1798 results about "Metrology" patented technology

Methods are disclosed for measuring target structures formed by a lithographic process on a substrate. A grating structure within the target is smaller than an illumination spot and field of view of a measurement optical system. The optical system has a first branch leading to a pupil plane imaging sensor and a second branch leading to a substrate plane imaging sensor. A spatial light modulator is arranged in an intermediate pupil plane of the second branch of the optical system. The SLM imparts a programmable pattern of attenuation that may be used to correct for asymmetries between the first and second modes of illumination or imaging. By use of specific target designs and machine-learning processes, the attenuation patterns may also be programmed to act as filter functions, enhancing sensitivity to specific parameters of interest, such as focus.

A smart grid gateway which includes a onboard computer programmed to provide load measurement and control of at least one local resource or asset. At least one metrology module is configured to provide metering of the at least one local resource or asset. At least one LAN module is configured to communicate with the at least one local resource or asset. At least one WAN module is configured to communicate with a network operations center.

Methods are disclosed for measuring target structures formed by a lithographic process on a substrate. A grating or other structure within the target is smaller than an illumination spot and field of view of a measurement optical system. The position of an image of the component structure varies between measurements, and a first type of correction is applied to reduce the influence on the measured intensities, caused by differences in the optical path to and from different positions. A plurality of structures may be imaged simultaneously within the field of view of the optical system, and each corrected for its respective position. The measurements may comprise first and second images of the same target under different modes of illumination and/or imaging, for example in a dark field metrology application. A second type of correction may be applied to reduce the influence of asymmetry between the first and second modes of illumination or imaging, for example to permit a more accurate overly measurement in a semiconductor device manufacturing process.

An overlay measurement apparatus has a polarized light source for illuminating a sample with a polarized light beam and an optical system to capture light that is scattered by the sample. The optical system includes a polarizer for transmitting an orthogonal polarization component that is orthogonal to a polarization direction of the polarized light beam. A detector measures intensity of the orthogonal polarization component. A processing unitise connected to the detector, and is arranged to process the orthogonal polarization component for overlay metrology measurement using asymmetry data derived from the orthogonal polarization component.

Alignment accuracy between two or more patterned layers is measured using a metrology target comprising substantially overlapping diffraction gratings formed in a test area of the layers being tested. An optical instrument illuminates all or part of the target area and measures the optical response. The instrument can measure transmission, reflectance, and/or ellipsometric parameters as a function of wavelength, polar angle of incidence, azimuthal angle of incidence, and/or polarization of the illumination and detected light. Overlay error or offset between those layers containing the test gratings is determined by a processor programmed to calculate an optical response for a set of parameters that include overlay error, using a model that accounts for diffraction by the gratings and interaction of the gratings with each others' diffracted field. The model parameters might also take account of manufactured asymmetries. The calculation may involve interpolation of pre-computed entries from a database accessible to the processor. The calculated and measured responses are iteratively compared and the model parameters changed to minimize the difference.

Methods and systems for performing measurements based on a measurement model integrating a metrology-based target model with a process-based target model. Systems employing integrated measurement models may be used to measure structural and material characteristics of one or more targets and may also be used to measure process parameter values. A process-based target model may be integrated with a metrology-based target model in a number of different ways. In some examples, constraints on ranges of values of metrology model parameters are determined based on the process-based target model. In some other examples, the integrated measurement model includes the metrology-based target model constrained by the process-based target model. In some other examples, one or more metrology model parameters are expressed in terms of other metrology model parameters based on the process model. In some other examples, process parameters are substituted into the metrology model.

A method for modeling diffraction includes constructing a theoretical model of the subject. A numerical method is then used to predict the output field that is created when an incident field is diffracted by the subject. The numerical method begins by computing the output field at the upper boundary of the substrate and then iterates upward through each of the subject's layers. Structurally simple layers are evaluated directly. More complex layers are discretized into slices. A finite difference scheme is performed for these layers using a recursive expansion of the field-current ratio that starts (or has a base case) at the lowermost slice. The combined evaluation, through all layers, creates a scattering matrix that is evaluated to determine the output field for the subject.

A method of measuring a three-dimensional device in a wafer is provided. The method comprises the step of forming a trench in the wafer. The trench has a facet passing through the three-dimensional device a predetermined offset from a desired image position. The method further comprises iteratively, until a remaining distance between the facet and the desired image position is less than a predetermined threshold, adjusting one or more parameters of a polishing beam based on the remaining distance, polishing the facet with the polishing beam to position the facet closer to the desired image position, and measuring the remaining distance.

A method for measuring three-dimensional devices in a wafer comprises the step of obtaining a plurality of cross-sectional images of a corresponding plurality of three-dimensional devices in the wafer. The plurality of three-dimensional devices have essentially identical geometries. Each cross-sectional image is obtained from a plane in the corresponding three-dimensional device at a predetermined distance from a fiducial mark thereof. The predetermined distance is different for each of the plurality of cross-sectional images. The method further comprises the step of determining the geometries of the plurality of three-dimensional devices based on the cross-sectional images thereof.

A new way of mixing instrumental and digital means is described for the general field of wave front sensing. The present invention describes the use, the definition and the utility of digital operators, called digital wave front operators (DWFO) or digital lenses (DL), specifically designed for the digital processing of wave fronts defined in amplitude and phase. DWFO are of particular interest for correcting undesired wave front deformations induced by instrumental defects or experimental errors. DWFO may be defined using a mathematical model, e.g. a polynomial function, which involves coefficients. The present invention describes automated and semi-automated procedures for calibrating or adjusting the values of these coefficients. These procedures are based on the fitting of mathematical models on reference data extracted from specific regions of a wave front called reference areas, which are characterized by the fact that specimen contributions are a priori known in reference areas. For example, reference areas can be defined in regions where flat surfaces of a specimen produce a constant phase function. The present invention describes also how DWFO can be defined by extracting reference data along one-dimensional (1D) profiles. DWFO can also be defined in order to obtain a flattened representation of non-flat area of a specimen. Several DWFO or DL can be combined, possibly in addition with procedures for calculating numerically the propagation of wave fronts. A DWFO may also be defined experimentally, e.g. by calibration procedures using reference specimens. A method for generating a DWFO by filtering in the Fourier plane is also described. All wave front sensing techniques may benefit from the present invention. The case of a wave front sensor based on digital holography, e.g. a digital holographic microscope (DHM), is described in more details. The use of DWFO improves the performance, in particular speed and precision, and the ease of use of instruments for wave front sensing. The use of DWFO results in instrumental simplifications, costs reductions, and enlarged the field of applications. The present invention defines a new technique for imaging and metrology with a large field of applications in material and life sciences, for research and industrial applications.

Design driven inspection/metrology methods and apparatus are provided. A recipe is a set of instructions including wafer processing parameters, inspection parameters, or control parameters for telling an inspection/metrology system how to inspect/measure a wafer. Design data is imported into a recipe extraction system that recognizes instances of target structures and configures recipe parameters accordingly, thereby reducing manual instrument setup time, improving inspection/measurement accuracy, and improving fabrication efficiency.

A system and method of automated civil infrastructure metrology for inspection, analysis, and information modeling utilizes an unmanned aerial vehicle (UAV) equipped with a position tracking system and digital cameras to capture a plurality of images of a structure to be inspected. The UAV is flown in a scan pattern around the structure while continually capturing images of the structure while position and orientation data is also recorded and linked for each of the images. Image processing and pattern recognition software algorithms are used to analyze the images and create an information model of the structure which is then used to carry out a virtual inspection of the structure in a three dimensional software environment.

Methods and systems for performing semiconductor metrology directly on device structures are presented. A measurement model is created based on measured training data collected from at least one device structure. The trained measurement model is used to calculate process parameter values, structure parameter values, or both, directly from measurement data collected from device structures of other wafers. In some examples, measurement data from multiple targets is collected for model building, training, and measurement. In some examples, the use of measurement data associated with multiple targets eliminates, or significantly reduces, the effect of under layers in the measurement result, and enables more accurate measurements. Measurement data collected for model building, training, and measurement may be derived from measurements performed by a combination of multiple, different measurement techniques.

Metrology methods, systems and targets are provided, which implement a side by side paradigm. Adjacent cells with periodic structures are used to extract the overlay error, e.g., by introducing controllable phase shifts or image shifts which enable algorithmic computation of the overlay. The periodic structures are designed to exhibit a rotational symmetry to support the computation and reduce errors.

Methods and systems for performing measurements of semiconductor structures and materials based on scatterometry measurement data are presented. Scatterometry measurement data is used to generate an image of a material property of a measured structure based on the measured intensities of the detected diffraction orders. In some examples, a value of a parameter of interest is determined directly from the map of the material property of the measurement target. In some other examples, the image is compared to structural characteristics estimated by a geometric, model-based parametric inversion of the same measurement data. Discrepancies are used to update the geometric model of the measured structure and improve measurement performance. This enables a metrology system to converge on an accurate parametric measurement model when there are significant deviations between the actual shape of a manufactured structure subject to model-based measurement and the modeled shape of the structure.

The present invention includes a method and system for determining the profile of a structure in an integrated circuit from a measured signal, the signal measured off the structure with a metrology device, selecting a best match of the measured signal in a profile data space, the profile data space having data points with a specified extent of non-linearity, and performing a refinement procedure to determine refined profile parameters. One embodiment includes a refinement procedure comprising finding a polyhedron in a function domain of cost functions of the profile library signals and profile parameters and minimizing the total cost function using the weighted average method. Other embodiments include profile parameter refinement procedures using sensitivity analysis, a clustering approach, regression-based methods, localized fine-resolution refinement library method, iterative library refinement method, and other cost optimization or refinement algorithms, procedures, and methods. Refinement of profile parameters may be invoked automatically or invoked based on predetermined criteria such as exceeding an error metric between the measured signal versus the best match profile library.

Hybrid metrology apparatus (1000, 1100, 1200, 1300, 1400) measures a structure (T) manufactured by lithography. An EUV metrology apparatus (244, IL1/DET1) irradiates the structure with EUV radiation and detects a first spectrum from the structure. Another metrology apparatus (240, IL2/DET2) irradiates the structure with second radiation comprising EUV radiation or longer-wavelength radiation and detects a second spectrum. Using the detected first spectrum and the detected second spectrum together, a processor (MPU) determines a property (CD/OV) of the structure. The spectra can be combined in various ways. For example, the first detected spectrum can be used to control one or more parameters of illumination and/or detection used to capture the second spectrum, or vice versa. The first spectrum can be used to distinguish properties of different layers (T1, T2) in the structure. First and second radiation sources (SRC1, SRC2) may share a common drive laser (LAS).