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.
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:
Application
Filed:
July 22, 2021
Publication date:
January 27, 2022
Applicant:
PDF Solutions, Inc.
Inventors:
Richard Burch, Kazuki Kunitoshi, Michio Aruga, Nobichika Akiya
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.
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:
April 30, 2021
Publication date:
November 4, 2021
Applicant:
PDF Solutions, Inc.
Inventors:
Tomonori Honda, Lin Lee Cheong, Richard Burch, Qing Zhu, Jeffrey Drue David, Michael Keleher
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:
Application
Filed:
April 22, 2021
Publication date:
October 28, 2021
Applicant:
PDF Solutions, Inc.
Inventors:
Tomonori Honda, Richard Burch, Qing Zhu, Jeffrey Drue David
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:
Application
Filed:
June 4, 2021
Publication date:
September 23, 2021
Applicant:
PDF Solutions, Inc.
Inventors:
Tomonori Honda, Lin Lee Cheong, Lakshmikar Kuravi, Bogdan Cirlin
Abstract: 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.
Abstract: An IC that includes a contiguous standard cell area with a 4x3 e-beam pad that is compatible with advanced manufacturing processes and an associated e-beam testable structure.
Type:
Grant
Filed:
June 30, 2019
Date of Patent:
August 31, 2021
Assignee:
PDF Solutions, Inc.
Inventors:
Stephen Lam, Dennis Ciplickas, Tomasz Brozek, Jeremy Cheng, Simone Comensoli, Indranil De, Kelvin Doong, Hans Eisenmann, Timothy Fiscus, Jonathan Haigh, Christopher Hess, John Kibarian, Sherry Lee, Marci Liao, Sheng-Che Lin, Hideki Matsuhashi, Kimon Michaels, Conor O'Sullivan, Markus Rauscher, Vyacheslav Rovner, Andrzej Strojwas, Marcin Strojwas, Carl Taylor, Rakesh Vallishayee, Larg Weiland, Nobuharu Yokoyama, Matthew Moe
Abstract: An IC that includes a contiguous standard cell area with a 4×3 e-beam pad that is compatible with advanced manufacturing processes and an associated e-beam testable structure.
Type:
Grant
Filed:
June 30, 2019
Date of Patent:
August 3, 2021
Assignee:
PDF Solutions, Inc.
Inventors:
Stephen Lam, Dennis Ciplickas, Tomasz Brozek, Jeremy Cheng, Simone Comensoli, Indranil De, Kelvin Doong, Hans Eisenmann, Timothy Fiscus, Jonathan Haigh, Christopher Hess, John Kibarian, Sherry Lee, Marci Liao, Sheng-Che Lin, Hideki Matsuhashi, Kimon Michaels, Conor O'Sullivan, Markus Rauscher, Vyacheslav Rovner, Andrzej Strojwas, Marcin Strojwas, Carl Taylor, Rakesh Vallishayee, Larg Weiland, Nobuharu Yokoyama, Matthew Moe
Abstract: An IC that includes a contiguous standard cell area with a 4×3 e-beam pad that is compatible with advanced manufacturing processes and an associated e-beam testable structure.
Type:
Grant
Filed:
June 30, 2019
Date of Patent:
August 3, 2021
Assignee:
PDF Solutions, Inc.
Inventors:
Stephen Lam, Dennis Ciplickas, Tomasz Brozek, Jeremy Cheng, Simone Comensoli, Indranil De, Kelvin Doong, Hans Eisenmann, Timothy Fiscus, Jonathan Haigh, Christopher Hess, John Kibarian, Sherry Lee, Marci Liao, Sheng-Che Lin, Hideki Matsuhashi, Kimon Michaels, Conor O'Sullivan, Markus Rauscher, Vyacheslav Rovner, Andrzej Strojwas, Marcin Strojwas, Carl Taylor, Rakesh Vallishayee, Larg Weiland, Nobuharu Yokoyama, Matthew Moe
Abstract: An IC that includes a contiguous standard cell area with a 4×3 e-beam pad that is compatible with advanced manufacturing processes and an associated e-beam testable structure.
Type:
Grant
Filed:
June 30, 2019
Date of Patent:
July 27, 2021
Assignee:
PDF Solutions, Inc.
Inventors:
Stephen Lam, Dennis Ciplickas, Tomasz Brozek, Jeremy Cheng, Simone Comensoli, Indranil De, Kelvin Doong, Hans Eisenmann, Timothy Fiscus, Jonathan Haigh, Christopher Hess, John Kibarian, Sherry Lee, Marci Liao, Sheng-Che Lin, Hideki Matsuhashi, Kimon Michaels, Conor O'Sullivan, Markus Rauscher, Vyacheslav Rovner, Andrzej Strojwas, Marcin Strojwas, Carl Taylor, Rakesh Vallishayee, Larg Weiland, Nobuharu Yokoyama, Matthew Moe
Abstract: A model is generated for predicting failures at the wafer production level. Input data from sensors is stored as an initial dataset, then data exhibiting excursions or useless impact is removed from the dataset. The dataset is converted into target features, where the target features are useful in predicting whether a wafer will be normal or not. A trade-off between positive and negative results is selected, and a plurality of predictive models are created. The final model is selected based on the trade-off criteria, and deployed.
Type:
Grant
Filed:
March 8, 2019
Date of Patent:
June 8, 2021
Assignee:
PDF Solutions, Inc.
Inventors:
Tomonori Honda, Lin Lee Cheong, Lakshmikar Kuravi
Abstract: Robust machine learning predictions. Temporal dependencies of process targets for different machine learning models can be captured and evaluated for the impact on process performance for target. The most robust of these different models is selected for deployment based on minimizing variance for the desired performance characteristic.
Type:
Grant
Filed:
June 12, 2018
Date of Patent:
June 8, 2021
Assignee:
PDF Solutions, Inc.
Inventors:
Tomonori Honda, Rohan D. Kekatpure, Jeffrey Drue David
Abstract: A method for predicting yield for a semiconductor process. A particular type of wafer is fabricated to have a first set of features disposed on the wafer, with a wafer map identifying a location for each of the first set of features on the wafer. Data from wafer acceptance tests and circuit probe tests is collected over time for wafers of that particular type as made in a semiconductor fabrication process, and at least one training dataset and a least one validation dataset are created from the collected data. A second set of “engineered” features are created and also incorporated onto the wafer and wafer map. Important features from the first and second sets of features are identified and selected, and using those important features as inputs, a number of different process models are run, with yield as the target. The results of the different models can be combined, for example, statistically.
Type:
Grant
Filed:
August 24, 2018
Date of Patent:
June 1, 2021
Assignee:
PDF Solutions, Inc.
Inventors:
Jeffrey Drue David, Tomonori Honda, Lin Lee Cheong
Abstract: An IC that includes a contiguous standard cell area with a 4×3 e-beam pad that is compatible with advanced manufacturing processes and an associated e-beam testable structure.
Type:
Grant
Filed:
June 30, 2019
Date of Patent:
May 25, 2021
Assignee:
PDF Solutions, Inc.
Inventors:
Stephen Lam, Dennis Ciplickas, Tomasz Brozek, Jeremy Cheng, Simone Comensoli, Indranil De, Kelvin Doong, Hans Eisenmann, Timothy Fiscus, Jonathan Haigh, Christopher Hess, John Kibarian, Sherry Lee, Marci Liao, Sheng-Che Lin, Hideki Matsuhashi, Kimon Michaels, Conor O'Sullivan, Markus Rauscher, Vyacheslav Rovner, Andrzej Strojwas, Marcin Strojwas, Carl Taylor, Rakesh Vallishayee, Larg Weiland, Nobuharu Yokoyama, Matthew Moe
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:
Application
Filed:
October 14, 2020
Publication date:
May 13, 2021
Applicant:
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 Stein, Dennis Ciplickas
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:
Application
Filed:
October 16, 2020
Publication date:
April 22, 2021
Applicant:
PDF Solutions, Inc.
Inventors:
Richard Burch, Qing Zhu, Jonathan Holt, Tomonori Honda
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.
Abstract: An IC that includes a contiguous standard cell area with a 4×3 e-beam pad that is compatible with advanced manufacturing processes and an associated e-beam testable structure.
Type:
Grant
Filed:
June 29, 2019
Date of Patent:
April 13, 2021
Assignee:
PDF Solutions, Inc.
Inventors:
Stephen Lam, Dennis Ciplickas, Tomasz Brozek, Jeremy Cheng, Simone Comensoli, Indranil De, Kelvin Doong, Hans Eisenmann, Timothy Fiscus, Jonathan Haigh, Christopher Hess, John Kibarian, Sherry Lee, Marci Liao, Sheng-Che Lin, Hideki Matsuhashi, Kimon Michaels, Conor O'Sullivan, Markus Rauscher, Vyacheslav Rovner, Andrzej Strojwas, Marcin Strojwas, Carl Taylor, Rakesh Vallishayee, Larg Weiland, Nobuharu Yokoyama, Matthew Moe
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:
Application
Filed:
October 6, 2020
Publication date:
April 8, 2021
Applicant:
PDF Solutions, Inc.
Inventors:
Richard Burch, Jeffrey D. David, Qing Zhu, Tomonori Honda, Lin Lee Cheong