Abstract: Disclosed is a metrology apparatus for measurement of a target formed on a substrate by a lithographic process and associated method. The metrology apparatus comprises a radiation source operable to provide first radiation; a configured solid high harmonic generation medium being configured to receive and be excited by said first radiation to generate high harmonic second radiation from an output surface of the configured solid high harmonic generation medium; and a detection arrangement operable to detect said second radiation, at least a portion of which having been scattered by said target. The configured solid high harmonic generation medium is configured to shape the beam of said second radiation and/or separate said first and second radiation.

Abstract: Disclosed is a metrology apparatus and method for measurement of a diffractive structure on a substrate. The metrology apparatus comprises a radiation source operable to provide first radiation for excitation of the diffractive structure such that high harmonic second radiation is generated from said diffractive structure and/or substrate; and a detection arrangement operable to detect said second radiation, at least a portion of which having been diffracted by said diffractive structure.

Abstract: A metrology apparatus (302) includes a higher harmonic generation (HHG) radiation source for generating (310) EUV radiation. Operation of the HHG source is monitored using a wavefront sensor (420) which comprises an aperture array (424, 702) and an image sensor (426). A grating (706) disperses the radiation passing through each aperture so that the image detector captures positions and intensities of higher diffraction orders for different spectral components and different locations across the beam. In this way, the wavefront sensor can be arranged to measure a wavefront tilt for multiple harmonics at each location in said array. In one embodiment, the apertures are divided into two subsets (A) and (B), the gratings (706) of each subset having a different direction of dispersion. The spectrally resolved wavefront information (430) is used in feedback control (432) to stabilize operation of the HGG source, and/or to improve accuracy of metrology results.

Abstract: A method for determining a characteristic of a feature in an object, the feature being disposed below a surface of the object is disclosed. The surface of the object is irradiated with a pulsed pump radiation beam so as to produce an acoustic wave in the object. The surface of the object is then irradiated with a measurement radiation beam. A portion of the measurement radiation beam scattered from the surface is received and a characteristic of the feature in the object is determined from at least a portion of the measurement radiation beam scattered from the surface within a measurement time period. A temporal intensity distribution of the pulsed pump radiation beam is selected such that in the measurement time period a signal to background ratio is greater than a signal to background ratio achieved using a single pulse of the pulsed pump radiation beam.

Abstract: As increasing numbers of layers, using increasing numbers of specific materials, are deposited on substrates, it becomes increasingly difficult to detect alignment marks accurately for, for example, applying a desired pattern onto a substrate using a lithographic apparatus, in part due to one or more of the materials used in one or more of the layers being wholly or partially opaque to the radiation used to detect alignment marks. In a first step, the substrate is illuminated with excitation radiation. In a second step, at least one effect associated with a reflected material effect scattered by a buried structure is measured. The effect may, for example, include a physical displacement of the surface of the substrate. In a third step, at least one characteristic of the structure based on the measured effect is derived.

Abstract: A metrology apparatus (302) includes a higher harmonic generation (HHG) radiation source for generating (310) EUV radiation. Operation of the HHG source is monitored using a wavefront sensor (420) which comprises an aperture array (424, 702) and an image sensor (426). A grating (706) disperses the radiation passing through each aperture so that the image detector captures positions and intensities of higher diffraction orders for different spectral components and different locations across the beam. In this way, the wavefront sensor can be arranged to measure a wavefront tilt for multiple harmonics at each location in said array. In one embodiment, the apertures are divided into two subsets (A) and (B), the gratings (706) of each subset having a different direction of dispersion. The spectrally resolved wavefront information (430) is used in feedback control (432) to stabilize operation of the HGG source, and/or to improve accuracy of metrology results.

Abstract: A metrology apparatus (302) includes a higher harmonic generation (HHG) radiation source for generating (310) EUV radiation. Operation of the HHG source is monitored using a wavefront sensor (420) which comprises an aperture array (424, 702) and an image sensor (426). A grating (706) disperses the radiation passing through each aperture so that the image detector captures positions and intensities of higher diffraction orders for different spectral components and different locations across the beam. In this way, the wavefront sensor can be arranged to measure a wavefront tilt for multiple harmonics at each location in said array. In one embodiment, the apertures are divided into two subsets (A) and (B), the gratings (706) of each subset having a different direction of dispersion. The spectrally resolved wavefront information (430) is used in feedback control (432) to stabilize operation of the HGG source, and/or to improve accuracy of metrology results.

Abstract: A method for determining a characteristic of a feature in an object, the feature being disposed below a surface of the object is disclosed. The surface of the object is irradiated with a pulsed pump radiation beam so as to produce an acoustic wave in the object. The surface of the object is then irradiated with a measurement radiation beam. A portion of the measurement radiation beam scattered from the surface is received and a characteristic of the feature in the object is determined from at least a portion of the measurement radiation beam scattered from the surface within a measurement time period. A temporal intensity distribution of the pulsed pump radiation beam is selected such that in the measurement time period a signal to background ratio is greater than a signal to background ratio achieved using a single pulse of the pulsed pump radiation beam.

Abstract: As increasing numbers of layers, using increasing numbers of specific materials, are deposited on substrates, it becomes increasingly difficult to detect alignment marks accurately for, for example, applying a desired pattern onto a substrate using a lithographic apparatus, in part due to one or more of the materials used in one or more of the layers being wholly or partially opaque to the radiation used to detect alignment marks. In a first step, the substrate is illuminated with excitation radiation. In a second step, at least one effect associated with a reflected material effect scattered by a buried structure is measured. The effect may, for example, include a physical displacement of the surface of the substrate. In a third step, at least one characteristic of the structure based on the measured effect is derived.

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 lithographic apparatus comprises comprise a substrate table constructed to hold a substrate; and a sensor configured to sense a position of an alignment mark provided onto the substrate held by the substrate table. The sensor comprises a source of radiation configured to illuminate the alignment mark with a radiation beam, a detector configured to detect the radiation beam, having interacted with the alignment mark, as an out of focus optical pattern, and a data processing system. The data processing system is configured to receive image data representing the out of focus optical pattern, and process the image data for determining alignment information, comprising applying a lensless imaging algorithm to the out of focus optical pattern.

Abstract: A metrology apparatus (302) includes a higher harmonic generation (HHG) radiation source for generating (310) EUV radiation. Operation of the HHG source is monitored using a wavefront sensor (420) which comprises an aperture array (424, 702) and an image sensor (426). A grating (706) disperses the radiation passing through each aperture so that the image detector captures positions and intensities of higher diffraction orders for different spectral components and different locations across the beam. In this way, the wavefront sensor can be arranged to measure a wavefront tilt for multiple harmonics at each location in said array. In one embodiment, the apertures are divided into two subsets (A) and (B), the gratings (706) of each subset having a different direction of dispersion. The spectrally resolved wavefront information (430) is used in feedback control (432) to stabilize operation of the HGG source, and/or to improve accuracy of metrology results.

Abstract: A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). The lithographic apparatus has an inspection apparatus with an EUV radiation source. The radiation source emits a radiation beam that includes coherent radiation of a specific wavelength. The beam propagates to illumination optical system, which focuses the radiation beam into a focused beam of illuminating radiation. The illumination optical system illuminates a three-dimensional product structure on the substrate, which scatters the illuminating radiation. On the surface of a detector, the radiation scattered by the product structure forms a diffraction pattern that is used to reconstruct data describing the three-dimensional product structure.

Abstract: A lithographic apparatus comprises comprise a substrate table constructed to hold a substrate; and a sensor configured to sense a position of an alignment mark provided onto the substrate held by the substrate table. The sensor comprises a source of radiation configured to illuminate the alignment mark with a radiation beam, a detector configured to detect the radiation beam, having interacted with the alignment mark, as an out of focus optical pattern, and a data processing system. The data processing system is configured to receive image data representing the out of focus optical pattern, and process the image data for determining alignment information, comprising applying a lensless imaging algorithm to the out of focus optical pattern.

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 lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). The lithographic apparatus has an inspection apparatus with an EUV radiation source. The radiation source emits a radiation beam that includes coherent radiation of a specific wavelength. The beam propagates to illumination optical system, which focuses the radiation beam into a focused beam of illuminating radiation. The illumination optical system illuminates a three-dimensional product structure on the substrate, which scatters the illuminating radiation. On the surface of a detector, the radiation scattered by the product structure forms a diffraction pattern that is used to reconstruct data describing the three-dimensional product structure.

Abstract: Metrology targets are formed on a substrate (W) by a lithographic process. A target (T) comprising one or more grating structures is illuminated with spatially coherent radiation under different conditions. Radiation (650) diffracted by from said target area interferes with reference radiation (652) interferes with to form an interference pattern at an image detector (623). One or more images of said interference pattern are captured. From the captured image(s) and from knowledge of the reference radiation a complex field of the collected scattered radiation at the detector. A synthetic radiometric image (814) of radiation diffracted by each grating is calculated from the complex field. From the synthetic radiometric images (814, 814?) of opposite portions of a diffractions spectrum of the grating, a measure of asymmetry in the grating is obtained. Using suitable targets, overlay and other performance parameters of the lithographic process can be calculated from the measured asymmetry.

Abstract: Metrology targets are formed on a substrate (W) by a lithographic process. A target (T) comprising one or more grating structures is illuminated with spatially coherent radiation under different conditions. Radiation (650) diffracted by from said target area interferes with reference radiation (652) interferes with to form an interference pattern at an image detector (623). One or more images of said interference pattern are captured. From the captured image(s) and from knowledge of the reference radiation a complex field of the collected scattered radiation at the detector. A synthetic radiometric image (814) of radiation diffracted by each grating is calculated from the complex field. From the synthetic radiometric images (814, 814?) of opposite portions of a diffractions spectrum of the grating, a measure of asymmetry in the grating is obtained. Using suitable targets, overlay and other performance parameters of the lithographic process can be calculated from the measured asymmetry.

Abstract: A microscopic imaging apparatus to provide an image of a sample. The apparatus includes an illumination system to provide an illumination beam with radiation; and a sensor constructed and arranged to receive: a first image of a first diffraction pattern created by diffraction of the illumination beam on the sample; and a second image of a second diffraction pattern created by diffraction of the illumination beam on the sample.