Abstract: A method for inspection includes directing a beam of X-rays to impinge upon an area of a sample containing first and second features formed respectively in first and second thin film layers, which are overlaid on a surface of the sample. A pattern of the X-rays diffracted from the first and second features is detected and analyzed in order to assess an alignment of the first and second features.

Abstract: A method for inspection of a sample includes irradiating the sample with a beam of X-rays and measuring a distribution of the X-rays that are emitted from the sample responsively to the beam, thereby generating an X-ray spectrum. An assessment is made of an effect on the spectrum of a non-uniformity of the beam, and the spectrum is corrected responsively to the effect.

Abstract: A method for testing a material applied to a surface of a sample includes directing an excitation beam, having a known beam-width and intensity cross-section, onto a region of the sample. An intensity of X-ray fluorescence emitted from the region responsively to the excitation beam is measured. A distribution of the material within the region is estimated, responsively to the measured intensity of the X-ray fluorescence and to the intensity cross-section of the excitation beam, with a spatial resolution that is finer than the beam-width.

Abstract: A method for inspection of a sample having a surface layer. The method includes acquiring a first reflectance spectrum of the sample while irradiating the sample with a collimated beam of X-rays, and processing the first reflectance spectrum to measure a diffuse reflection property of the sample. A second reflectance spectrum of the sample is acquired while irradiating the sample with a converging beam of the X-rays. The second reflectance spectrum is analyzed using the diffuse reflection property so as to determine a characteristic of the surface layer of the sample.

Abstract: A method for inspection of a sample that includes a first layer having a known reflectance property and a second layer formed over the first layer. The method includes directing radiation toward a surface of the sample and sensing the radiation reflected from the surface so as to generate a reflectance signal as a function of elevation angle relative to the surface. A feature due to reflection of the radiation from the first layer is identified in the reflectance signal. The reflectance signal is calibrated responsively to the identified feature and to the known reflectance property of the first layer. The calibrated reflectance signal is analyzed to determine a characteristic of the second layer. Other enhanced inspection methods are disclosed, as well.

Abstract: Apparatus for analysis of a sample includes a radiation source, which is adapted to direct a converging beam of X-rays toward a surface of the sample. At least one detector array is arranged to sense the X-rays scattered from the sample as a function of elevation angle over a range of elevation angles simultaneously, and to generate output signals responsively to the scattered X-rays. The detector array has a first configuration in which the detector array senses the X-rays that are reflected from the surface of the sample at a grazing angle, and a second configuration in which the detector array senses the X-rays that are diffracted from the surface in a vicinity of a Bragg angle of the sample. A signal processor processes the output signals so as to determine a characteristic of the surface layer of the sample.

Abstract: A method for inspection of a sample includes directing a beam of X-rays toward a sample and configuring an array of detector elements to capture the X-rays scattered from the sample. The sample is shifted in a direction parallel to the axis of the array between at least first and second positions, which positions are separated one from another by an increment that is not an integer multiple of the pitch of the array. At least first and second signals are generated by the detector elements responsively to the X-rays captured thereby while the sample is in at least the first and second positions, respectively. The first and second signals are combined so as to determine an X-ray scattering profile of the sample as a function of position along the axis.

Abstract: A method for X-ray analysis of a sample includes directing a beam of X-rays to impinge on an area of a periodic feature on a surface of the sample and receiving the X-rays scattered from the surface in a reflection mode so as to detect a spectrum of diffraction in the scattered X-rays as a function of azimuth. The spectrum of diffraction is analyzed in order to determine a dimension of the feature.

Abstract: A method for inspection of a sample includes irradiating the sample with a beam of X-rays, measuring a distribution of the X-rays that are emitted from the sample responsively to the beam, thereby generating an X-ray spectrum, and applying a multi-step analysis to the spectrum so as to determine one or more physical properties of a simulated model of the sample. The multi-step analysis includes spectrally analyzing the spectrum so as to determine one or more characteristic frequencies and fitting the simulated model to the spectrum by an iterative optimization process beginning from an initial condition determined by the one or more characteristic frequencies.

Abstract: X-ray apparatus, consisting of a single X-ray tube which is adapted to generate X-rays and a first optic which is adapted to focus a first portion of the X-rays onto a region of a sample via a first beam path, thereby generating first scattered X-rays from the region. The apparatus also includes a second optic which is adapted to focus a second portion of the X-rays onto the region of the sample via a second beam path, different from the first beam path, thereby generating second scattered X-rays from the region. A detector assembly simultaneously collects the first and the second scattered X-rays.

Abstract: A method for inspection of a sample having a surface layer. The method includes acquiring a first reflectance spectrum of the sample while irradiating the sample with a collimated beam of X-rays, and processing the first reflectance spectrum to measure a diffuse reflection property of the sample. A second reflectance spectrum of the sample is acquired while irradiating the sample with a converging beam of the X-rays. The second reflectance spectrum is analyzed using the diffuse reflection property so as to determine a characteristic of the surface layer of the sample.

Abstract: A method for inspection of a sample that includes a first layer having a known reflectance property and a second layer formed over the first layer. The method includes directing radiation toward a surface of the sample and sensing the radiation reflected from the surface so as to generate a reflectance signal as a function of elevation angle relative to the surface. A feature due to reflection of the radiation from the first layer is identified in the reflectance signal. The reflectance signal is calibrated responsively to the identified feature and to the known reflectance property of the first layer. The calibrated reflectance signal is analyzed to determine a characteristic of the second layer. Other enhanced inspection methods are disclosed, as well.

Abstract: A method for inspection of a sample includes irradiating the sample with a polychromatic beam of X-rays, comprising X-ray photons having a range of respective photon energies. The X-rays scattered from the sample are received at a plurality of scattering angles using one or more sensors, which generate output signals indicative of the respective photon energies of the X-rays photons that are incident thereon. The output signals are analyzed based on the photon energies so as to determine a scattering profile of the sample at a selected photon energy within the range.

Abstract: A method for X-ray analysis of a sample includes aligning an optical radiation source with an X-ray excitation source, so that a spot on the sample that is irradiated by an X-ray beam generated by the X-ray excitation source is illuminated with optical radiation generated by the optical radiation source. Optical radiation that is reflected from the sample is used to generate a first signal, which is indicative of an alignment of the spot on the sample. The X-ray beam is aligned, responsively to the first signal, so that the spot coincides with a target area of the sample. X-ray photons received from the spot on the sample, after aligning the X-ray beam, are used in generating a second signal that is indicative of a characteristic of the target area.

Abstract: A method for testing a surface of a sample includes irradiating the surface at a grazing incidence with a beam of radiation having a focal region, whereby the radiation is reflected from the surface. At least one of the focal region and the sample is adjusted through a plurality of adjustment stages within an adjustment range so as to vary a location of the focal region relative to the surface. Respective angular profiles of the radiation reflected from the surface are measured at the plurality of adjustment stages, and the angular profiles are compared in order to select an adjustment within the range at which the surface is in a desired alignment with the beam.

Abstract: A method for testing a surface includes finding respective first and second critical angles for total external reflection of radiation from an area of the surface at first and second wavelengths. The first and second critical angles are compared to determine an orientation of a tangent to the surface in the area.

Abstract: Apparatus for inspection of a sample includes a radiation source and an array of detector elements arranged to receive radiation from the surface due to irradiation of an area of the surface by the radiation source. The array has a first operative configuration for resolving the received radiation along a first axis perpendicular to the surface, and a second operative configuration for resolving the received radiation along a second axis parallel to the surface. A signal processor processes the signal from the detector array in the two configurations so as to determine a reflectance of the surface as a function of elevation angle relative to the surface and a scattering profile of the surface as a function of azimuthal angle in a plane of the surface.

Abstract: Apparatus for inspection of a sample includes a radiation source and an array of detector elements arranged to receive radiation from the surface due to irradiation of an area of the surface by the radiation source. The array has a first operative configuration for resolving the received radiation along a first axis perpendicular to the surface, and a second operative configuration for resolving the received radiation along a second axis parallel to the surface. A signal processor processes the signal from the detector array in the two configurations so as to determine a reflectance of the surface as a function of elevation angle relative to the surface and a scattering profile of the surface as a function of azimuthal angle in a plane of the surface.

Abstract: A method for testing a surface includes finding respective first and second critical angles for total external reflection of radiation from an area of the surface at first and second wavelengths. The first and second critical angles are compared to determine an orientation of a tangent to the surface in the area.

Abstract: Reflectometry apparatus includes a radiation source, adapted to irradiate a sample with radiation over a range of angles relative to a surface of the sample, and a detector assembly, positioned to receive the radiation reflected from the sample over the range of angles and to generate a signal responsive thereto. A shutter is adjustably positionable to intercept the radiation, the shutter having a blocking position, in which it blocks the radiation in a lower portion of the range of angles, thereby allowing the reflected radiation to reach the array substantially only in a higher portion of the range, and a clear position, in which the radiation in the lower portion of the range reaches the array substantially without blockage.