Methods and systems for detecting and classifying defects based on the phase of dark field scattering from a sample are described herein. In some embodiments, throughput is increased by detecting and classifying defects with the same optical system. In one aspect, a defect is classified based on the measured relative phase of scattered light collected from at least two spatially distinct locations in the collection pupil. The phase difference, if any, between the light transmitted through any two spatially distinct locations at the pupil plane is determined from the positions of the interference fringes in the imaging plane. The measured phase difference is indicative of the material composition of the measured sample. In another aspect, an inspection system includes a programmable pupil aperture device configured to sample the pupil at different, programmable locations in the collection pupil.

Apparatuses and methods are described for detecting inclusions in glass. The apparatuses and methods employ a laser that is configured to project a laser sheet at a first angle from one side of a glass sheet, and a camera configured to capture images from a second angle from another side of the glass sheet. The glass sheet is moved thorough the laser sheet while the camera captures images. One or more processing devices execute image processing algorithms to identify areas of the glass sheet containing inclusions based on the captured images. In some examples, the identified areas of the glass sheet are revisited to confirm they contain inclusions.

An optical system configured to measure a raised or receded surface feature on a surface of a sample may comprise a broadband light source; a tunable filter configured to filter broadband light emitted from the broadband light source and to generate a first light beam at a selected wavelength; a linewidth control element configured to receive the first light beam and to generate a second light beam having a predefined linewidth and a predetermined coherence length; collimating optics optically coupled to the second light beam and configured to collimate the second light beam; collinearizing optics optically coupled to the collimating optics and configured to align the collimated second light beam onto the raised or receded surface feature of the sample, and a processor system and at least one digital imager configured to measure a height of the raised surface or depth of the receded surface from light reflected at least from those surfaces.

A method for inspecting a transparent workpiece comprises: directing light from an illumination source onto a plurality of defects formed in the transparent workpiece, wherein the plurality of defects extends in a defect direction, wherein the transparent workpiece comprises a first surface and a second surface; detecting a scattering image signal from light scattered by the plurality of defects using an imaging system, wherein an imaging axis of the imaging system extends at a non-zero imaging angle relative to the defect direction, wherein entireties of at least a subset of the plurality of defects are within a depth of field of the imaging system; and generating a three-dimensional image of at least one of the plurality of defects based on the scattering signal.

A pattern inspection apparatus includes an illumination optical system to illuminate an inspection substrate on which a pattern is formed, an offset calculation circuit to calculate an offset amount which depends on an image accumulation time of each of a plurality of photo sensor elements arrayed two-dimensionally, a time delay integration (TDI) sensor to include the plurality of photo sensor elements, to acquire an image of the inspection substrate by receiving a transmitted light or a reflected light from the inspection substrate by the plurality of photo sensor elements, to correct, using the offset amount, a pixel value of optical image data of an acquired image, and to output the optical image data having been corrected, and a comparison circuit to compare an optical image formed by the optical image data output from the TDI sensor with a reference image.

In a dark-field metrology method using a small target, a characteristic of an image of the target, obtained using a single diffraction order, is determined by fitting a combination fit function to the measured image. The combination fit function includes terms selected to represent aspects of the physical sensor and the target. Some coefficients of the combination fit function are determined based on parameters of the measurement process and/or target. In an embodiment the combination fit function includes jinc functions representing the point spread function of a pupil stop in the imaging system.

An optical system configured to measure a raised or receded surface feature on a surface of a sample may comprise a broadband light source; a tunable filter configured to filter broadband light emitted from the broadband light source and to generate a first light beam at a selected wavelength; a linewidth control element configured to receive the first light beam and to generate a second light beam having a predefined linewidth and a predetermined coherence length; collimating optics optically coupled to the second light beam and configured to collimate the second light beam; collinearizing optics optically coupled to the collimating optics and configured to align the collimated second light beam onto the raised or receded surface feature of the sample, and a processor system and at least one digital imager configured to measure a height of the raised surface or depth of the receded surface from light reflected at least from those surfaces.

An apparatus includes a main body, circuit assembly, lens, and clamping assembly. The main body includes an aperture that receives a wafer configured to receive a sample under study. The main body is configured to support the circuit assembly, which includes illumination sources that emit light of different colors such that total internal reflection is generated in the wafer. The main body is configured to provide support for the lens, and the clamping assembly mechanically coupled to the main body such that the lens is selectively positionable with respect to a camera lens. A microscopy imaging apparatus includes an illumination source, wafer, and charge-coupled device. The illumination source is configured to emit white light such that total internal reflection is generated in the wafer. The sample under study is disposed between the wafer and the charge coupled device, and the charge coupled device is configured to obtain an image of the sample under study upon illumination of the wafer by the illumination source.

An apparatus includes a lifting device and a motor assembly. The lifting device is disposed in a lifting device housing and is configured to adjust a vertical position of an optical component connected to the lifting device. The motor assembly is disposed in a motor housing and is configured to drive the lifting device to adjust the vertical position of the optical component. The lifting device housing, the motor housing, and the optical component are disposed in an ultra-high vacuum chamber of an enclosure. In the case of motor failure, the motor housing can be disconnected from the lifting device housing, and the motor assembly can be decoupled from the lifting device, such that the motor assembly can be replaced.

An optical metrology device is capable of detection of any combination of photoluminescence light, specular reflection of broadband light, and scattered light from a line across the width of a sample. The metrology device includes a first light source that produces a first illumination line on the sample. A scanning system may be used to scan an illumination spot across the sample to form the illumination line. A detector collects the photoluminescence light emitted along the illumination line. Additionally, a broadband illumination source may be used to produce a second illumination line on the sample, where the detector collects the broadband illumination reflected along the second illumination line. A signal collecting optic may collect the photoluminescence light and broadband light and focus it into a line, which is received by an optical conduit. The output end of the optical conduit has a shape that matches the entrance of the detector.