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.

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.

A process for sizing two-dimensional nanostructures includes providing the nanostructures to a liquid-liquid interface, providing probe particles to the liquid-liquid interface, obtaining an image of the nanostructures and the probe particles, and processing the image to ascertain a size property of the nanostructures.

An optical system and method are presented for use in measurements on an upper surface of a layered sample when located in a measurement plane. The optical system is configured as a normal-incidence system having an illumination channel and a collection channel, and comprises an objective lens unit and a light propagation affecting device. The objective lens unit is accommodated in the illumination and collection channels, thereby defining a common optical path for propagation of illuminating light from the illumination channel toward an illuminating region in the measurement plane and for propagation of light returned from measurement plane to the collection channel. The light propagation affecting device comprises an apertured structure located in at least one of the illumination and collection channels, and configured to provide angular obscuration of light propagation path for blocking angular segments associated with light propagation from regions outside the illuminated region.

An optical measurement system comprises a polarization beam splitter for dividing an incident beam into a reference beam and a measurement beam, a first beam splitter for reflecting the measurement beam to form a first reflected measurement beam, a spatial light modulator for modulating the first reflected measurement beam to form a modulated measurement beam, a condenser lens for focusing the modulated measurement beam to an object to form a penetrating measurement beam, an objective lens for converting the penetrating measurement beam into a parallel measurement beam, a mirror for reflecting the parallel measurement beam to form an object beam, a second beam splitter for reflecting the reference beam to a path coincident with that of the object beam, and a camera for receiving an interference signal generated by the reference beam and the object beam to generate an image of the object.

Example implementations relate to an inspection method for training a measurement machine to accurately measure side joint lengths and detecting a defect among a plurality of solder joints. The method includes receiving a first data representing the side joint lengths of the plurality of solder joints measured by a first measurement machine and a second data representing the side joint lengths measured by a second measurement machine. Further, the method includes determining a correlation value based on a statistical analysis of a relationship between the first data and the second data. The method further includes updating an algorithm used by the first measurement machine to measure the side joint lengths, based on the correlation value to reduce deviation between the first data and the second data. Later, the updated algorithm is used as a dimensional metrology in the first measurement machine for detecting the defect in the solder joints.

Apparatus include a polarization state generator situated to provide an interferometer source beam with a region of polarized source light with a polarization state that is in-plane as subsequently incident on a sample and a region of polarized source light with a polarization state that is perpendicular to in-plane as subsequently incident on the sample, and an interferometer unit configured to split the interferometer source beam into test and reference arm beams, to direct the test arm beam to the sample and the reference arm beam to a reference surface, and to recombine the test and reference arm beams to produce an interferometer output beam. Methods use a polarization state generator to produce an interferometer source beam with a region of polarized source light with a polarization state that is in-plane as subsequently incident on a sample and a region of polarized source light with a polarization state that is perpendicular to in-plane as subsequently incident on the sample, and use an interferometer unit which splits the interferometer source beam into test and reference arm beams, directs the test arm beam to the sample and the reference arm beam to a reference surface, and recombines the test and reference arm beams to produce an interferometer output beam.

A spectral confocal measurement device includes a light source portion, configured to emit a broad-spectrum light beam with a certain wavelength range in a first predetermined path; an optical sampling portion, configured to converge the broad-spectrum light beam emitted from the light source portion on different measurement surfaces of an object to be measured, and output a reflected light in a second predetermined path that is different from a reverse direction of the first predetermined path; and a measurement portion, configured to receive and process the reflected light from the optical sampling portion to obtain a measurement result. The device can improve measurement accuracy and reduce production costs. In addition, a spectral confocal measurement method is also provided.

The present description relates to a device for line-scanning optical coherence tomographic microscopy. The device comprises an interferometric microscope comprising a reference arm, an object arm configured to receive an object, a beam splitter coupling said object arm and reference arm to a light source and to a sensor, and a first microscope objective arranged on said object arm. It further comprises a one-dimensional confocal spatial filtering device configured to interact with said light source in order to illuminate said object along a focal line located in an object space of the first microscope objective, and a device for unidirectional scanning of said focal line, which device is arranged on said object arm upstream of said first microscope objective and is configured to scan the focal line in a lateral direction (y) substantially perpendicular to an optical axis (z) of said first microscope objective.

An information processing apparatus that executes processing of obtaining, from an interference fringe image that is a two-dimensional distribution of intensity of interference fringes of object light and reference light, a phase difference image that is a two-dimensional distribution of a phase difference between the object light and the reference light, and obtaining a shape of an object to be observed based on the phase difference image includes at least one processor configured to acquire object-related information regarding the object to be observed, read out, from a storage unit in which the object-related information and a shape profile indicating the shape of the object to be observed are stored in association with each other, the shape profile corresponding to the acquired object-related information, and perform phase connection with respect to the phase difference image with reference to the read-out shape profile.