Patents by Inventor Kaushik Sah

Kaushik Sah 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).

  • Publication number: 20230175983
    Abstract: Process window qualification (PWQ) layouts can be used to determine a presence of a pattern anomaly associated with the pattern, patterning process, or patterning apparatus. For example, a modulated die or field can be compared to a slightly lower offset modulated die or field. In another example, the high to low corners for a particular condition or combination of conditions are compared. In yet another example, process modulation parameters can be used to estimate criticality of particular weak points of interest.
    Type: Application
    Filed: April 26, 2022
    Publication date: June 8, 2023
    Inventors: Andrew CROSS, Kaushik SAH, Martin PLIHAL
  • Publication number: 20220270212
    Abstract: A system and method for enhancing image quality. The system and method acquire a machine learning model trained for correlating one or more training images and one or more training design images. The system and method receive one or more sample specimen images corresponding to one or more features of a sample specimen. The system and method enhance the one or more sample specimen images by generating one or more enhanced images with the machine learning model based on at least the one or more sample specimen images.
    Type: Application
    Filed: February 16, 2022
    Publication date: August 25, 2022
    Inventors: Kaushik Sah, Thirupurasundari Jayaraman, Srikanth Kandukuri, Andrew James Cross, Gangadharan Sivaraman
  • Publication number: 20220244648
    Abstract: A characterization system for inspecting or performing metrology on a layer within a semiconductor stack is disclosed. The system includes an imaging sub-system configured to acquire image data from a semiconductor stack including one or more layers. The semiconductor stack includes a metal layer having a thickness between 0.5 and 10 nm deposited on a layer of the semiconductor stack to form a reflective surface on the layer. The system includes a controller. The controller is configured to receive image data of the reflective surface on the layer of the substrate stack and identify one or more defects or one or more structures within the layer based on illumination reflected from the reflective surface.
    Type: Application
    Filed: February 4, 2021
    Publication date: August 4, 2022
    Inventors: Kaushik Sah, Andrew James Cross, Sandip Halder, Sayantan Das
  • Patent number: 10818001
    Abstract: A stochastic calculation engine receives inputs from a semiconductor inspection tool or semiconductor review tool. The stochastic calculation engine determines abnormal locations and pattern variation from the inputs and determines stochastic failures from the inputs. An electronic data storage unit connected with the stochastic calculation engine can include a database with known stochastic behavior and known process metrology variations. The stochastic calculation engine can flag stochastic features, determine a failure rate, or determine fail probability.
    Type: Grant
    Filed: January 7, 2019
    Date of Patent: October 27, 2020
    Assignee: KLA-Tencor Corporation
    Inventors: Wing-Shan Ribi Leung, Kaushik Sah, Allen Park, Andrew Cross
  • Patent number: 10699926
    Abstract: Methods and systems fir identifying nuisances and defects of interest (DOIs) in defects detected on a wafer are provided. One method includes acquiring metrology data for the wafer generated by a metrology tool that performs measurements on the wafer at an array of measurement points. In one embodiment, the measurement points are determined prior to detecting the defects on the wafer and independently of the defects detected on the wafer. The method also includes determining locations of defects detected on the wafer with respect to locations of the measurement points on the wafer and assigning metrology data to the defects as a defect attribute based on the locations of the defects determined with respect to the locations of the measurement points. In addition, the method includes determining if the defects are nuisances or DOIs based on the defect attributes assigned to the defects.
    Type: Grant
    Filed: August 27, 2018
    Date of Patent: June 30, 2020
    Assignee: KLA-Tencor Corp.
    Inventors: Martin Plihal, Brian Duffy, Mike VonDenHoff, Andrew Cross, Kaushik Sah, Antonio Mani
  • Patent number: 10598617
    Abstract: Information from metrology tools can be used during inspection or review with a scanning electron microscope. Metrology measurements of a wafer are interpolated and/or extrapolated over a field, which creates modified metrology data. The modified metrology data is associated with defect attributes from inspection measurements of a wafer. A wafer review sampling plan is generated based on the defect attributes and the modified metrology data. The wafer review sampling plan can be used during review of a wafer using the scanning electron microscope.
    Type: Grant
    Filed: August 8, 2017
    Date of Patent: March 24, 2020
    Assignee: KLA-Tencor Corporation
    Inventors: Kaushik Sah, Andrew James Cross, Antonio Mani
  • Publication number: 20200082523
    Abstract: A stochastic calculation engine receives inputs from a semiconductor inspection tool or semiconductor review tool. The stochastic calculation engine determines abnormal locations and pattern variation from the inputs and determines stochastic failures from the inputs. An electronic data storage unit connected with the stochastic calculation engine can include a database with known stochastic behavior and known process metrology variations. The stochastic calculation engine can flag stochastic features, determine a failure rate, or determine fail probability.
    Type: Application
    Filed: January 7, 2019
    Publication date: March 12, 2020
    Inventors: Wing-Shan Ribi Leung, Kaushik Sah, Allen Park, Andrew Cross
  • Patent number: 10540759
    Abstract: Wafer edge profile images are analyzed at locations around a bonded wafer, which may have a top wafer and a carrier wafer. An offset curve is generated based on the wafer edge profile images. Displacement of the top wafer to the carrier wafer is determined based on the offset curve. The wafer edge profile images may be generated at multiple locations around the wafer. The wafer edge profile images may be shadowgram images. A system to determine displacement of the top wafer to the carrier wafer can include an imaging system connected with a controller.
    Type: Grant
    Filed: June 20, 2017
    Date of Patent: January 21, 2020
    Assignee: KLA-Tencor Corporation
    Inventors: Kaushik Sah, Thomas Krah, Shifang Li, Heiko Eisenbach, Moritz Stoerring
  • Publication number: 20190067060
    Abstract: Methods and systems fir identifying nuisances and defects of interest (DOIs) in defects detected on a wafer are provided. One method includes acquiring metrology data for the wafer generated by a metrology tool that performs measurements on the wafer at an array of measurement points. In one embodiment, the measurement points are determined prior to detecting the defects on the wafer and independently of the defects detected on the wafer. The method also includes determining locations of defects detected on the wafer with respect to locations of the measurement points on the wafer and assigning metrology data to the defects as a defect attribute based on the locations of the defects determined with respect to the locations of the measurement points. In addition, the method includes determining if the defects are nuisances or DOIs based on the defect attributes assigned to the defects.
    Type: Application
    Filed: August 27, 2018
    Publication date: February 28, 2019
    Inventors: Martin Plihal, Brian Duffy, Mike VonDenHoff, Andrew Cross, Kaushik Sah, Antonio Mani
  • Publication number: 20180321168
    Abstract: Information from metrology tools can be used during inspection or review with a scanning electron microscope. Metrology measurements of a wafer are interpolated and/or extrapolated over a field, which creates modified metrology data. The modified metrology data is associated with defect attributes from inspection measurements of a wafer. A wafer review sampling plan is generated based on the defect attributes and the modified metrology data. The wafer review sampling plan can be used during review of a wafer using the scanning electron microscope.
    Type: Application
    Filed: August 8, 2017
    Publication date: November 8, 2018
    Inventors: Kaushik Sah, Andrew James Cross, Antonio Mani
  • Patent number: 10068323
    Abstract: A design aware system, method, and computer program product are provided for detecting overlay-related defects in multi-patterned fabricated devices. In use, a design of a multi-patterned fabricated device is received by a computer system. Then, the computer system automatically determines from the design one or more areas of the design that are prone to causing overlay errors. Further, an indication of the determined one or more areas is output by the computer system to an inspection system for use in inspecting a multi-patterned device fabricated in accordance with the design.
    Type: Grant
    Filed: October 11, 2016
    Date of Patent: September 4, 2018
    Assignee: KLA-TENCOR CORPORATION
    Inventors: Kaushik Sah, Andrew James Cross
  • Publication number: 20180150952
    Abstract: Wafer edge profile images are analyzed at locations around a bonded wafer, which may have a top wafer and a carrier wafer. An offset curve is generated based on the wafer edge profile images. Displacement of the top wafer to the carrier wafer is determined based on the offset curve. The wafer edge profile images may be generated at multiple locations around the wafer. The wafer edge profile images may be shadowgram images. A system to determine displacement of the top wafer to the carrier wafer can include an imaging system connected with a controller.
    Type: Application
    Filed: June 20, 2017
    Publication date: May 31, 2018
    Inventors: Kaushik Sah, Thomas Krah, Shifang Li, Heiko Eisenbach, Moritz Stoerring
  • Publication number: 20170294012
    Abstract: A design aware system, method, and computer program product are provided for detecting overlay-related defects in multi-patterned fabricated devices. In use, a design of a multi-patterned fabricated device is received by a computer system. Then, the computer system automatically determines from the design one or more areas of the design that are prone to causing overlay errors. Further, an indication of the determined one or more areas is output by the computer system to an inspection system for use in inspecting a multi-patterned device fabricated in accordance with the design.
    Type: Application
    Filed: October 11, 2016
    Publication date: October 12, 2017
    Inventors: Kaushik Sah, Andrew James Cross