Patents by Inventor Sathish Veeraraghavan

Sathish Veeraraghavan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11761880
    Abstract: Systems and methods for prediction and measurement of overlay errors are disclosed. Process-induced overlay errors may be predicted or measured utilizing film force based computational mechanics models. More specifically, information with respect to the distribution of film force is provided to a finite element (FE) model to provide more accurate point-by-point predictions in cases where complex stress patterns are present. Enhanced prediction and measurement of wafer geometry induced overlay errors are also disclosed.
    Type: Grant
    Filed: August 5, 2019
    Date of Patent: September 19, 2023
    Assignee: KLA Corporation
    Inventors: Pradeep Vukkadala, Haiguang Chen, Jaydeep K. Sinha, Sathish Veeraraghavan
  • Patent number: 10509329
    Abstract: Systems and methods for providing improved measurements and predictions of geometry induced overlay errors are disclosed. Information regarding variations of overlay errors is obtained and analyzed to improve semiconductor processes as well as lithography patterning. In some embodiments, a cascading analysis process is utilized to breakdown the wafer geometry induced overlay into various components. The breakdown analysis may also be utilized to determine effectiveness factors for the various components, which in turn may improve the prediction accuracy of the impact of wafer geometry on wafer overlay. Furthermore, the measurements and/or predictions of the wafer geometry induced overlay errors may be utilized to provide overlay monitoring and correction solutions.
    Type: Grant
    Filed: January 14, 2015
    Date of Patent: December 17, 2019
    Assignee: KLA-Tencor Corporation
    Inventors: Sathish Veeraraghavan, Chin-Chou Huang
  • Publication number: 20190353582
    Abstract: Systems and methods for prediction and measurement of overlay errors are disclosed. Process-induced overlay errors may be predicted or measured utilizing film force based computational mechanics models. More specifically, information with respect to the distribution of film force is provided to a finite element (FE) model to provide more accurate point-by-point predictions in cases where complex stress patterns are present. Enhanced prediction and measurement of wafer geometry induced overlay errors are also disclosed.
    Type: Application
    Filed: August 5, 2019
    Publication date: November 21, 2019
    Inventors: Pradeep Vukkadala, Haiguang Chen, Jaydeep K. Sinha, Sathish Veeraraghavan
  • Publication number: 20190271654
    Abstract: Systems and methods for improving results of wafer higher order shape (HOS) characterization and wafer classification are disclosed. The systems and methods in accordance with the present disclosure are based on localized shapes. A wafer map is partitioned into a plurality of measurement sites to improve the completeness of wafer shape representation. Various site based HOS metric values may be calculated for wafer characterization and/or classification purposes, and may also be utilized as control input for a downstream application. In addition, polar grid partitioning schemes are provided. Such polar grid partitioning schemes may be utilized to partition a wafer surface into measurement sites having uniform site areas while providing good wafer edge region coverage.
    Type: Application
    Filed: January 15, 2017
    Publication date: September 5, 2019
    Inventors: Haiguang Chen, Jaydeep Sinha, Sergey Kamensky, Sathish Veeraraghavan, Pradeep Vukkadala
  • Patent number: 10401279
    Abstract: Systems and methods for prediction and measurement of overlay errors are disclosed. Process-induced overlay errors may be predicted or measured utilizing film force based computational mechanics models. More specifically, information with respect to the distribution of film force is provided to a finite element (FE) model to provide more accurate point-by-point predictions in cases where complex stress patterns are present. Enhanced prediction and measurement of wafer geometry induced overlay errors are also disclosed.
    Type: Grant
    Filed: September 18, 2014
    Date of Patent: September 3, 2019
    Assignee: KLA-Tencor Corporation
    Inventors: Pradeep Vukkadala, Haiguang Chen, Jaydeep Sinha, Sathish Veeraraghavan
  • Patent number: 10379061
    Abstract: Systems and methods for improving results of wafer higher order shape (HOS) characterization and wafer classification are disclosed. The systems and methods in accordance with the present disclosure are based on localized shapes. A wafer map is partitioned into a plurality of measurement sites to improve the completeness of wafer shape representation. Various site based HOS metric values may be calculated for wafer characterization and/or classification purposes, and may also be utilized as control input for a downstream application. In addition, polar grid partitioning schemes are provided. Such polar grid partitioning schemes may be utilized to partition a wafer surface into measurement sites having uniform site areas while providing good wafer edge region coverage.
    Type: Grant
    Filed: January 15, 2017
    Date of Patent: August 13, 2019
    Assignee: KLA-Tencor Corporation
    Inventors: Haiguang Chen, Jaydeep Sinha, Sergey Kamensky, Sathish Veeraraghavan, Pradeep Vukkadala
  • Patent number: 10249523
    Abstract: The present invention may include acquiring a wafer shape value at a plurality of points of a wafer surface at a first and second process level, generating a wafer shape change value at each of the points, generating a set of slope of shape change values at each of the points, calculating a set of process tool correctables utilizing the generated set of slope of shape change values, generating a set of slope shape change residuals (SSCRs) by calculating a slope of shape change residual value at each of the points utilizing the set of process tool correctables, defining a plurality of metric analysis regions distributed across the surface, and then generating one or more residual slope shape change metrics for each metric analysis region based on one or more SSCRs within each metric analysis region.
    Type: Grant
    Filed: April 21, 2016
    Date of Patent: April 2, 2019
    Assignee: KLA-Tencor Corporation
    Inventors: Pradeep Vukkadala, Sathish Veeraraghavan, Jaydeep K. Sinha
  • Patent number: 10025894
    Abstract: Systems and methods for prediction of in-plane distortions (IPD) due to wafer shape in semiconductor wafer chucking process is disclosed. A series of Zernike basis wafer shapes process to emulate the non-linear finite element (FE) contact mechanics model based IPD prediction is utilized in accordance with one embodiment of the present disclosure. The emulated FE model based prediction process is substantially more efficient and provides accuracy comparable to the FE model based IPD prediction that utilizes full-scale 3-D wafer and chuck geometry information and requires computation intensive simulations. Furthermore, an enhanced HOS IPD/OPD prediction process based on a series of Zernike basis wafer shape images is also disclosed.
    Type: Grant
    Filed: June 3, 2016
    Date of Patent: July 17, 2018
    Assignee: KLA-Tencor Corporation
    Inventors: Pradeep Vukkadala, Sathish Veeraraghavan, Jaydeep Sinha, Haiguang Chen, Michael Kirk
  • Patent number: 9865047
    Abstract: Systems and methods for providing improved wafer geometry measurements are disclosed. A wafer geometry measurement system may utilize techniques that enable the wafer geometry measurement system to identify and reduce wafer surface errors caused by structures such as patterns on the wafers being measured. The wafer geometry measurement system may also utilize techniques that enable the wafer geometry measurement system to accurately reconstruct patterned wafer surfaces.
    Type: Grant
    Filed: October 15, 2015
    Date of Patent: January 9, 2018
    Assignee: KLA-Tencor Corporation
    Inventors: Haiguang Chen, Jaydeep Sinha, Enrique Chavez, Sathish Veeraraghavan
  • Patent number: 9558545
    Abstract: Systems and methods for predicting and controlling pattern quality data (e.g., critical dimension and/or pattern defectivity) in patterned wafers using patterned wafer geometry (PWG) measurements are disclosed. Correlations between PWG measurements and pattern quality data measurements may be established, and the established correlations may be utilized to provide pattern quality data predictions for a given wafer based on geometry measurements obtained for the give wafer. The predictions produced may be provided to a lithography tool, which may utilize the predictions to correct focus and/or title errors that may occur during the lithography process.
    Type: Grant
    Filed: June 4, 2015
    Date of Patent: January 31, 2017
    Assignee: KLA-Tencor Corporation
    Inventors: Pradeep Vukkadala, Sathish Veeraraghavan, Soham Dey, Jaydeep Sinha
  • Patent number: 9546862
    Abstract: Systems and methods for improving results of wafer higher order shape (HOS) characterization and wafer classification are disclosed. The systems and methods in accordance with the present disclosure are based on localized shapes. A wafer map is partitioned into a plurality of measurement sites to improve the completeness of wafer shape representation. Various site based HOS metric values may be calculated for wafer characterization and/or classification purposes, and may also be utilized as control input for a downstream application. In addition, polar grid partitioning schemes are provided. Such polar grid partitioning schemes may be utilized to partition a wafer surface into measurement sites having uniform site areas while providing good wafer edge region coverage.
    Type: Grant
    Filed: October 19, 2012
    Date of Patent: January 17, 2017
    Assignee: KLA-Tencor Corporation
    Inventors: Haiguang Chen, Jaydeep Sinha, Sergey Kamensky, Sathish Veeraraghavan, Pradeep Vukkadala
  • Publication number: 20160372353
    Abstract: The present invention may include acquiring a wafer shape value at a plurality of points of a wafer surface at a first and second process level, generating a wafer shape change value at each of the points, generating a set of slope of shape change values at each of the points, calculating a set of process tool correctables utilizing the generated set of slope of shape change values, generating a set of slope shape change residuals (SSCRs) by calculating a slope of shape change residual value at each of the points utilizing the set of process tool correctables, defining a plurality of metric analysis regions distributed across the surface, and then generating one or more residual slope shape change metrics for each metric analysis region based on one or more SSCRs within each metric analysis region.
    Type: Application
    Filed: April 21, 2016
    Publication date: December 22, 2016
    Inventors: Pradeep Vukkadala, Sathish Veeraraghavan, Jaydeep K. Sinha
  • Patent number: 9513565
    Abstract: Systems and methods for providing improved scanner corrections are disclosed. Scanner corrections provided in accordance with the present disclosure may be referred to as wafer geometry aware scanner corrections. More specifically, wafer geometry and/or wafer shape signature information are utilized to improve scanner corrections. By removing the wafer geometry as one of the error sources that may affect the overlay accuracy, better scanner corrections can be obtained because one less contributing factor needs to be modeled.
    Type: Grant
    Filed: April 10, 2015
    Date of Patent: December 6, 2016
    Assignee: KLA-Tencor Corporation
    Inventors: Craig MacNaughton, Sathish Veeraraghavan, Pradeep Vukkadala, Jaydeep Sinha, Amir Azordegan
  • Publication number: 20160283625
    Abstract: Systems and methods for prediction of in-plane distortions (IPD) due to wafer shape in semiconductor wafer chucking process is disclosed. A series of Zernike basis wafer shapes process to emulate the non-linear finite element (FE) contact mechanics model based IPD prediction is utilized in accordance with one embodiment of the present disclosure. The emulated FE model based prediction process is substantially more efficient and provides accuracy comparable to the FE model based IPD prediction that utilizes full-scale 3-D wafer and chuck geometry information and requires computation intensive simulations. Furthermore, an enhanced HOS IPD/OPD prediction process based on a series of Zernike basis wafer shape images is also disclosed.
    Type: Application
    Filed: June 3, 2016
    Publication date: September 29, 2016
    Inventors: Pradeep Vukkadala, Sathish Veeraraghavan, Jaydeep Sinha, Haiguang Chen, Michael Kirk
  • Patent number: 9430593
    Abstract: Systems and methods for prediction of in-plane distortions (IPD) due to wafer shape in semiconductor wafer chucking process is disclosed. A process to emulate the non-linear finite element (FE) contact mechanics model based IPD prediction is utilized in accordance with one embodiment of the present disclosure. The emulated FE model based prediction process is substantially more efficient and provides accuracy comparable to the FE model based IPD prediction that utilizes full-scale 3-D wafer and chuck geometry information and requires computation intensive simulations. Furthermore, an enhanced HOS IPD/OPD prediction process based on a series of Zernike basis wafer shape images is also disclosed.
    Type: Grant
    Filed: January 7, 2013
    Date of Patent: August 30, 2016
    Assignee: KLA-Tencor Corporation
    Inventors: Pradeep Vukkadala, Sathish Veeraraghavan, Jaydeep Sinha, Haiguang Chen, Michael Kirk
  • Publication number: 20160163033
    Abstract: Systems and methods for predicting and controlling pattern quality data (e.g., critical dimension and/or pattern defectivity) in patterned wafers using patterned wafer geometry (PWG) measurements are disclosed. Correlations between PWG measurements and pattern quality data measurements may be established, and the established correlations may be utilized to provide pattern quality data predictions for a given wafer based on geometry measurements obtained for the give wafer. The predictions produced may be provided to a lithography tool, which may utilize the predictions to correct focus and/or title errors that may occur during the lithography process.
    Type: Application
    Filed: June 4, 2015
    Publication date: June 9, 2016
    Inventors: Pradeep Vukkadala, Sathish Veeraraghavan, Soham Dey, Jaydeep Sinha
  • Patent number: 9354526
    Abstract: The present invention may include acquiring a wafer shape value at a plurality of points of a wafer surface at a first and second process level, generating a wafer shape change value at each of the points, generating a set of slope of shape change values at each of the points, calculating a set of process tool correctables utilizing the generated set of slope of shape change values, generating a set of slope shape change residuals (SSCRs) by calculating a slope of shape change residual value at each of the points utilizing the set of process tool correctables, defining a plurality of metric analysis regions distributed across the surface, and then generating one or more residual slope shape change metrics for each metric analysis region based on one or more SSCRs within each metric analysis region.
    Type: Grant
    Filed: May 21, 2012
    Date of Patent: May 31, 2016
    Assignee: KLA-Tencor Corporation
    Inventors: Pradeep Vukkadala, Sathish Veeraraghavan, Jaydeep K. Sinha
  • Publication number: 20160062252
    Abstract: Systems and methods for providing improved measurements and predictions of geometry induced overlay errors are disclosed. Information regarding variations of overlay errors is obtained and analyzed to improve semiconductor processes as well as lithography patterning. In some embodiments, a cascading analysis process is utilized to breakdown the wafer geometry induced overlay into various components. The breakdown analysis may also be utilized to determine effectiveness factors for the various components, which in turn may improve the prediction accuracy of the impact of wafer geometry on wafer overlay. Furthermore, the measurements and/or predictions of the wafer geometry induced overlay errors may be utilized to provide overlay monitoring and correction solutions.
    Type: Application
    Filed: January 14, 2015
    Publication date: March 3, 2016
    Inventors: Sathish Veeraraghavan, Chin-Chou Huang
  • Publication number: 20150212429
    Abstract: Systems and methods for providing improved scanner corrections are disclosed. Scanner corrections provided in accordance with the present disclosure may be referred to as wafer geometry aware scanner corrections. More specifically, wafer geometry and/or wafer shape signature information are utilized to improve scanner corrections. By removing the wafer geometry as one of the error sources that may affect the overlay accuracy, better scanner corrections can be obtained because one less contributing factor needs to be modeled.
    Type: Application
    Filed: April 10, 2015
    Publication date: July 30, 2015
    Inventors: Craig MacNaughton, Sathish Veeraraghavan, Pradeep Vukkadala, Jaydeep Sinha, Amir Azordegan
  • Patent number: 9029810
    Abstract: Systems and methods for providing improved scanner corrections are disclosed. Scanner corrections provided in accordance with the present disclosure may be referred to as wafer geometry aware scanner corrections. More specifically, wafer geometry and/or wafer shape signature information are utilized to improve scanner corrections. By removing the wafer geometry as one of the error sources that may affect the overlay accuracy, better scanner corrections can be obtained because one less contributing factor needs to be modeled.
    Type: Grant
    Filed: May 27, 2014
    Date of Patent: May 12, 2015
    Assignee: KLA-Tencor Corporation
    Inventors: Craig MacNaughton, Sathish Veeraraghavan, Pradeep Vukkadala, Jaydeep Sinha, Amir Azordegan