Patents by Inventor Pradeep Vukkadala

Pradeep Vukkadala 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: 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: 9779202
    Abstract: Systems and methods to detect, quantify, and control process-induced asymmetric signatures using patterned wafer geometry measurements are disclosed. The system may include a geometry measurement tool configured to obtain a first set of wafer geometry measurements of the wafer prior to the wafer undergoing a fabrication process and to obtain a second set of wafer geometry measurements of the wafer after the fabrication process. The system may also include a processor in communication with the geometry measurement tool. The processor may be configured to: calculate a geometry-change map based on the first set of wafer geometry measurements and the second set of wafer geometry measurements; analyze the geometry-change map to detect an asymmetric component induced to wafer geometry by the fabrication process; and estimate an asymmetric overlay error induced by the fabrication process based on the asymmetric component detected in wafer geometry.
    Type: Grant
    Filed: September 28, 2015
    Date of Patent: October 3, 2017
    Assignee: KLA-Tencor Corporation
    Inventors: Pradeep Vukkadala, Jaydeep Sinha, Jong-Hoon Kim
  • Patent number: 9707660
    Abstract: Predictive modeling based focus error prediction method and system are disclosed. The method includes obtaining wafer geometry measurements of a plurality of training wafers and grouping the plurality of training wafers to provide at least one training group based on relative homogeneity of wafer geometry measurements among the plurality of training wafers. For each particular training group of the at least one training group, a predictive model is develop utilizing non-linear predictive modeling. The predictive model establishes correlations between wafer geometry parameters and focus error measurements obtained for each wafer within that particular training group, and the predictive model can be utilized to provide focus error prediction for an incoming wafer belonging to that particular training group.
    Type: Grant
    Filed: August 12, 2014
    Date of Patent: July 18, 2017
    Assignee: KLA-Tencor Corporation
    Inventors: Pradeep Vukkadala, Jaydeep Sinha, Wei Chang, Krishna Rao
  • 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: 20160371423
    Abstract: Systems and methods to detect, quantify, and control process-induced asymmetric signatures using patterned wafer geometry measurements are disclosed. The system may include a geometry measurement tool configured to obtain a first set of wafer geometry measurements of the wafer prior to the wafer undergoing a fabrication process and to obtain a second set of wafer geometry measurements of the wafer after the fabrication process. The system may also include a processor in communication with the geometry measurement tool. The processor may be configured to: calculate a geometry-change map based on the first set of wafer geometry measurements and the second set of wafer geometry measurements; analyze the geometry-change map to detect an asymmetric component induced to wafer geometry by the fabrication process; and estimate an asymmetric overlay error induced by the fabrication process based on the asymmetric component detected in wafer geometry.
    Type: Application
    Filed: September 28, 2015
    Publication date: December 22, 2016
    Inventors: Pradeep Vukkadala, Jaydeep Sinha, Jong-Hoon Kim
  • 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: 20160239600
    Abstract: Prediction based systems and methods for optimizing wafer chucking and lithography control are disclosed. Distortions predicted to occur when a wafer is chucked by a chucking device are calculated and are utilized to control chucking parameters of the chucking device. Chucking parameters may include chucking pressures and chucking sequences. In addition, predicted distortions may also be utilized to facilitate application of anticipatory corrections. Controlling chucking parameters and/or applying anticipatory corrections help reducing or minimizing overlay errors.
    Type: Application
    Filed: March 12, 2015
    Publication date: August 18, 2016
    Inventors: Bin-Ming Benjamin Tsai, Oreste Donzella, Pradeep Vukkadala, Jaydeep Sinha
  • Patent number: 9373165
    Abstract: Methods and systems enabling ultra-high resolution topography measurements of patterned wafers are disclosed. Measurements obtained utilizing the ultra-high resolution metrology may be utilized to improve wafer metrology measurement accuracies. Additionally, measurements obtained utilizing the ultra-high resolution metrology may also be utilized to provide feedback and/or calibration control to improve fabrication and design of wafers.
    Type: Grant
    Filed: October 22, 2014
    Date of Patent: June 21, 2016
    Assignee: KLA-Tencor Corporation
    Inventors: Amir Azordegan, Pradeep Vukkadala, Craig MacNaughton, Jaydeep Sinha
  • 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: 20160071260
    Abstract: Methods and systems enabling ultra-high resolution topography measurements of patterned wafers are disclosed. Measurements obtained utilizing the ultra-high resolution metrology may be utilized to improve wafer metrology measurement accuracies. Additionally, measurements obtained utilizing the ultra-high resolution metrology may also be utilized to provide feedback and/or calibration control to improve fabrication and design of wafers.
    Type: Application
    Filed: October 22, 2014
    Publication date: March 10, 2016
    Inventors: Amir Azordegan, Pradeep Vukkadala, Craig MacNaughton, Jaydeep Sinha
  • Patent number: 9177370
    Abstract: Systems and methods for providing micro defect inspection capabilities for optical systems are disclosed. Each given wafer image is filtered, treated and normalized prior to performing surface feature detection and quantification. A partitioning scheme is utilized to partition the wafer image into a plurality of measurement sites and metric values are calculated for each of the plurality of measurement sites. Furthermore, transformation steps may also be utilized to extract additional process relevant metric values for analysis purposes.
    Type: Grant
    Filed: February 28, 2013
    Date of Patent: November 3, 2015
    Assignee: KLA-Tencor Corporation
    Inventors: Haiguang Chen, Sergey Kamensky, Jaydeep Sinha, Pradeep Vukkadala
  • Publication number: 20150298282
    Abstract: Wafer geometry measurement tools and methods for providing improved wafer geometry measurements are disclosed. Wafer front side, backside and flatness measurements are taken into consideration for semiconductor process control. The measurement tools and methods in accordance with embodiments of the present disclosure are suitable for handling any types of wafers, including patterned wafers, without the shortcomings of conventional metrology systems.
    Type: Application
    Filed: June 24, 2014
    Publication date: October 22, 2015
    Inventors: Pradeep Vukkadala, Jaydeep Sinha
  • Publication number: 20150302312
    Abstract: Predictive modeling based focus error prediction method and system are disclosed. The method includes obtaining wafer geometry measurements of a plurality of training wafers and grouping the plurality of training wafers to provide at least one training group based on relative homogeneity of wafer geometry measurements among the plurality of training wafers. For each particular training group of the at least one training group, a predictive model is develop utilizing non-linear predictive modeling. The predictive model establishes correlations between wafer geometry parameters and focus error measurements obtained for each wafer within that particular training group, and the predictive model can be utilized to provide focus error prediction for an incoming wafer belonging to that particular training group.
    Type: Application
    Filed: August 12, 2014
    Publication date: October 22, 2015
    Inventors: Pradeep Vukkadala, Jaydeep Sinha, Wei Chang, Krishna Rao
  • 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: 9052190
    Abstract: A method of providing high accuracy inspection or metrology in a bright-field differential interference contrast (BF-DIC) system is described. This method can include creating first and second beams from a first light beam. The first and second beams have round cross-sections, and form first partially overlapping scanning spots radially displaced on a substrate. Third and fourth beams are created from the first light beam or a second light beam. The third and fourth beams have elliptical cross-sections, and form second partially overlapping scanning spots tangentially displaced on the substrate. At least one portion of the substrate can be scanned using the first and second partially overlapping scanning spots as the substrate is rotated. Radial and tangential slopes can be determined using measurements obtained from the scanning using the first and second partially overlapping scanning spots. These slopes can be used to determine wafer shape or any localized topography feature.
    Type: Grant
    Filed: March 12, 2013
    Date of Patent: June 9, 2015
    Assignee: KLA-Tencor Corporation
    Inventors: Ali Salehpour, Jaydeep Sinha, Kurt Lindsay Haller, Pradeep Vukkadala, George Kren, Jiayao Zhang, Mehdi Vaez-Iravani