Abstract: An apparatus and method to determine a property of a substrate by measuring, in the pupil plane of a high numerical aperture lens, an angle-resolved spectrum as a result of radiation being reflected off the substrate. The property may be angle and wavelength dependent and may include the intensity of TM- and TE-polarized radiation and their relative phase difference.

Abstract: A laser driven light source comprises laser and focusing optics. These produce a beam of radiation focused on a plasma forming zone within a container containing a gas (e.g., Xe). Collection optics collects photons emitted by a plasma maintained by the laser radiation to form a beam of output radiation. Plasma has an elongate form (L>d) and collecting optics is configured to collect photons emerging in the longitudinal direction from the plasma. The brightness of the plasma is increased compared with sources which collect radiation emerging transversely from the plasma. A metrology apparatus using the light source can achieve greater accuracy and/or throughput as a result of the increased brightness. Back reflectors may be provided. Microwave radiation may be used instead of laser radiation to form the plasma.

Abstract: Calibration of an angularly resolved scatterometer is performed by measuring a target in two or more different arrangements. The different arrangements cause radiation being measured in an outgoing direction to be different combinations of radiation illuminating the target from ingoing directions. A reference mirror measurement may also be performed. The measurements and modeling of the difference between the first and second arrangements is used to estimate separately properties of the ingoing and outgoing optical systems. The modeling may account for symmetry of the respective periodic target. The modeling typically accounts for polarizing effects of the ingoing optical elements, the outgoing optical elements and the respective periodic target. The polarizing effects may be described in the modeling by Jones calculus or Mueller calculus. The modeling may include a parameterization in terms of basis functions such as Zernike polynomials.

Abstract: An apparatus and method to determine a property of a substrate by measuring, in the pupil plane of a high numerical aperture lens, an angle-resolved spectrum as a result of radiation being reflected off the substrate. The property may be angle and wavelength dependent and may include the intensity of TM- and TE-polarized radiation and their relative phase difference.

Abstract: A metrology apparatus is arranged to illuminate a plurality of targets with an off-axis illumination mode. Images of the targets are obtained using only one first order diffracted beam. Where the target is a composite grating, overlay measurements can be obtained from the intensities of the images of the different gratings. Overlay measurements can be corrected for errors caused by variations in the position of the gratings in an image field.

Abstract: An apparatus and method to determine a property of a substrate by measuring, in the pupil plane of a high numerical aperture lens, an angle-resolved spectrum as a result of radiation being reflected off the substrate. The property may be angle and wavelength dependent and may include the intensity of TM- and TE-polarized radiation and their relative phase difference.

Abstract: An apparatus and method to determine a property of a substrate by measuring, in the pupil plane of a high numerical aperture lens, an angle-resolved spectrum as a result of radiation being reflected off the substrate. The property may be angle and wavelength dependent and may include the intensity of TM- and TE-polarized radiation and their relative phase difference.

Abstract: Calibration of an angularly resolved scatterometer is performed by measuring a target in two or more different arrangements. The different arrangements cause radiation being measured in an outgoing direction to be different combinations of radiation illuminating the target from ingoing directions. A reference mirror measurement may also be performed. The measurements and modeling of the difference between the first and second arrangements is used to estimate separately properties of the ingoing and outgoing optical systems. The modeling may account for symmetry of the respective periodic target. The modeling typically accounts for polarizing effects of the ingoing optical elements, the outgoing optical elements and the respective periodic target. The polarizing effects may be described in the modeling by Jones calculus or Mueller calculus. The modeling may include a parameterization in terms of basis functions such as Zernike polynomials.

Abstract: A scatterometer, configured to measure a property of a substrate, includes a radiation source which produces a radiation spot on a target formed on the surface of the substrate, the size of the radiation spot being smaller than the target in one direction along the target, the position of the radiation spot being moved along the surface in a series of discrete steps. A detector detects a spectrum of the radiation beam reflected from the target and produces measurement signals representative of the spectrum corresponding to each position of the radiation spot. A processor processes the measurement signals produced by the detector corresponding to each position of the radiation spot and derives a single value for the property.

Abstract: A metrology apparatus is arranged to illuminate a plurality of targets with an off-axis illumination mode. Images of the targets are obtained using only one first order diffracted beam. Where the target is a composite grating, overlay measurements can be obtained from the intensities of the images of the different gratings. Overlay measurements can be corrected for errors caused by variations in the position of the gratings in an image field.

Abstract: A method of assessing a model of a substrate is presented. A scatterometry measurement is taken using radiation at a first wavelength. The wavelength of the radiation is then changed and a further scatterometry measurement taken. If the scatterometry measurements are consistent across a range of wavelengths then the model is sufficiently accurate. However, if the scatterometry measurements change as the wavelength changes then the model of the substrate is not sufficiently accurate.

Abstract: An apparatus and method to determine a property of a substrate by measuring, in the pupil plane of a high numerical aperture lens, an angle-resolved spectrum as a result of radiation being reflected off the substrate. The property may be angle and wavelength dependent and may include the intensity of TM- and TE-polarized radiation and their relative phase difference.

Abstract: A scatterometer has a focus sensor arranged to detect whether the target being measured is in a correct focal plane. A modulation is applied to a component of the focus sensor or the scatterometer such that a defocus as measured by the focus sensor varies according to a certain function. From knowledge of the modulation, the gain of the sensor can be calibrated.

Abstract: An apparatus and method to determine a property of a substrate by measuring, in the pupil plane of a high numerical aperture lens, an angle-resolved spectrum as a result of radiation being reflected off the substrate. The property may be angle and wavelength dependent and may include the intensity of TM- and TE-polarized radiation and their relative phase difference.

Abstract: For angular resolved spectrometry a radiation beam is used having an illumination profile having four quadrants is used. The first and third quadrants are illuminated whereas the second and fourth quadrants aren't illuminated. The resulting pupil plane is thus also divided into four quadrants with only the zeroth order diffraction pattern appearing in the first and third quadrants and only the first order diffraction pattern appearing in the second and third quadrants.

Abstract: A scatterometer has a focus sensor arranged to detect whether the target being measured is in a correct focal plane. A modulation is applied to a component of the focus sensor or the scatterometer such that a defocus as measured by the focus sensor varies according to a certain function. From knowledge of the modulation, the gain of the sensor can be calibrated.

Abstract: A lithographic apparatus according to one embodiment includes an alignment system for aligning a substrate. The alignment system comprises an illuminator system configured to illuminate an alignment mark on the substrate with an illumination spot, the alignment mark comprising a plurality of lines and spaces. The system also includes a combiner system configured to transfer two images of the illuminated alignment mark without spatial filtering of the images, rotate the images 180° relatively to each other, and combine the two images; and a detection system configured to detect an alignment signal from the combined images and to determine a unique alignment position by selecting a specific one of extreme values in the detected alignment signal.

Abstract: A metrology apparatus for measuring a parameter of a microscopic structure on a substrate, the apparatus comprising a supercontinuum light source arranged to generate a measurement beam, an optical system arranged to direct the measurement beam onto the substrate and a sensor for detecting radiation reflected and/or diffracted by the structure.

Abstract: A lithographic apparatus according to one embodiment of the invention includes an alignment subsystem configured to align the substrate on the substrate table relative to the patterning structure. The alignment structure comprises a non-periodic feature which may be detectable as e.g. a capture position or a check position using a reference grating in the alignment subsystem. The non-periodic feature may cause a phase effect in the detected signal of the alignment subsystem or an amplitude effect.

Abstract: A lithographic apparatus according to one embodiment of the invention includes an alignment subsystem configured to align the substrate on the substrate table relative to the patterning structure. The alignment structure comprises a non-periodic feature which may be detectable as e.g. a capture position or a check position using a reference grating in the alignment subsystem. The non-periodic feature may cause a phase effect in the detected signal of the alignment subsystem or an amplitude effect.