Abstract: Angle-resolved reflectometers and reflectometry methods are provided, which comprise a coherent light source, an optical system arranged to scan a test pattern using a spot of coherent light from the light source to yield realizations of the light distribution in the collected pupil, wherein the spot covers a part of the test pattern and the scanning is carried out optically or mechanically according to a scanning pattern, and a processing unit arranged to generate a composite image of the collected pupil distribution by combining the pupil images. Metrology systems and methods are provided, which reduce diffraction errors by estimating, quantitatively, a functional dependency of measurement parameters on aperture sizes and deriving, from identified diffraction components of the functional dependency which relate to the aperture sizes, correction terms for the measurement parameters with respect to the measurement conditions.

Abstract: A system for providing illumination to a measurement head for optical metrology is configured to combine illumination beams from a plurality of illumination sources to deliver illumination at one or more selected wavelengths to the measurement head. The intensity and/or spatial coherence of illumination delivered to the measurement head is controlled. Illumination at one or more selected wavelengths is delivered from a broadband illumination source configured for providing illumination at a continuous range of wavelengths.

Abstract: A spectral filter includes a curved filtering element including a concave surface forming a portion of a sphere. The concave surface may be positioned to receive light diverging from an output face of an optical fiber located at a first location proximate to a center of the sphere corresponding to the concave surface. The concave surface may transmit a first portion of a spectrum of the light. The concave surface may further reflect and focus a second portion of the spectrum to a second location proximate to the center of the sphere. The spectral filter may further include a collector to direct the second portion of the spectrum away from the output face of the optical fiber.

Abstract: Angle-resolved reflectometers and reflectometry methods are provided, which comprise a coherent light source, an optical system arranged to scan a test pattern using a spot of coherent light from the light source to yield realizations of the light distribution in the collected pupil, wherein the spot covers a part of the test pattern and the scanning is carried out optically or mechanically according to a scanning pattern, and a processing unit arranged to generate a composite image of the collected pupil distribution by combining the pupil images. Metrology systems and methods are provided, which reduce diffraction errors by estimating, quantitatively, a functional dependency of measurement parameters on aperture sizes and deriving, from identified diffraction components of the functional dependency which relate to the aperture sizes, correction terms for the measurement parameters with respect to the measurement conditions.

Abstract: A metrology system includes an image device and a controller. The image device includes a spectrally-tunable illumination device and a detector to generate images of a sample having metrology target elements on two or more sample layers based on radiation emanating from the sample in response to illumination from the spectrally-tunable illumination device. The controller determines layer-specific imaging configurations of the imaging device to image the metrology target elements on the two or more sample layers within a selected image quality tolerance in which each layer-specific imaging configuration includes an illumination spectrum from the spectrally-tunable illumination device. The controller further receives one or more images of the metrology target elements on the two or more sample layers generated using the layer-specific imaging configurations. The controller further provides a metrology measurement based on the one or more images of the metrology target elements on the two or more sample layers.

Abstract: Angle-resolved reflectometers and reflectometry methods are provided, which comprise a coherent light source, an optical system arranged to scan a test pattern using a spot of coherent light from the light source to yield realizations of the light distribution in the collected pupil, wherein the spot covers a part of the test pattern and the scanning is carried out optically or mechanically according to a scanning pattern, and a processing unit arranged to generate a composite image of the collected pupil distribution by combining the pupil images. Metrology systems and methods are provided, which reduce diffraction errors by estimating, quantitatively, a functional dependency of measurement parameters on aperture sizes and deriving, from identified diffraction components of the functional dependency which relate to the aperture sizes, correction terms for the measurement parameters with respect to the measurement conditions.

Abstract: Angle-resolved reflectometers and reflectometry methods are provided, which comprise a coherent light source, an optical system arranged to scan a test pattern using a spot of coherent light from the light source to yield realizations of the light distribution in the collected pupil, wherein the spot covers a part of the test pattern and the scanning is carried out optically or mechanically according to a scanning pattern, and a processing unit arranged to generate a composite image of the collected pupil distribution by combining the pupil images. Metrology systems and methods are provided, which reduce diffraction errors by estimating, quantitatively, a functional dependency of measurement parameters on aperture sizes and deriving, from identified diffraction components of the functional dependency which relate to the aperture sizes, correction terms for the measurement parameters with respect to the measurement conditions.

Abstract: The disclosure is directed to a system and method of controlling spectral attributes of illumination. According to various embodiments, a portion of illumination including an excluded selection of illumination spectra is blocked, while another portion of the illumination including a transmitted selection of illumination spectra is directed along an illumination path. In some embodiments, optical metrology is performed utilizing the spectrally controlled illumination to enhance measurement capability. For instance, the spectral attributes of illumination utilized to analyze different portions of a sample, such as different semiconductor layers, may be selected according to certain measurement characteristics associated with the analyzed portions of the sample.

Abstract: A metrology system includes an illumination source to generate an illumination beam, a multi-channel spectral filter, a focusing element to direct illumination from the single optical column to a sample, and at least one detector to capture the illumination collected from the sample. The multi-channel spectral filter includes two or more filtering channels having two or more channel beam paths. The two or more filtering channels filter illumination propagating along the two or more channel beam paths based on two or more spectral transmissivity distributions. The multi-channel spectral filter further includes a channel selector to direct at least a portion of the illumination beam into at least one selected filtering channel to filter the illumination beam. The multi-channel spectral filter further includes at least one beam combiner to combine illumination from the two or more filtering channels to a single optical column.

Abstract: A tunable spectral filter includes a first tunable dispersive element, a first optical element, a spatial filtering element located at the focal plane, a second optical element, and a second dispersive element. The first tunable dispersive element introduces spectral dispersion to an illumination beam with an adjustable dispersion. The first optical element focuses the illumination beam at a focal plane in which a distribution of a spectrum of the spectrally-dispersed illumination beam at the focal plane is controllable by adjusting the dispersion of the first tunable dispersive element. The spatial filtering element filters the spectrum of the illumination beam based on the distribution of the spectrum of the illumination beam at the focal plane. The second optical element collects the spectrally-dispersed illumination beam transmitted from the spatial filtering element. The second tunable dispersive element removes the dispersion introduced by the first tunable dispersive element from the illumination beam.

Abstract: The disclosure is directed to various apodization schemes for pupil imaging scatterometry. In some embodiments, the system includes an apodizer disposed within a pupil plane of the illumination path. In some embodiments, the system further includes an illumination scanner configured to scan a surface of the sample with at least a portion of apodized illumination. In some embodiments, the system includes an apodized pupil configured to provide a quadrupole illumination function. In some embodiments, the system further includes an apodized collection field stop. The various embodiments described herein may be combined to achieve certain advantages.

Abstract: A system for providing illumination to a measurement head for optical metrology is configured to combine illumination beams from a plurality of illumination sources to deliver illumination at one or more selected wavelengths to the measurement head. The intensity and/or spatial coherence of illumination delivered to the measurement head is controlled. Illumination at one or more selected wavelengths is delivered from a broadband illumination source configured for providing illumination at a continuous range of wavelengths.

Abstract: Systems and methods are provided which derive target characteristics from interferometry images taken at multiple phase differences between target beams and reference beams yielding the interferometry images. The illumination of the target and the reference has a coherence length of less than 30 microns to enable scanning the phase through the coherence length of the illumination. The interferometry images are taken at the pupil plane and/or in the field plane to combine angular and spectroscopic scatterometry data that characterize and correct target topography and enhance the performance of metrology systems.

Abstract: The disclosure is directed to systems for providing illumination to a measurement head for optical metrology. In some embodiments of the disclosure, illumination beams from a plurality of illumination sources are combined to deliver illumination at one or more selected wavelengths to the measurement head. In some embodiments of the disclosure, intensity and/or spatial coherence of illumination delivered to the measurement head is controlled. In some embodiments of the disclosure, illumination at one or more selected wavelengths is delivered from a broadband illumination source configured for providing illumination at a continuous range of wavelengths.

Abstract: Methods are provided for deriving a partially continuous dependency of metrology metric(s) on recipe parameter(s), analyzing the derived dependency, determining a metrology recipe according to the analysis, and conducting metrology measurement(s) according to the determined recipe. The dependency may be analyzed in form of a landscape such as a sensitivity landscape in which regions of low sensitivity and/or points or contours of low or zero inaccuracy are detected, analytically, numerically or experimentally, and used to configure parameters of measurement, hardware and targets to achieve high measurement accuracy. Process variation is analyzed in terms of its effects on the sensitivity landscape, and these effects are used to characterize the process variation further, to optimize the measurements and make the metrology both more robust to inaccuracy sources and more flexible with respect to different targets on the wafer and available measurement conditions.

Abstract: The disclosure is directed to a system and method of controlling spectral attributes of illumination. According to various embodiments, a portion of illumination including an excluded selection of illumination spectra is blocked, while another portion of the illumination including a transmitted selection of illumination spectra is directed along an illumination path. In some embodiments, optical metrology is performed utilizing the spectrally controlled illumination to enhance measurement capability. For instance, the spectral attributes of illumination utilized to analyze different portions of a sample, such as different semiconductor layers, may be selected according to certain measurement characteristics associated with the analyzed portions of the sample.

Abstract: The disclosure is directed to a system and method of controlling spectral attributes of illumination. According to various embodiments, a portion of illumination including an excluded selection of illumination spectra is blocked, while another portion of the illumination including a transmitted selection of illumination spectra is directed along an illumination path. In some embodiments, optical metrology is performed utilizing the spectrally controlled illumination to enhance measurement capability. For instance, the spectral attributes of illumination utilized to analyze different portions of a sample, such as different semiconductor layers, may be selected according to certain measurement characteristics associated with the analyzed portions of the sample.

Abstract: The disclosure is directed to various apodization schemes for pupil imaging scatterometry. In some embodiments, the system includes an apodizer disposed within a pupil plane of the illumination path. In some embodiments, the system further includes an illumination scanner configured to scan a surface of the sample with at least a portion of apodized illumination. In some embodiments, the system includes an apodized pupil configured to provide a quadrupole illumination function. In some embodiments, the system further includes an apodized collection field stop. The various embodiments described herein may be combined to achieve certain advantages.

Abstract: The present invention includes an illumination source, at least one illumination symmetrization module (ISM) configured to symmetrize at least a portion of light emanating from the illumination source, a first beam splitter configured to direct a first portion of light processed by the ISM along an object path to a surface of one or more specimens and a second portion of light processed by the ISM along a reference path, and a detector disposed along a primary optical axis, wherein the detector is configured to collect a portion of light reflected from the surface of the one or more specimens.

Abstract: The disclosure is directed to various apodization schemes for pupil imaging scatterometry. In some embodiments, the system includes an apodizer disposed within a pupil plane of the illumination path. In some embodiments, the system further includes an illumination scanner configured to scan a surface of the sample with at least a portion of apodized illumination. In some embodiments, the system includes an apodized pupil configured to provide a quadrupole illumination function. In some embodiments, the system further includes an apodized collection field stop. The various embodiments described herein may be combined to achieve certain advantages.