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: Disclosed are apparatus and methods for performing overlay metrology upon a target having at least two layers formed thereon. A target having a plurality of periodic structures for measuring overlay in at least two overlay directions is provided. A charged particle beam is scanned in a first direction across a plurality of scan swaths of the target and at a first tilt with respect to the target so that each edge of the periodic structures is scanned at an angle. The charged particle beam is scanned in a second direction, which is opposite the first direction, across the plurality of scan swaths and at a second tilt that is 180° from the first tilt. The first and second direction scanning operations are then repeated for different first and second tilts and a different plurality of scan swaths of the target so that the target is scanned symmetrically.

Abstract: A process control system includes a controller configured to generate a reference overlay signature based on one or more overlay reference layers of a sample, extrapolate the reference overlay signature to a set of correctable fields for the exposure of a current layer of the sample to generate a full-field reference overlay signature, identify one or more alignment fields of the set of correctable fields, generate an alignment-correctable signature by modeling alignment corrections for the set of correctable fields, subtract the alignment-correctable signature from the full-field reference overlay signature to generate feedforward overlay corrections for the current layer when the one or more overlay reference layers are the same as the one or more alignment reference layers, generate lithography tool corrections based on the feedforward overlay corrections, and provide the lithography tool corrections for the current layer to the lithography tool.

Abstract: Methods and systems for performing in-situ, selective spectral reflectometry (SSR) measurements of semiconductor structures disposed on a wafer are presented herein. Illumination light reflected from a wafer surface is spatially imaged. Signals from selected regions of the image are collected and spectrally analyzed, while other portions of the image are discarded. In some embodiments, a SSR includes a dynamic mirror array (DMA) disposed in the optical path at or near a field plane conjugate to the surface of the semiconductor wafer under measurement. The DMA selectively blocks the undesired portion of wafer image. In other embodiments, a SSR includes a hyperspectral imaging system including a plurality of spectrometers each configured to collect light from a spatially distinct area of a field image conjugate to the wafer surface. Selected spectral signals associated with desired regions of the wafer image are selected for analysis.

Abstract: A scanning electron microscopy (SEM) system includes a plurality of electron beam sources configured to generate a primary electron beam. The SEM system includes an electron-optical column array with a plurality of electron-optical columns. An electron-optical column includes a plurality of electron-optical elements. The plurality of electron-optical elements includes a deflector layer configured to be driven via a common controller shared by at least some of the plurality of electron-optical columns and includes a trim deflector layer configured to be driven by an individual controller. The plurality of electron-optical elements is arranged to form an electron beam channel configured to direct the primary electron beam to a sample secured on a stage, which emits an electron beam in response to the primary electron beam. The electron-optical column includes an electron detector. The electron beam channel is configured to direct the electron beam to the electron detector.

Abstract: An optical inspection system that utilizes sub-200 nm incident light beam to inspect a surface of an object for defects is described. The sub-200 nm incident light beam is generated by combining first light having a wavelength of about 1109 nm with second light having a wavelength of approximately 234 nm. An optical system includes optical components configured to direct the incident light beam to a surface of the object, and image relay optics are configured to collect and relay at least two channels of light to a sensor, where at least one channel includes light reflected from the object, and at least one channel includes light transmitted through the object. The sensor is configured to simultaneously detect both the reflected and transmitted light. A laser for generating the sub-200 nm incident light beam includes a fundamental laser, two or more harmonic generators, a frequency doubler and a two frequency mixing stages.

Abstract: The present disclosure is directed to a method of tool matching that employs an auto-learning feedback loop to update a library of key parameters. According to the method, measurements are performed on a control wafer to collect a set of parameters associated with the process/analysis tool that is being matched. When deviated parameters correlate to a correctable tool condition (i.e. a tool matching event), the parameters are added to the library of key parameters. These key or critical parameters may be monitored on a more frequent basis to identify deviations that have a strong likelihood of matching with a correctable tool condition. The tool matching methodology advantageously allows for monitoring of an automatically updated list of key parameters instead of needing to look at the full set of parameters collected from a control wafer each time. As such, tool matching can be performed on a more frequent basis.

Abstract: An imaging sensor assembly includes at least one substrate including a plurality of substrate signal lines. The imaging sensor assembly also includes at least one imaging sensor package disposed on the at least one substrate, the at least one imaging sensor package including at least one imaging sensor disposed on at least one imaging sensor package substrate. The imaging sensor assembly also includes at least one receiver package disposed on the at least one substrate, the receiver package including at least one receiver integrated circuit disposed on at least one receiver package substrate. The imaging sensor assembly also includes at least one electrical interconnect operably coupled to the at least one imaging sensor package and the at least one receiver package. A plurality of data signals are transmitted between the at least one imaging sensor package and the at least one receiver package via the at least one electrical interconnect.

Abstract: The present disclosure is directed to a system for inspecting a sample with multiple wavelengths of illumination simultaneously via parallel imaging paths. The system may include at least a first detector or set of detectors configured to detect illumination reflected, scattered, or radiated along a first imaging path from a selected portion of the sample in response to the first wavelength of illumination and a second detector or set of detectors configured to concurrently detect illumination reflected, scattered, or radiated along a second imaging path from the selected portion of the sample (i.e. the same location on the sample) in response to the second wavelength of illumination, where the second imaging path may at least partially share illumination and/or detection optics with an autofocus channel.

Abstract: A metrology system includes a controller coupled to a detector to generate a detection signal based on the reflection of an illumination beam from a multilayer film stack. The multilayer film stack may include one or more zones with a repeating pattern of two or more materials. The controller may generate a model of reflection of the illumination beam by modeling the zones as thick films having zone thicknesses and effective permittivity values using an effective medium model relating the effective permittivity values of the zones to permittivity values and volume fractions of constituent materials. The controller may further determine values of the zone thicknesses and the volume fractions using a regression of the detection signal based on the effective medium model and further determine average thickness values of the constituent materials based on the number of films, the zone thicknesses, the volume fractions, and the effective permittivity values.

Abstract: An inspection system/method in which first optics direct continuous wave (CW) light at 181-185 nm to an inspected article, and second optics redirect image information affected by the article to detectors. A laser assembly generates the CW light by generating fourth harmonic light from first fundamental CW light having a first wavelength between 1 and 1.1 ?m, generating fifth harmonic light by mixing the fourth harmonic light with the first fundamental CW light, and mixing the fifth harmonic light with second light having a second wavelength between 1.26 and 1.82 ?m. An external cavity mixes the first light and the fourth harmonic light using a first nonlinear crystal. The CW light is generated using a second cavity that passes circulated second fundamental or signal CW light through a second nonlinear crystal, and directing the fifth harmonic light through the second nonlinear crystal.

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: An inspection system includes an illumination sub-system, a collection sub-system, and a controller. The illumination sub-system includes an illumination source configured to generate a beam of illumination and a set of illumination optics to direct the beam of illumination to a sample. The collection sub-system includes a set of collection optics to collect illumination emanating from the sample and a detector configured to receive the collected illumination from the sample. The controller is configured to acquire a test image of the sample, reconstruct the test image to enhance the resolution of the test image, and detect one or more defects on the sample based on the reconstructed test image.

Abstract: Metrology methods and targets are provided, for estimating inter-cell process variation by deriving, from overlay measurements of at least three target cells having different designed misalignments, a dependency of a measured inaccuracy on the designed misalignments (each designed misalignment is between at least two overlapping periodic structures in the respective target cell). Inaccuracies which are related to the designed misalignments are reduced, process variation sources are detected and targets and measurement algorithms are optimized according to the derived dependency.

Abstract: Disclosed are apparatus and methods for performing overlay metrology upon a target having at least two layers formed thereon. A target having a plurality of periodic structures for measuring overlay in at least two overlay directions is provided. A charged particle beam is scanned in a first direction across a plurality of scan swaths of the target and at a first tilt with respect to the target so that each edge of the periodic structures is scanned at an angle. The charged particle beam is scanned in a second direction, which is opposite the first direction, across the plurality of scan swaths and at a second tilt that is 180° from the first tilt. The first and second direction scanning operations are then repeated for different first and second tilts and a different plurality of scan swaths of the target so that the target is scanned symmetrically.

Abstract: A process control system may include a controller configured to receive after-development inspection (ADI) data after a lithography step for the current layer from an ADI tool, receive after etch inspection (AEI) overlay data after an exposure step of the current layer from an AEI tool, train a non-zero offset predictor with ADI data and AEI overlay data to predict a non-zero offset from input ADI data, generate values of the control parameters of the lithography tool using ADI data and non-zero offsets generated by the non-zero offset predictor, and provide the values of the control parameters to the lithography tool for fabricating the current layer on the at least one production sample.

Abstract: Methods are provided, which estimate a quality of a metrology target by calculating a noise metric of its ROI kernels, derived from application of a Fourier filter on the measured kernel with respect to a periodicity of the target's periodic structure(s); and using the calculated noise metric to indicate the target quality. An additional Fourier filter may be applied perpendicularly on the measured kernel with respect to a periodicity of a perpendicular segmentation of the periodic structure(s), and the (2D) noise metric may be derived by application of both Fourier filters. The estimated noise may be analyzed statistically to provide various types of information on the target.

Abstract: The correlation of optical images with SEM images includes acquiring a full optical image of a sample by scanning the sample with an optical inspection sub-system, storing the full optical image, identifying a location of a feature-of-interest present in the full optical image with an additional sources, acquiring an SEM image of a portion of the sample that includes the feature at the identified location with a SEM tool, acquiring an optical image portion at the location identified by the additional source, the image portions including a reference structure, correlating the image portion and the SEM image based on the presence of the feature-of-interest and the reference structure in both the image portions and the SEM image, and transferring a location of the feature-of-interest in the SEM image into the coordinate system of the image portion of the full optical image to form a corrected optical image.

Abstract: Methods and systems for determining band structure characteristics of high-k dielectric films deposited over a substrate based on spectral response data are presented. High throughput spectrometers are utilized to quickly measure semiconductor wafers early in the manufacturing process. Optical models of semiconductor structures capable of accurate characterization of defects in high-K dielectric layers and embedded nanostructures are presented. In one example, the optical dispersion model includes a continuous Cody-Lorentz model having continuous first derivatives that is sensitive to a band gap of a layer of the unfinished, multi-layer semiconductor wafer. These models quickly and accurately represent experimental results in a physically meaningful manner. The model parameter values can be subsequently used to gain insight and control over a manufacturing process.

Abstract: An optical reticle inspection tool is used during a first inspection to obtain, for each set of one or more patch areas of the reticle, a reference average of multiple reference intensity values corresponding to light measured from sub-areas of each patch area. After using the reticle in photolithography processes, the optical reticle inspection tool is used during a second inspection to obtain, for each set of one or more patch areas, an average of multiple test intensity values corresponding to light measured from the sub-areas. The first and second inspections use the same tool setup recipe. A difference intensity map is generated, and such map comprises map values that each corresponds to a difference between each average of the test and reference intensity values for each set of one or more patches. The difference intensity map indicates whether the reticle has degraded over time more than a predefined level.