Abstract: A method of measuring misregistration in the manufacture of semiconductor devices including providing a multilayered semiconductor device, using a scatterometry metrology tool to perform misregistration measurements at multiple sites on the multilayered semiconductor device, receiving raw misregistration data for each of the misregistration measurements, thereafter providing filtered misregistration data by removing outlying raw misregistration data points from the raw misregistration data for each of the misregistration measurements, using the filtered misregistration data to model misregistration for the multilayered semiconductor device, calculating correctables from the modeled misregistration for the multilayered semiconductor device, providing the correctables to the scatterometry metrology tool, thereafter recalibrating the scatterometry metrology tool based on the correctables and measuring misregistration using the scatterometry metrology tool following the recalibration.

Abstract: Defects from a hot scan can be saved, such as on persistent storage, random access memory, or a split database. The persistent storage can be patch-based virtual inspector virtual analyzer (VIVA) or local storage. Repeater defect detection jobs can determined and the wafer can be inspected based on the repeater defect detection jobs. Repeater defects can be analyzed and corresponding defect records to the repeater defects can be read from the persistent storage. These results may be returned to the high level defect detection controller.

Abstract: Methods and systems for combining information present in measured images of semiconductor wafers with additional measurements of particular structures within the measured images are presented herein. In one aspect, an image-based signal response metrology (SRM) model is trained based on measured images and corresponding reference measurements of particular structures within each image. The trained, image-based SRM model is then used to calculate values of one or more parameters of interest directly from measured image data collected from other wafers. In another aspect, a measurement signal synthesis model is trained based on measured images and corresponding measurement signals generated by measurements of particular structures within each image by a non-imaging measurement technique.

Abstract: Techniques and systems to achieve more accurate design alignment to an image by improved pixel-to-design alignment (PDA) target selection are disclosed. PDA targets in an image frame of a die can be biased to include a hotspot location in one of the PDA targets. The PDA targets can be evaluated for repetitive patterns by analyzing the uniqueness of the points used as the PDA targets.

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: A method of determining overlay (“OVL”) in a pattern in a semiconductor wafer manufacturing process comprises capturing images from a cell in a metrology target formed in at least two different layers in the wafer with parts of the target offset in opposing directions with respect to corresponding parts in a different layer. The images may be captured using radiation of multiple different wavelengths, each image including +1 and ?1 diffraction patterns. A first and second differential signal may be determined for respective pixels in each image by subtracting opposing pixels from the +1 and ?1 diffraction orders for each of the multiple wavelengths. An OVL for the respective pixels may be determined based on analyzing the differential signals from multiple wavelengths simultaneously. Then an OVL for the pattern may be determined as a weighted average of the OVL of the respective pixels.

Abstract: Common events between layers on a semiconductor wafer are filtered. Common events should contain the majority of defects of interest. Only nuisance events that are common between layers on the semiconductor wafer remain, which reduces the nuisance rate. Defects that are common across layers can be filtered based on, for example, defect coordinates, a difference image, or defect attributes.

Abstract: Methods and systems for estimating values of process parameters, structural parameters, or both, based on x-ray scatterometry measurements of high aspect ratio semiconductor structures are presented herein. X-ray scatterometry measurements are performed at one or more steps of a fabrication process flow. The measurements are performed quickly and with sufficient accuracy to enable yield improvement of an on-going semiconductor fabrication process flow. Process corrections are determined based on the measured values of parameters of interest and the corrections are communicated to the process tool to change one or more process control parameters of the process tool. In some examples, measurements are performed while the wafer is being processed to control the on-going fabrication process step. In some examples, X-ray scatterometry measurements are performed after a particular process step and process control parameters are updated for processing of future devices.

Abstract: Metrology targets, design methods and measurement methods thereof are provided with periodic structure(s) which are oblique with respect to orthogonal production axes X and Y of the lithography tool—enabling more accurate overlay measurements of devices having diagonal (oblique, tilted) elements such as DRAM devices. One or more oblique periodic structure(s) may be used to provide one- or two-dimensional signals, with respect to one or more layers, possibly providing overlay measurements for multiple steps applied to one layer. The oblique periodic structure(s) may be used to modify current metrology target designs (e.g., imaging targets and/or scatterometry targets) or to design new targets, and measurement algorithms may be adjusted respectively to derive signals from the oblique periodic structure(s) and/or to provide pre-processed images thereof. The disclosed targets are process compatible and reflect more accurately the device overlays with respect to various process steps.

Abstract: A system, method, and non-transitory computer readable medium are provided for tuning sensitivities of, and determining a process window for, a modulated wafer. The sensitivities for dies of the modulated wafer are tuned dynamically based on a single set of parameters. Further, the process window is determined for the modulated wafer from prior determined parameter-specific nominal process windows.

Abstract: Methods and systems for enhanced defect detection based on images collected by at least two imaging detectors at different times are described. In some embodiments, the time between image measurements is at least 100 microseconds and no more than 10 milliseconds. In one aspect, one or more defects of interest are identified based on a composite image of a measured area generated based on a difference between collected images. In a further aspect, measurement conditions associated with the each imaged location are adjusted to be different for measurements performed by at least two imaging detectors at different times. In some embodiments, the measurement conditions are adjusted during the time between measurements by different imaging detectors. Exemplary changes of measurement conditions include environmental changes at the wafer under measurement and changes made to the optical configuration of the inspection system.

Abstract: In one embodiment, disclosed are apparatus, methods, and targets for determining a phase shift of a photomask having a phase-shift target. An inspection or metrology system is used to direct an incident beam towards the target and then detect a plurality of intensity measurements that are transmitted through the target in response to the incident beam. A phase shift value for the target may then be determined based on the intensity measurements.

Abstract: Disclosed are methods and apparatus for hermetically sealing a nonlinear optical (NLO) crystal for use in a laser system. A mounted NLO crystal, an enclosure base, a lid, and a plurality of window components are moved into an oven. A vacuum bake process is then performed on the mounted NLO crystal, enclosure base, lid, and plurality of window components until a humidity level that is less than a predefined amount is reached. The mounted NLO crystal, enclosure base, lid, and plurality of window components are moved from the oven onto a stage of a glove box that includes a sealing tool. In the glove box, the mounted NLO crystal is hermetically sealed into the enclosure base by sealing the lid and plurality of window components into openings of the enclosure base.

Abstract: Defect location accuracy can be increased using shape based grouping with pattern-based defect centering. Design based grouping of defects on a wafer can be performed. A spatial distribution of the defects around at least one structure on the wafer, such as a predicted hot spot, can be determined. At least one design based defect property for a location around the structure can be determined. The defects within an x-direction threshold and a y-direction threshold of the structure may be prioritized.

Abstract: A target for use in the optical measurement of misregistration in the manufacture of semiconductor devices, the target including a first periodic structure formed on a first layer of a semiconductor device and having a first pitch along an axis and a second periodic structure formed on a second layer of the semiconductor device and having a second pitch along the axis, different from the first pitch, the second periodic structure extending beyond the first periodic structure along the axis.

Abstract: Scatterometry overlay targets as well as target design and measurement methods are provided, which mitigate the effects of grating asymmetries in diffraction based overlay measurements. Targets comprise additional cells with sub-resolved structures replacing resolved coarse pitch gratings and/or comprise alternating sub-resolved structures with coarse pitch periodicity—to isolate and remove inaccuracies that result from grating asymmetries. Measurement methods utilize orthogonally polarized illumination to isolate the grating asymmetry effects in different measurement directions, with respect to the designed target structures.

Abstract: Designs for a hybrid overlay target design that includes a target area with both an imaging-based target and a scatterometry-based target are disclosed. The imaging-based overlay target design can include side-by-side grating structure. A scatterometry-based overlay target design at a different location in the target area can include grating-over-grating structure. A method of measuring the hybrid overlay target design and a system with both an imaging optical system and a scatterometry system for measuring the hybrid overlay target design are also disclosed.

Abstract: An image sensor for electrons or short-wavelength light includes a semiconductor membrane, circuit elements formed on one surface of the semiconductor membrane, and a pure boron layer on the other surface of the semiconductor membrane. The circuit elements are connected by metal interconnects comprising a refractory metal. An anti-reflection or protective layer may be formed on top of the pure boron layer. This image sensor has high efficiency and good stability even under continuous use at high flux for multiple years. The image sensor may be fabricated using CCD (charge coupled device) or CMOS (complementary metal oxide semiconductor) technology. The image sensor may be a two-dimensional area sensor, or a one-dimensional array sensor.

Abstract: Methods and systems for solving measurement models of complex device structures with reduced computational effort and memory requirements are presented. The computational efficiency of electromagnetic simulation algorithms based on truncated spatial harmonic series is improved for periodic targets that exhibit a fundamental spatial period and one or more approximate periods that are integer fractions of the fundamental spatial period. Spatial harmonics are classified according to each distinct period of the target exhibiting multiple periodicity. A distinct truncation order is selected for each group of spatial harmonics. This approach produces optimal, sparse truncation order sampling patterns, and ensures that only harmonics with significant contributions to the approximation of the target are selected for computation.

Abstract: Systems and methods to focus and align multiple electron beams are disclosed. A camera produces image data of light from electron beams that is projected at a fiber optics array with multiple targets. An image processing module determines an adjustment to a voltage applied to a relay lens, a field lens, or a multi-pole array based on the image data. The adjustment minimizes at least one of a displacement, a defocus, or an aberration of one of the electron beams. Using a control module, the voltage is applied to the relay lens, the field lens, or the multi-pole array.