Patents Assigned to PDF Solutions, Inc.
  • Publication number: 20250138505
    Abstract: Wafer quality is determined by modeling equipment history as a sequence of events, then evaluating anomalous results for individual events. Identifying an event that generates bad wafers narrows the list of possible root causes.
    Type: Application
    Filed: December 27, 2024
    Publication date: May 1, 2025
    Applicant: PDF Solutions, Inc.
    Inventors: Tomonori Honda, Richard Burch, Jeffrey Drue David
  • Patent number: 12229945
    Abstract: A template for assigning the most probable root causes for wafer defects. The bin map data for a subject wafer can be compared with bin map data for prior wafers to find wafers with similar issues. A probability can be determined as to whether the same root cause should be applied to the subject wafer, and if so, the wafer can be labeled with that root cause accordingly.
    Type: Grant
    Filed: August 3, 2023
    Date of Patent: February 18, 2025
    Assignee: PDF Solutions, Inc.
    Inventors: Tomonori Honda, Lin Lee Cheong, Richard Burch, Qing Zhu, Jeffrey Drue David, Michael Keleher
  • Patent number: 12223012
    Abstract: A sequence of models accumulates r-squared values for an increasing number of variables in order to quantify the importance of each variable to the prediction of a targeted yield or parametric response.
    Type: Grant
    Filed: October 16, 2020
    Date of Patent: February 11, 2025
    Assignee: PDF Solutions, Inc.
    Inventors: Richard Burch, Qing Zhu, Jonathan Holt, Tomonori Honda
  • Publication number: 20240362106
    Abstract: A predictive model for equipment fail modes. An anomaly is detected in a collection of trace data, then key features are calculated. A search is conducted for the same or similar anomalies having the same key features in a database of past trace data. If the same anomaly occurred before and is in the database, then the type of anomaly, its root cause, and action steps to correct can be retrieved from the database.
    Type: Application
    Filed: April 29, 2023
    Publication date: October 31, 2024
    Applicant: PDF Solutions, Inc.
    Inventors: Richard Burch, Kazuki Kunitoshi
  • Patent number: 12038476
    Abstract: Systems, devices, and methods for performing a non-contact electrical measurement (NCEM) on a NCEM-enabled cell included in a NCEM-enabled cell vehicle may be configured to perform NCEMs while the NCEM-enabled cell vehicle is moving. The movement may be due to vibrations in the system and/or movement of a movable stage on which the NCEM-enabled cell vehicle is positioned. Position information for an electron beam column producing the electron beam performing the NCEMs and/or for the moving stage may be used to align the electron beam with targets on the NCEM-enabled cell vehicle while it is moving.
    Type: Grant
    Filed: May 5, 2023
    Date of Patent: July 16, 2024
    Assignee: PDF SOLUTIONS, INC.
    Inventors: Indranil De, Marian Mankos, Dennis Ciplickas, Christopher Hess, Jeremy Cheng, Balasubramanian Murugan, Qi Hu
  • Patent number: 12038802
    Abstract: Classifying wafers using Collaborative Learning. An initial wafer classification is determined by a rule-based model. A predicted wafer classification is determined by a machine learning model. Multiple users can manually review the classifications to confirm or modify, or to add user classifications. All of the classifications are input to the machine learning model to continuously update its scheme for detection and classification.
    Type: Grant
    Filed: October 14, 2020
    Date of Patent: July 16, 2024
    Assignee: PDF Solutions, Inc.
    Inventors: Tomonori Honda, Richard Burch, John Kibarian, Lin Lee Cheong, Qing Zhu, Vaishnavi Reddipalli, Kenneth Harris, Said Akar, Jeffrey D David, Michael Keleher, Brian Stine, Dennis Ciplickas
  • Patent number: 12020897
    Abstract: Systems, devices, and methods for performing a non-contact electrical measurement (NCEM) on a NCEM-enabled cell included in a NCEM-enabled cell vehicle may be configured to perform NCEMs while the NCEM-enabled cell vehicle is moving. The movement may be due to vibrations in the system and/or movement of a movable stage on which the NCEM-enabled cell vehicle is positioned. Position information for an electron beam column producing the electron beam performing the NCEMs and/or for the moving stage may be used to align the electron beam with targets on the NCEM-enabled cell vehicle while it is moving.
    Type: Grant
    Filed: February 11, 2023
    Date of Patent: June 25, 2024
    Assignee: PDF SOLUTIONS, INC.
    Inventors: Indranil De, Jeremy Cheng, Thomas Sokollik, Yoram Schwarz, Stephen Lam, Xumin Shen
  • Publication number: 20240184283
    Abstract: Detection of data anomalies resulting from maintenance activities on semiconductor processing equipment. Time-series representation of the key indicators for equipment performance is cleaned then segmented according to sharp breaks in the data. The cleaned and segmented data is modeled, for example, by determining a linear fit for each segment. The slope and intercept of each modeled segment linear fit are compared and evaluated to identify anomalies in the data.
    Type: Application
    Filed: December 1, 2023
    Publication date: June 6, 2024
    Applicant: PDF Solutions, Inc.
    Inventors: Tomonori Honda, Edward Zhou, Jeffrey D. David
  • Patent number: 11972987
    Abstract: A machine learning model for each die for imputing process control parameters at the die. The model is based on wafer sort parametric measurements at multiple test sites across the entire wafer, as well as yield results for the wafer. This allows for a better analysis of outlier spatial patterns leading to improved yield results.
    Type: Grant
    Filed: October 16, 2020
    Date of Patent: April 30, 2024
    Assignee: PDF Solutions, Inc.
    Inventors: Richard Burch, Qing Zhu, Jonathan Holt
  • Patent number: 11972552
    Abstract: A semiconductor image classifier. Convolution functions are applied to modify the wafer images in order to extract key information about the image. The modified images are condensed then processed through a series of pairwise classifiers, each classifier configured to determine that the image is more like one of the pair than the other. Probabilities from each classifier are collected to form a prediction for each image.
    Type: Grant
    Filed: April 22, 2021
    Date of Patent: April 30, 2024
    Assignee: PDF Solutions, Inc.
    Inventors: Tomonori Honda, Richard Burch, Qing Zhu, Jeffrey Drue David
  • Publication number: 20240127420
    Abstract: A method of evaluating the microstructure of a surface, such as a coating on a substrate. The surface is illuminated using at least one light source. One or more images of the illuminated surface are captured. The captured images are processed to identify one or more features of the microstructure, and then determine one or more parameters of the microstructure features. The parameters are compared to thresholds or limits to determine whether remedial action is needed.
    Type: Application
    Filed: October 16, 2023
    Publication date: April 18, 2024
    Applicant: PDF Solutions, Inc.
    Inventors: Peter Kostka, Jenna Slomowitz, Darcy Montgomery
  • Publication number: 20230377132
    Abstract: A template for assigning the most probable root causes for wafer defects. The bin map data for a subject wafer can be compared with bin map data for prior wafers to find wafers with similar issues. A probability can be determined as to whether the same root cause should be applied to the subject wafer, and if so, the wafer can be labeled with that root cause accordingly.
    Type: Application
    Filed: August 3, 2023
    Publication date: November 23, 2023
    Applicant: PDF Solutions, Inc.
    Inventors: Tomonori Honda, Lin Lee Cheong, Richard Burch, Qing Zhu, Jeffrey Drue David, Michael Keleher
  • Patent number: 11775714
    Abstract: A robust predictive model. A plurality of different predictive models for a target feature are run, and a comparative analysis provided for each predictive model that meet minimum performance criteria for the target feature. One of the predictive models is selected, either manually or automatically, based on predefined criteria. For semi-automatic selection, a static or dynamic survey is generated for obtaining user preferences for parameters associated with the target feature. The survey results will be used to generate a model that illustrates parameter trade-offs, which will be used to finalize the optimal predictive model for the user.
    Type: Grant
    Filed: June 4, 2021
    Date of Patent: October 3, 2023
    Assignee: PDF Solutions, Inc.
    Inventors: Tomonori Honda, Lin Lee Cheong, Lakshmikar Kuravi, Bogdan Cirlig
  • Patent number: 11763446
    Abstract: A template for assigning the most probable root causes for wafer defects. The bin map data for a subject wafer can be compared with bin map data for prior wafers to find wafers with similar issues. A probability can be determined as to whether the same root cause should be applied to the subject wafer, and if so, the wafer can be labeled with that root cause accordingly.
    Type: Grant
    Filed: April 30, 2021
    Date of Patent: September 19, 2023
    Assignee: PDF Solutions, Inc.
    Inventors: Tomonori Honda, Lin Lee Cheong, Richard Burch, Qing Zhu, Jeffrey Drue David, Michael Keleher
  • Patent number: 11687439
    Abstract: Automatic definition of windows for trace analysis. For each process step, the trace data are aligned to both the start of the process step and the end of the process step, and statistics including rate of change are calculated from both the start of the process step and the end of the process step. Windows are generated based on analysis of the calculated statistics.
    Type: Grant
    Filed: July 22, 2021
    Date of Patent: June 27, 2023
    Assignee: PDF Solutions, Inc.
    Inventors: Richard Burch, Kazuki Kunitoshi, Michio Aruga, Nobichika Akiya
  • Patent number: 11668746
    Abstract: Systems, devices, and methods for performing a non-contact electrical measurement (NCEM) on a NCEM-enabled cell included in a NCEM-enabled cell vehicle may be configured to perform NCEMs while the NCEM-enabled cell vehicle is moving. The movement may be due to vibrations in the system and/or movement of a movable stage on which the NCEM-enabled cell vehicle is positioned. Position information for an electron beam column producing the electron beam performing the NCEMs and/or for the moving stage may be used to align the electron beam with targets on the NCEM-enabled cell vehicle while it is moving.
    Type: Grant
    Filed: May 23, 2022
    Date of Patent: June 6, 2023
    Assignee: PDF SOLUTIONS, INC.
    Inventors: Indranil De, Marian Mankos, Dennis Ciplickas, Christopher Hess, Jeremy Cheng, Balasubramanian Murugan, Qi Hu
  • Patent number: 11640160
    Abstract: Enhancement of less dominant patterns for parametric wafer measurements. Dominant patterns are removed from the parametric pattern thereby revealing a less dominant pattern. The less dominant patterns can be used to identify root causes for yield loss that are not visible in the original parametric measurements.
    Type: Grant
    Filed: August 6, 2021
    Date of Patent: May 2, 2023
    Assignee: PDF Solutions, Inc.
    Inventors: Richard Burch, Qing Zhu
  • Patent number: 11640328
    Abstract: A predictive model for equipment fail modes. An anomaly is detected in a collection of trace data, then key features are calculated. A search is conducted for the same or similar anomalies having the same key features in a database of past trace data. If the same anomaly occurred before and is in the database, then the type of anomaly, its root cause, and action steps to correct can be retrieved from the database.
    Type: Grant
    Filed: July 22, 2021
    Date of Patent: May 2, 2023
    Assignee: PDF Solutions, Inc.
    Inventors: Richard Burch, Kazuki Kunitoshi
  • Patent number: 11609812
    Abstract: Scheme for detection and classification of semiconductor equipment faults. Sensor traces are monitored and processed to separate known abnormal operating conditions from unknown abnormal operating conditions. Feature engineering permits focus on relevant traces for a targeted feature. A machine learning model is built to detect and classify based on an initial classification set of anomalies. The machine learning model is continuously updated as more traces are processed and learned.
    Type: Grant
    Filed: October 6, 2020
    Date of Patent: March 21, 2023
    Assignee: PDF Solutions, Inc.
    Inventors: Richard Burch, Jeffrey D. David, Qing Zhu, Tomonori Honda, Lin Lee Cheong
  • Patent number: 11605526
    Abstract: Systems, devices, and methods for performing a non-contact electrical measurement (NCEM) on a NCEM-enabled cell included in a NCEM-enabled cell vehicle may be configured to perform NCEMs while the NCEM-enabled cell vehicle is moving. The movement may be due to vibrations in the system and/or movement of a movable stage on which the NCEM-enabled cell vehicle is positioned. Position information for an electron beam column producing the electron beam performing the NCEMs and/or for the moving stage may be used to align the electron beam with targets on the NCEM-enabled cell vehicle while it is moving.
    Type: Grant
    Filed: May 6, 2022
    Date of Patent: March 14, 2023
    Assignee: PDF SOLUTIONS, INC.
    Inventors: Indranil De, Jeremy Cheng, Thomas Sokollik, Yoram Schwarz, Stephen Lam, Xumin Shen