Abstract: A parameterized geometric model of a structure can be determined based on spectra from a wafer metrology tool. The structure can have geometry-induced anisotropic effects. Dispersion parameters of the structure can be determined from the parameterized geometric model. This can enable metrology techniques to measure nanostructures that have geometries and relative positions with surrounding structures that induce non-negligible anisotropic effects. These techniques can be used to characterize process steps involving metal and semiconductor targets in semiconductor manufacturing of, for example, FinFETs or and gate-all-around field-effect transistors.

Abstract: Optical elements that efficiently propagate x-ray radiation over a desired energy range and reject radiation outside the desired energy range are presented herein. In one aspect, one or more optical elements of an x-ray based system include an integrated optical filter including one or more material layers that absorb radiation having energy outside the desired energy band. In general, the integrated filter improves the optical performance of an x-ray based system by suppressing reflectivity within infrared (IR), visible (vis), ultraviolet (UV), extreme ultraviolet (EUV) portions of the spectrum, or any other undesired wavelength region. In a further aspect, one or more diffusion barrier layers prevent degradation of the integrated optical filter, prevent diffusion between the integrated optical filter and other material layers, or both. In some embodiments, the thickness of one or more material layers of an integrated optical filter vary over the spatial area of the filter.

Abstract: Optical elements that efficiently propagate x-ray radiation over a desired energy range and reject radiation outside the desired energy range are presented herein. In one aspect, one or more optical elements of an x-ray based system include an integrated optical filter including one or more material layers that absorb radiation having energy outside the desired energy band. In general, the integrated filter improves the optical performance of an x-ray based system by suppressing reflectivity within infrared (IR), visible (vis), ultraviolet (UV), extreme ultraviolet (EUV) portions of the spectrum, or any other undesired wavelength region. In a further aspect, one or more diffusion barrier layers prevent degradation of the integrated optical filter, prevent diffusion between the integrated optical filter and other material layers, or both. In some embodiments, the thickness of one or more material layers of an integrated optical filter vary over the spatial area of the filter.

Abstract: An additive-manufacturing head includes: a ring-shape laser beam forming unit having axicon lenses facing each other and a convex lens between the axicon lenses to form a laser beam entering through the axicon lens into a ring-shape laser beam and emit the ring-shape laser beam from the other axicon lens; a lens moving mechanism to move the convex lens in the optical axis direction of the laser beam; a laser beam emitting unit to emit the ring-shape laser beam toward a workpiece; and a material powder feeding tube having an outlet which is disposed inside the ring-shape laser beam emitted from the laser beam emitting unit and from which material powder is released, to feed the material powder from the outlet toward the workpiece. Accordingly, the additive-manufacturing head capable of freely controlling the size of the laser-beam-irradiated region and the laser beam intensity distribution on the workpiece is provided.

Abstract: Methods and systems for positioning a specimen and characterizing an x-ray beam incident onto the specimen in a Transmission, Small-Angle X-ray Scatterometry (T-SAXS) metrology system are described herein. A specimen positioning system locates a wafer vertically and actively positions the wafer in six degrees of freedom with respect to the x-ray illumination beam without attenuating the transmitted radiation. In some embodiments, a cylindrically shaped occlusion element is scanned across the illumination beam while the detected intensity of the transmitted flux is measured to precisely locate the beam center. In some other embodiments, a periodic calibration target is employed to precisely locate the beam center. The periodic calibration target includes one or more spatially defined zones having different periodic structures that diffract X-ray illumination light into distinct, measurable diffraction patterns.

Abstract: Methods and systems for performing overlay and edge placement errors based on Soft X-Ray (SXR) scatterometry measurement data are presented herein. Short wavelength SXR radiation focused over a small illumination spot size enables measurement of design rule targets or in-die active device structures. In some embodiments, SXR scatterometry measurements are performed with SXR radiation having energy in a range from 10 to 5,000 electronvolts. As a result, measurements at SXR wavelengths permit target design at process design rules that closely represents actual device overlay. In some embodiments, SXR scatterometry measurements of overlay and shape parameters are performed simultaneously from the same metrology target to enable accurate measurement of Edge Placement Errors. In another aspect, overlay of aperiodic device structures is estimated based on SXR measurements of design rule targets by calibrating the SXR measurements to reference measurements of the actual device target.

Abstract: Methods and systems for generating measurement models of nanowire based semiconductor structures based on re-useable, parametric models are presented herein. Metrology systems employing these models are configured to measure structural and material characteristics (e.g., material composition, dimensional characteristics of structures and films, etc.) associated with nanowire semiconductor fabrication processes. The re-useable, parametric models of nanowire based semiconductor structures enable measurement model generation that is substantially simpler, less error prone, and more accurate. As a result, time to useful measurement results is significantly reduced, particularly when modelling complex, nanowire based structures. The re-useable, parametric models of nanowire based semiconductor structures are useful for generating measurement models for both optical metrology and x-ray metrology, including soft x-ray metrology and hard x-ray metrology.

Abstract: Methods and systems for more efficient X-Ray scatterometry measurements of on-device structures are presented herein. X-Ray scatterometry measurements of one or more structures over a measurement area includes a decomposition of the one or more structures into a plurality of sub-structures, a decomposition of the measurement area into a plurality of sub-areas, or both. The decomposed structures, measurement areas, or both, are independently simulated. The scattering contributions of each of the independently simulated decomposed structures are combined to simulate the actual scattering of the measured structures within the measurement area. In a further aspect, measured intensities and modelled intensities including one or more incidental structures are employed to perform measurement of structures of interest. In other further aspects, measurement decomposition is employed to train a measurement model and to optimize a measurement recipe for a particular measurement application.

Abstract: Methods and systems for measuring structural and material characteristics of semiconductor structures based on wavelength resolved, soft x-ray reflectometry (WR-SXR) at multiple diffraction orders are presented. WR-SXR measurements are simultaneous, high throughput measurements over multiple diffraction orders with broad spectral width. The availability of wavelength resolved signal information at each of the multiple diffraction orders improves measurement accuracy and throughput. Each non-zero diffraction order includes multiple measurement points, each different measurement point associated with a different wavelength. In some embodiments, WR-SXR measurements are performed with x-ray radiation energy in a range of 10-5,000 electron volts at grazing angles of incidence in a range of 1-45 degrees. In some embodiments, the illumination beam is controlled to have relatively high divergence in one direction and relatively low divergence in a second direction, orthogonal to the first direction.

Abstract: Methods and systems for measuring structural and material characteristics of semiconductor structures based on combined x-ray reflectometry (XRR) and x-ray photoelectron spectroscopy (XPS) are presented herein. A combined XRR and XPS system includes an x-ray illumination source and x-ray illumination optics shared by both the XRR and XPS measurement subsystems. This increases throughput and measurement accuracy by simultaneously collecting XRR and XPS measurement data from the same area of the wafer. A combined XRR and XPS system improves measurement accuracy by employing XRR measurement data to improve measurements performed by the XPS subsystem, and vice-versa. In addition, a combined XRR and XPS system enables simultaneous analysis of both XRR and XPS measurement data to more accurately estimate values of one of more parameters of interest. In a further aspect, any of measurement spot size, photon flux, beam shape, beam diameter, and illumination energy are independently controlled.

Abstract: Methods and systems for measuring structural and material characteristics of semiconductor structures based on combined x-ray reflectometry (XRR) and x-ray photoelectron spectroscopy (XPS) are presented herein. A combined XRR and XPS system includes an x-ray illumination source and x-ray illumination optics shared by both the XRR and XPS measurement subsystems. This increases throughput and measurement accuracy by simultaneously collecting XRR and XPS measurement data from the same area of the wafer. A combined XRR and XPS system improves measurement accuracy by employing XRR measurement data to improve measurements performed by the XPS subsystem, and vice-versa. In addition, a combined XRR and XPS system enables simultaneous analysis of both XRR and XPS measurement data to more accurately estimate values of one of more parameters of interest. In a further aspect, any of measurement spot size, photon flux, beam shape, beam diameter, and illumination energy are independently controlled.

Abstract: Multilayer targets enabling fast and accurate, absolute calibration and alignment of X-ray based measurement systems are described herein. The multilayer calibration targets have very high diffraction efficiency and are manufactured using fast, low cost production techniques. Each target includes a multilayer structure built up with pairs of X-ray transparent and X-ray absorbing materials. The layers of the multilayer target structure is oriented parallel to an incident X-ray beam. Measured diffraction patterns indicate misalignment in position and orientation between the incident X-Ray beam and the multilayer target. In another aspect, a composite multilayer target includes at least two multilayer structures arranged adjacent one another along a direction aligned with the incident X-ray beam, adjacent one another along a direction perpendicular to the incident X-ray beam, or a combination thereof. In some embodiments, the multilayer structures are spatially separated from one another by a gap distance.

Abstract: Methods and systems for performing co-located measurements of semiconductor structures with two or more measurement subsystems are presented herein. To achieve a sufficiently small measurement box size, the metrology system monitors and corrects the alignment of the measurement spot of each metrology subsystem with a metrology target to achieve maximum co-location of the measurement spots of each metrology subsystem with the metrology target. In another aspect, measurements are performed simultaneously by two or more metrology subsystems at high throughput at the same wafer location. Furthermore, the metrology system effectively decouples simultaneously acquired measurement signals associated with each measurement subsystem. This maximizes signal information associated with simultaneous measurements of the same metrology by two or more metrology subsystems.

Abstract: 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.

Abstract: Methods and systems for performing co-located measurements of semiconductor structures with two or more measurement subsystems are presented herein. To achieve a sufficiently small measurement box size, the metrology system monitors and corrects the alignment of the measurement spot of each metrology subsystem with a metrology target to achieve maximum co-location of the measurement spots of each metrology subsystem with the metrology target. In another aspect, measurements are performed simultaneously by two or more metrology subsystems at high throughput at the same wafer location. Furthermore, the metrology system effectively decouples simultaneously acquired measurement signals associated with each measurement subsystem. This maximizes signal information associated with simultaneous measurements of the same metrology by two or more metrology subsystems.

Abstract: Methods and systems for evaluating the geometric characteristics of patterned structures are presented. More specifically, geometric structures generated by one or multiple patterning processes are measured by two or more metrology systems in accordance with a hybrid metrology methodology. A measurement result from one metrology system is communicated to at least one other metrology systems to increase the measurement performance of the receiving system. Similarly, a measurement result from the receiving metrology system is communicated back to the sending metrology system to increase the measurement performance of the sending system. In this manner, measurement results obtained from each metrology system are improved based on measurement results received from other cooperating metrology systems. In some examples, metrology capability is expanded to measure parameters of interest that were previously unmeasurable by each metrology system operating independently.

Abstract: In some embodiments, a first plurality of electron-microscope images for respective instances of a semiconductor structure is obtained from a first source. The electron-microscope images of the first plurality show different values of one or more semiconductor-fabrication parameters. A model is trained that specifies a relationship between the first plurality of electron-microscope images and the values of the one or more semiconductor-fabrication parameters. A second plurality of electron-microscope images for respective instances of the semiconductor structure on one or more semiconductor wafers is collected. The one or more semiconductor wafers are distinct from the first source. Values of the one or more semiconductor-fabrication parameters for the second plurality of electron-microscope images are predicted using the model.

Abstract: A system, method and computer program product are provided for selecting signals to be measured utilizing a metrology tool that optimizes the precision of the measurement. The technique includes the steps of simulating a set of signals for measuring one or more parameters of a metrology target. A normalized Jacobian matrix corresponding to the set of signals is generated, a subset of signals in the simulated set of signals is selected that optimizes a performance metric associated with measuring the one or more parameters of the metrology target based on the normalized Jacobian matrix, and a metrology tool is utilized to collect a measurement for each signal in the subset of signals for the metrology target. For a given number of signals collected by the metrology tool, this technique optimizes the precision of such measurements over conventional techniques that collect signals uniformly distributed over a range of process parameters.

Abstract: Methods and systems for measuring process induced errors in a multiple patterning semiconductor fabrication process based on measurements of a specimen and process information from one or more previous process steps employed to fabricate the specimen are presented herein. A metrology tool is employed after a number of process steps have been executed. The metrology tool measures structural parameters of interest of metrology targets on the wafer based on measured signals and process information, and communicates correctable process parameter values to one or more process tools involved in the previous process steps. When executed by the appropriate process tool, the correctable process parameter values reduce process induced errors in the geometry of the structures fabricated by the process flow. In another aspect, multiple metrology tools are used to control a fabrication process in combination with process information from one or more process steps in the process flow.

Abstract: Disclosed are apparatus and methods for characterizing a plurality of structures of interest on a semiconductor wafer. A plurality of spectra signals are measured from a particular structure of interest at a plurality of azimuth angles from one or more sensors of a metrology system. A difference spectrum is determined based on the spectra signals obtained for the azimuth angles. A quality indication of the particular structure of interest is determined and reported based on analyzing the difference spectrum.