Patents Assigned to KLA-Tencor Corporation
  • Patent number: 10983227
    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.
    Type: Grant
    Filed: August 13, 2018
    Date of Patent: April 20, 2021
    Assignee: KLA-Tencor Corporation
    Inventors: John Hench, Antonio Arion Gellineau, Alexander Kuznetsov
  • Patent number: 10976249
    Abstract: Methods and systems for relaying an optical image using a cascade arrangement of tilted, concave mirrors are presented. An exemplary optical relay system includes a cascade arrangement of four mirrors each having concave, spherical surface figures. The first and third mirrors are configured to focus collimated wavefronts and the second and fourth mirrors re-collimate diverging wavefronts reflected from the first and third mirrors. Each mirror is tilted such that wavefronts located in the local field plane and local pupil plane of each mirror are physically separated. The magnitude and direction of each tilt angle are arranged such that off-axis aberrations introduced by each individual mirrors are largely compensated by the other mirrors. Such an optical relay system is employed to relay images of the pupil plane of a metrology system that is configured to perform accurate measurements of semiconductor structures and materials over a broad range of illumination wavelengths.
    Type: Grant
    Filed: October 1, 2014
    Date of Patent: April 13, 2021
    Assignee: KLA-Tencor Corporation
    Inventors: Andrew Hill, Gregory Brady
  • Patent number: 10970834
    Abstract: A deep learning algorithm is used for defect discovery, such as for semiconductor wafers. A care area is inspected with the wafer inspection tool. The deep learning algorithm is used to identify and classify defects in the care area. This can be repeated for remaining care areas, but similar care areas may be skipped to increase throughput.
    Type: Grant
    Filed: July 13, 2018
    Date of Patent: April 6, 2021
    Assignee: KLA-Tencor Corporation
    Inventor: Arpit Yati
  • Patent number: 10962951
    Abstract: Methods and metrology modules are provided, which derive landscape information (expressing relation(s) between metrology metric(s) and measurement parameters) from produced wafers, identifying therein indications for production process changes, and modify production process parameters with respect to the identified indications, to maintain the production process within specified requirements. Process changes may be detected in wafer(s), wafer lot(s) and batches, and the information may be used to detect root causes for the changes with respect to production tools and steps and to indicate tool aging and required maintenance. The information and its analysis may further be used to optimize the working point parameters, to optimizing designs of devices and/or targets and/or to train corresponding algorithms to perform the identifying, e.g., using training wafers.
    Type: Grant
    Filed: June 20, 2018
    Date of Patent: March 30, 2021
    Assignee: KLA-Tencor Corporation
    Inventors: Roie Volkovich, Yaniv Abramovitz
  • Patent number: 10964016
    Abstract: A best optical inspection mode to detect defects can be determined when no defect examples or only a limited number of defect examples are available. A signal for a defect of interest at the plurality of sites and for the plurality of modes can be determined using electromagnetic simulation. A ratio of the signal for the defect of interest to the noise at each combination of the plurality of sites and the plurality of modes can be determined. A mode with optimized signal-to-noise characteristics can be determined based on the ratios.
    Type: Grant
    Filed: March 7, 2019
    Date of Patent: March 30, 2021
    Assignee: KLA-Tencor Corporation
    Inventor: Bjorn Brauer
  • Patent number: 10964013
    Abstract: A system, method, and non-transitory computer readable medium are provided for training and applying defect classifiers in wafers having deeply stacked layers. In use, a plurality of images generated by an inspection system for a location of a defect detected on a wafer by the inspection system are acquired. The location on the wafer is comprised of a plurality of stacked layers, and each image of the plurality of images is generated by the inspection system at the location using a different focus setting. Further, a classification of the defect is determined, utilizing the plurality of images.
    Type: Grant
    Filed: January 5, 2018
    Date of Patent: March 30, 2021
    Assignee: KLA-TENCOR CORPORATION
    Inventors: Martin Plihal, Ankit Jain
  • Patent number: 10959318
    Abstract: Methods and systems for x-ray based semiconductor metrology utilizing a broadband, soft X-ray illumination source are described herein. A laser produced plasma (LPP) light source generates high brightness, broadband, soft x-ray illumination. The LPP light source directs a highly focused, short duration laser source to a non-metallic droplet target in a liquid or solid state. In one example, a droplet generator dispenses a sequence of nominally 50 micron droplets of feed material at a rate between 50 and 400 kilohertz. In one aspect, the duration of each pulse of excitation light is less than one nanosecond. In some embodiments, the duration of each pulse of excitation light is less than 0.5 nanoseconds. In some embodiments, the LPP light source includes a gas separation system that separates unspent feed material from other gases in the plasma chamber and provides the separated feed material back to the droplet generator.
    Type: Grant
    Filed: January 10, 2018
    Date of Patent: March 23, 2021
    Assignee: KLA-Tencor Corporation
    Inventors: Oleg Khodykin, Alexander Bykanov
  • Patent number: 10957608
    Abstract: A wafer topography measurement system can be paired with a scanning electron microscope. A topography threshold can be applied to wafer topography data about the wafer, which was obtained with the wafer topography measurement system. A metrology sampling plan can be generated for the wafer. This metrology sampling plan can include locations in the wafer topography data above the topography threshold. The scanning electron microscope can scan the wafer using the metrology sampling plan and identify defects.
    Type: Grant
    Filed: November 16, 2017
    Date of Patent: March 23, 2021
    Assignee: KLA-Tencor Corporation
    Inventors: Arpit Yati, Shivam Agarwal, Jagdish Saraswatula, Andrew Cross
  • Patent number: 10957033
    Abstract: Repeater defects on a wafer can be detected by fusing multiple die images. In an instance, multiple die images are statistically fused to form a die-fused image. Each of the die images can be of a different die on a wafer. A presence of a repeater defect is detected in the die-fused image. The die images can be generated using a laser-scanning system or other systems.
    Type: Grant
    Filed: September 14, 2017
    Date of Patent: March 23, 2021
    Assignee: KLA-Tencor Corporation
    Inventors: Premchandra M. Shankar, Ashok Varadarajan, JuHwan Rha
  • Patent number: 10957568
    Abstract: Disclosed are methods and apparatus for facilitating defect detection in a multilayer stack. The method includes selection of a set of structure parameters for modeling a particular multilayer stack and a particular defect contained within such particular multilayer stack and a set of operating parameters for an optical inspection system. Based on the set of structure and operating parameters, an electromagnetic simulation is performed of waves scattered from the particular multilayer stack and defect and arriving at a collection pupil of the optical inspection system.
    Type: Grant
    Filed: February 26, 2020
    Date of Patent: March 23, 2021
    Assignee: KLA-Tencor Corporation
    Inventors: Robert M. Danen, Dmitri G Starodub
  • Patent number: 10943838
    Abstract: A method and system for measuring overlay in a semiconductor manufacturing process comprise capturing an image of a feature in an article at a predetermined manufacturing stage, deriving a quantity of an image parameter from the image and converting the quantity into an overlay measurement. The conversion is by reference to an image parameter quantity derived from a reference image of a feature at the same predetermined manufacturing stage with known overlay (“OVL”). There is also disclosed a method of determining a device inspection recipe for use by an inspection tool comprising identifying device patterns as candidate device care areas that may be sensitive to OVL, deriving an OVL response for each identified pattern, correlating the OVL response with measured OVL, and selecting some or all of the device patterns as device care areas based on the correlation.
    Type: Grant
    Filed: June 24, 2018
    Date of Patent: March 9, 2021
    Assignee: KLA-Tencor Corporation
    Inventors: Choon Hoong Hoo, Fangren Ji, Amnon Manassen, Liran Yerushalmi, Antonio Mani, Allen Park, Stilian Pandev, Andrei Shchegrov, Jon Madsen
  • Patent number: 10935893
    Abstract: Disclosed are apparatus and methods for determining process or structure parameters for semiconductor structures. A plurality of optical signals is acquired from one or more targets located in a plurality of fields on a semiconductor wafer. The fields are associated with different process parameters for fabricating the one or more targets, and the acquired optical signals contain information regarding a parameter of interest (POI) for a top structure and information regarding one or more underlayer parameters for one or more underlayers formed below such top structure. A feature extraction model is generated to extract a plurality of feature signals from such acquired optical signals so that the feature signals contain information for the POI and exclude information for the underlayer parameters. A POI value for each top structure of each field is determined based on the feature signals extracted by the feature extraction model.
    Type: Grant
    Filed: August 6, 2014
    Date of Patent: March 2, 2021
    Assignee: KLA-Tencor Corporation
    Inventors: Stilian Ivanov Pandev, Andrei V. Shchegrov
  • Patent number: 10928739
    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.
    Type: Grant
    Filed: April 12, 2019
    Date of Patent: February 23, 2021
    Assignee: KLA-Tencor Corporation
    Inventors: Roie Volkovich, Ido Dolev
  • Patent number: 10930597
    Abstract: Embodiments herein include methods, systems, and apparatuses for die screening using inline defect information. Such embodiments may include receiving a plurality of defects, receiving wafersort electrical data for a plurality of dies, classifying each of the defects as a defect-of-interest or nuisance, determining a defect-of-interest confidence for each of the defects-of-interest, determining a die return index for each of the dies containing at least one of the defects-of-interest, determining a die return index cutline, and generating an inking map. Each of the defects may be associated with a die in the plurality of dies. Each of the dies may be tagged as passing a wafersort electrical test or failing the wafersort electrical test. Classifying each of the defects as a defect-of-interest or nuisance may be accomplished using a defect classification model, which may include machine learning. The inking map may be electronically communicated to an inking system.
    Type: Grant
    Filed: June 12, 2019
    Date of Patent: February 23, 2021
    Assignee: KLA-Tencor Corporation
    Inventors: Alex Teng Song Lim, Ganesh Meenakshisundaram
  • Patent number: 10921262
    Abstract: Disclosed are apparatus and methods for inspecting a sample. Locations corresponding to candidate defect events on a sample are provided from an inspector operable to acquire optical images from which such candidate defect events are detected at their corresponding locations across the sample. High-resolution images are acquired from a high-resolution inspector of the candidate defect events at their corresponding locations on the sample. Each of a set of modelled optical images, which have been modeled from a set of the acquired high-resolution images, is correlated with corresponding ones of a set of the acquired optical images, to identify surface noise events, as shown in the set of high-resolution images, as sources for the corresponding candidate events in the set of acquired optical images. Otherwise, a subsurface event is identified as a likely source for a corresponding candidate defect event.
    Type: Grant
    Filed: May 28, 2020
    Date of Patent: February 16, 2021
    Assignee: KLA-Tencor Corporation
    Inventors: Qiang Zhang, Grace H. Chen
  • Patent number: 10916462
    Abstract: A method of focusing includes irradiating an object by directing radiation output by a radiating source through an objective lens, measuring a first intensity of reflected radiation that is reflected from the object, adjusting a distance between the objective lens and the object, measuring a second intensity of reflected radiation, and analyzing the first intensity of reflected radiation and the second intensity of reflected radiation to determine a focal distance between the objective lens and the object. The distance between the objective lens and the object is adjusted to the focal distance and the irradiating intensity is increased to mark the object. In another example, measuring the first intensity of reflected radiation is performed by directing reflected radiation from the object through the objective lens, a beam splitter, a focusing lens, and a pinhole and onto a sensor that outputs a signal indicative of sensed radiation intensity.
    Type: Grant
    Filed: August 9, 2018
    Date of Patent: February 9, 2021
    Assignee: KLA-TENCOR CORPORATION
    Inventors: Timothy Russin, Shiyu Zhang, Charles Amsden, Daniel Kapp
  • Patent number: 10901325
    Abstract: Methods are provided for designing metrology targets and estimating the uncertainty error of metrology metric values with respect to stochastic noise such as line properties (e.g., line edge roughness, LER). Minimal required dimensions of target elements may be derived from analysis of the line properties and uncertainty error of metrology measurements, by either CDSEM (critical dimension scanning electron microscopy) or optical systems, with corresponding targets. The importance of this analysis is emphasized in view of the finding that stochastic noise may have increased importance with when using more localized models such as CPE (correctables per exposure). The uncertainty error estimation may be used for target design, enhancement of overlay estimation and evaluation of measurement reliability in multiple contexts.
    Type: Grant
    Filed: February 27, 2018
    Date of Patent: January 26, 2021
    Assignee: KLA-Tencor Corporation
    Inventors: Evgeni Gurevich, Michael E. Adel, Roel Gronheid, Yoel Feler, Vladimir Levinski, Dana Klein, Sharon Aharon
  • Patent number: 10902579
    Abstract: Defects of interest can be captured by a classifier. Images of a semiconductor wafer can be received at a deep learning classification module. These images can be sorted into soft decisions with the deep learning classification module. A class of the defect of interest for an image can be determined from the soft decisions. The deep learning classification module can be in electronic communication with an optical inspection system or other types of semiconductor inspection systems.
    Type: Grant
    Filed: November 13, 2018
    Date of Patent: January 26, 2021
    Assignee: KLA-Tencor Corporation
    Inventors: Erfan Soltanmohammadi, Martin Plihal, Tai-Kam Ng, Sang Hyun Lee
  • Patent number: 10897566
    Abstract: Focusing methods and modules are provided for metrology tools and systems. Methods comprise capturing image(s) of at least two layers of a ROI in an imaging target, binning the captured image(s), deriving a focus shift from the binned captured image(s) by comparing the layers, and calculating a focus position from the derived focus shift. Disclosed methods are direct, may be carried out in parallel to a part of the overlay measurement process and provide fast and simple focus measurements that improve metrology performance.
    Type: Grant
    Filed: August 25, 2017
    Date of Patent: January 19, 2021
    Assignee: KLA-Tencor Corporation
    Inventors: Nadav Gutman, Boris Golovanevsky, Noam Gluzer
  • Patent number: 10895541
    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.
    Type: Grant
    Filed: December 21, 2018
    Date of Patent: January 19, 2021
    Assignee: KLA-Tencor Corporation
    Inventors: Andrei V. Shchegrov, Alexander Kuznetsov, Oleg Khodykin