response spectral sequence data relating to the measurement response of actual targets to equivalent reference target response sequence data relating to a measurement response of the targets as designed; and performing a process monitoring action based on the comparison of said measured target response sequence data and reference target response sequence data. The method may also comprise determining stack parameters from the measured target response spectral sequence data and reference target response spectral sequence data.

Abstract: A metrology method, and associated metrology apparatus, that includes measuring a target formed in at least two layers on a substrate by a lithographic process and capturing at least one corresponding pair of non-zeroth diffraction orders, for example in an image field, to obtain measurement data. A simulation of a measurement of the target as defined in terms of geometric parameters of the target, the geometric parameters including one or more variable geometric parameters is performed and a difference between the measurement data and simulation data is minimized, so as to directly reconstruct values for the one or more variable geometric parameters.

Abstract: A target structure (T) made by lithography or used in lithography is inspected by irradiating the structure at least a first time with EUV radiation (304) generated by inverse Compton scattering. Radiation (308) scattered by the target structure in reflection or transmission is detected (312) and properties of the target structure are calculated by a processor (340) based on the detected scattered radiation. The radiation may have a first wavelength in the EUV range of 0.1 nm to 125 nm. Using the same source and controlling an electron energy, the structure may be irradiated multiple times with different wavelengths within the EUV range, and/or with shorter (x-ray) wavelengths and/or with longer (UV, visible) wavelengths. By rapid switching of electron energy in the inverse Compton scattering source, irradiation at different wavelengths can be performed several times per second.

Abstract: A scatterometer is used to measure a property of structures on a substrate. A target grating comprises lines arranged periodically over an distance gp in a first direction, each line individually extending a distance gL in a second direction. The grating is illuminated with a spot of radiation and diffracted radiation is detected and used to calculate a measurement of CD, side wall angle and the like. The spot defines a field of view customized to the grating such that an extent fP of the spot in said first direction is greater than distance gp while an extent fL of the spot in said second direction is less than distance gL- The grating may be smaller than conventional gratings. The calculation can be simplified and made more robust, using a mathematical model that assumes that the grating is finite in the first direction but infinite in the second direction.

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 lithographic apparatus applies a device pattern at multiple fields across a substrate. A height map is decomposed into a plurality of components. A first height map component represents topographical variations associated with the device pattern. One or more further height map components represent other topographical variations. Using each height map component, control set-points are calculated according to a control algorithm specific to each component. The control set-points calculated for the different height map components are then combined and used to control imaging of the device pattern to the substrate. The specific control algorithms can be different from one another, and may have differing degrees of nonlinearity. The combining of the different set-points can be linear. Focus control in the presence of device-specific topography and other local variations can be improved.

Abstract: An immersion lithographic apparatus including: a liquid confinement structure configured to supply and confine immersion liquid to an immersion space between a final lens element of a projection system and a surface of the substrate and/or of a substrate table; and a passageway-former between the projection system and the liquid confinement structure, and a passageway between the passageway-former and an optically active part of the final lens element, the passageway being in liquid communication via an opening with the immersion space and extending radially outwardly, with respect to an optical axis of the projection system, at least to an edge of an exposed bottom surface of the final lens element and being constructed and configured such that in use it is filled with liquid from the immersion space by capillary action.

Abstract: A system is disclosed for reducing overlay errors by controlling gas flow around a patterning device of a lithographic apparatus. The lithographic apparatus includes an illumination system configured to condition a radiation beam. The lithographic apparatus further includes a movable stage comprising a support structure that may be configured to support a patterning device. The patterning device may be configured to impart the radiation beam with a pattern in its cross-section to form a patterned radiation beam. In addition, the lithographic apparatus comprises a plate (410) positioned between the movable stage (401) and the projection system (208). The plate includes an opening (411) that comprises a first sidewall (411a) and a second sidewall (411b). The plate may be configured to provide a gas flow pattern (424) in a region between the movable stage and the projection system that is substantially perpendicular to an optical axis of the illumination system.

Abstract: A projection lens of an EUV-lithographic projection exposure system with at least two reflective optical elements each comprising a body and a reflective surface for projecting an object field on a reticle onto an image field on a substrate if the projection lens is exposed with an exposure power of EUV light, wherein the bodies of at least two reflective optical elements comprise a material with a temperature dependent coefficient of thermal expansion which is zero at respective zero cross temperatures, and wherein the absolute value of the difference between the zero cross temperatures is more than 6K.

Abstract: A radiation source for a lithographic apparatus uses a plurality of fiber lasers to ignite a fuel droplet at an ignition location to generate EUV radiation. The fiber lasers may be provided to emit parallel to an optical axis and a telescopic optical system is provided to focus the lasers at the ignition location, or the lasers may be directed towards the optical axis with a final focus lens being used to reduce beam waist. The lasers may be provided in two or more groups to allow them to be independently controlled and some of the lasers may be focused at a different location to provide a pre-pulse. Radiation from fiber lasers may also be combined using dichroic mirrors.

Abstract: A lithographic apparatus includes a number of sensors for measuring positions of features on a substrate prior to applying a pattern. Each sensor includes an imaging optical system. Position measurements are extracted from pixel data supplied by an image detector in each sensor. The imaging optical system includes one or more light field modulating elements and the processor processes the pixel data as a light-field image to extract the position measurements. The data processor may derive from each light-field image a focused image of a feature on the substrate, measuring positions of several features simultaneously, even though the substrate is not at the same level below all the sensors. The processor can also include corrections to reduce depth dependency of an apparent position of the feature include a viewpoint correction. The data processor can also derive measurements of heights of features on the substrate.