Patents Assigned to PDF Solutions, Inc.
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Publication number: 20250138505Abstract: 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: ApplicationFiled: December 27, 2024Publication date: May 1, 2025Applicant: PDF Solutions, Inc.Inventors: Tomonori Honda, Richard Burch, Jeffrey Drue David
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Patent number: 12229945Abstract: 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: GrantFiled: August 3, 2023Date of Patent: February 18, 2025Assignee: PDF Solutions, Inc.Inventors: Tomonori Honda, Lin Lee Cheong, Richard Burch, Qing Zhu, Jeffrey Drue David, Michael Keleher
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Patent number: 12223012Abstract: 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: GrantFiled: October 16, 2020Date of Patent: February 11, 2025Assignee: PDF Solutions, Inc.Inventors: Richard Burch, Qing Zhu, Jonathan Holt, Tomonori Honda
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Publication number: 20240362106Abstract: 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: ApplicationFiled: April 29, 2023Publication date: October 31, 2024Applicant: PDF Solutions, Inc.Inventors: Richard Burch, Kazuki Kunitoshi
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Patent number: 12038802Abstract: 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: GrantFiled: October 14, 2020Date of Patent: July 16, 2024Assignee: 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
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Publication number: 20240184283Abstract: 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: ApplicationFiled: December 1, 2023Publication date: June 6, 2024Applicant: PDF Solutions, Inc.Inventors: Tomonori Honda, Edward Zhou, Jeffrey D. David
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Patent number: 11972552Abstract: 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: GrantFiled: April 22, 2021Date of Patent: April 30, 2024Assignee: PDF Solutions, Inc.Inventors: Tomonori Honda, Richard Burch, Qing Zhu, Jeffrey Drue David
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Patent number: 11972987Abstract: 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: GrantFiled: October 16, 2020Date of Patent: April 30, 2024Assignee: PDF Solutions, Inc.Inventors: Richard Burch, Qing Zhu, Jonathan Holt
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Publication number: 20240127420Abstract: 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: ApplicationFiled: October 16, 2023Publication date: April 18, 2024Applicant: PDF Solutions, Inc.Inventors: Peter Kostka, Jenna Slomowitz, Darcy Montgomery
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Publication number: 20230377132Abstract: 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: ApplicationFiled: August 3, 2023Publication date: November 23, 2023Applicant: PDF Solutions, Inc.Inventors: Tomonori Honda, Lin Lee Cheong, Richard Burch, Qing Zhu, Jeffrey Drue David, Michael Keleher
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Patent number: 11775714Abstract: 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: GrantFiled: June 4, 2021Date of Patent: October 3, 2023Assignee: PDF Solutions, Inc.Inventors: Tomonori Honda, Lin Lee Cheong, Lakshmikar Kuravi, Bogdan Cirlig
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Patent number: 11763446Abstract: 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: GrantFiled: April 30, 2021Date of Patent: September 19, 2023Assignee: PDF Solutions, Inc.Inventors: Tomonori Honda, Lin Lee Cheong, Richard Burch, Qing Zhu, Jeffrey Drue David, Michael Keleher
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Patent number: 11687439Abstract: 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: GrantFiled: July 22, 2021Date of Patent: June 27, 2023Assignee: PDF Solutions, Inc.Inventors: Richard Burch, Kazuki Kunitoshi, Michio Aruga, Nobichika Akiya
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Patent number: 11640328Abstract: 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: GrantFiled: July 22, 2021Date of Patent: May 2, 2023Assignee: PDF Solutions, Inc.Inventors: Richard Burch, Kazuki Kunitoshi
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Patent number: 11640160Abstract: 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: GrantFiled: August 6, 2021Date of Patent: May 2, 2023Assignee: PDF Solutions, Inc.Inventors: Richard Burch, Qing Zhu
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Patent number: 11609812Abstract: 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: GrantFiled: October 6, 2020Date of Patent: March 21, 2023Assignee: PDF Solutions, Inc.Inventors: Richard Burch, Jeffrey D. David, Qing Zhu, Tomonori Honda, Lin Lee Cheong
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Publication number: 20220327268Abstract: 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: ApplicationFiled: June 4, 2021Publication date: October 13, 2022Applicant: PDF Solutions, Inc.Inventors: Tomonori Honda, Lin Lee Cheong, Lakshmikar Kuravi, Bogdan Cirlin
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Patent number: 11328108Abstract: Semiconductor yield is modeled at the die level to predict die that are susceptible to early lifetime failure (ELF). A first die yield calculation is made from parametric data obtained from wafer testing in a semiconductor manufacturing process. A second die yield calculation is made from die location only. The difference between the first die yield calculation and the second die yield calculation is a prediction delta. Based on an evaluation of the first die yield calculation and the prediction delta, the likelihood of early lifetime failure can be identified and an acceptable level of die loss can be established to remove die from further processing.Type: GrantFiled: March 2, 2021Date of Patent: May 10, 2022Assignee: PDF Solutions, Inc.Inventors: Richard Burch, Qing Zhu, Keith Arnold
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Patent number: 11295993Abstract: A maintenance tool for semiconductor process equipment and components. Sensor data is evaluated by machine learning tools to determine when to schedule maintenance action.Type: GrantFiled: August 25, 2020Date of Patent: April 5, 2022Assignee: PDF Solutions, Inc.Inventors: Tomonori Honda, Jeffrey Drue David, Lin Lee Cheong
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Publication number: 20220066410Abstract: 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: ApplicationFiled: August 27, 2021Publication date: March 3, 2022Applicant: PDF Solutions, Inc.Inventors: Tomonori Honda, Richard Burch, Jeffrey Drue David