Patents by Inventor Mahendra Dubey

Mahendra Dubey 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: 11880142
    Abstract: A self-calibrating overlay metrology system may receive device overlay data for a device targets on a sample from an overlay metrology tool, determine preliminary device overlay measurements for the device targets including device-scale features using an overlay recipe with the device overlay data as inputs, receive assist overlay data for one or more assist targets on the sample including device-scale features from the overlay metrology tool, where at least one of the one or more assist targets has a programmed overlay offset of a selected value along a particular measurement direction, determine self-calibrating assist overlay measurements for the one or more assist targets based on the assist overlay data, where the self-calibrating assist overlay measurements are linearly proportional to overlay on the sample, and generate corrected overlay measurements for the device targets by adjusting the preliminary device overlay measurements based on the self-calibrating assist overlay measurements.
    Type: Grant
    Filed: March 7, 2023
    Date of Patent: January 23, 2024
    Assignee: KLA Corporation
    Inventors: Stilian Pandev, Min-Yeong Moon, Andrei V. Shchegrov, Jonathan Madsen, Dimitry Sanko, Liran Yerushalmi, Alexander Kuznetsov, Mahendra Dubey
  • Publication number: 20230221656
    Abstract: A self-calibrating overlay metrology system may receive device overlay data for a device targets on a sample from an overlay metrology tool, determine preliminary device overlay measurements for the device targets including device-scale features using an overlay recipe with the device overlay data as inputs, receive assist overlay data for one or more assist targets on the sample including device-scale features from the overlay metrology tool, where at least one of the one or more assist targets has a programmed overlay offset of a selected value along a particular measurement direction, determine self-calibrating assist overlay measurements for the one or more assist targets based on the assist overlay data, where the self-calibrating assist overlay measurements are linearly proportional to overlay on the sample, and generate corrected overlay measurements for the device targets by adjusting the preliminary device overlay measurements based on the self-calibrating assist overlay measurements.
    Type: Application
    Filed: March 7, 2023
    Publication date: July 13, 2023
    Inventors: Stilian Pandev, Min-Yeong Moon, Andrei V. Shchegrov, Jonathan Madsen, Dimitry Sanko, Liran Yerushalmi, Alexander Kuznetsov, Mahendra Dubey
  • Patent number: 11604420
    Abstract: A self-calibrating overlay metrology system may receive device overlay data from device targets on a sample, determine preliminary device overlay measurements for the device targets including device-scale features using an overlay recipe with the device overlay data as inputs, receive assist overlay data from sets of assist targets on the sample including device-scale features, where a particular set of assist targets includes one or more target pairs formed with two overlay targets having programmed overlay offsets of a selected value with opposite signs along a particular measurement direction.
    Type: Grant
    Filed: September 28, 2021
    Date of Patent: March 14, 2023
    Assignee: KLA Corporation
    Inventors: Stilian Pandev, Min-Yeong Moon, Andrei V. Shchegrov, Jonathan Madsen, Dimitry Sanko, Liran Yerushalmi, Alexander Kuznetsov, Mahendra Dubey
  • Patent number: 11604063
    Abstract: An overlay metrology system may receive overlay data for in-die overlay targets within various fields on a skew training sample from one or more overlay metrology tools, wherein the in-die overlay targets within the fields have a range programmed overlay offsets, wherein the fields are fabricated with a range of programmed skew offsets. The system may further generate asymmetric target signals for the in-die overlay targets using an asymmetric function providing a value of zero when physical overlay is zero and a sign indicative of a direction of physical overlay. The system may further generate corrected overlay offsets for the in-die overlay targets on the asymmetric target signals, generate self-calibrated overlay offsets for the in-die overlay targets based on the programmed overlay offsets and the corrected overlay offsets, generate a trained overlay recipe, and generate overlay measurements for in-die overlay targets on additional samples using the trained overlay recipe.
    Type: Grant
    Filed: September 13, 2021
    Date of Patent: March 14, 2023
    Assignee: KLA Corporation
    Inventors: Stilian Pandev, Min-Yeong Moon, Andrei V. Shchegrov, Jonathan Madsen, Dimitry Sanko, Liran Yerushalmi, Alexander Kuznetsov, Mahendra Dubey
  • Publication number: 20220412734
    Abstract: An overlay metrology system may receive overlay data for in-die overlay targets within various fields on a skew training sample from one or more overlay metrology tools, wherein the in-die overlay targets within the fields have a range programmed overlay offsets, wherein the fields are fabricated with a range of programmed skew offsets. The system may further generate asymmetric target signals for the in-die overlay targets using an asymmetric function providing a value of zero when physical overlay is zero and a sign indicative of a direction of physical overlay. The system may further generate corrected overlay offsets for the in-die overlay targets on the asymmetric target signals, generate self-calibrated overlay offsets for the in-die overlay targets based on the programmed overlay offsets and the corrected overlay offsets, generate a trained overlay recipe, and generate overlay measurements for in-die overlay targets on additional samples using the trained overlay recipe.
    Type: Application
    Filed: September 13, 2021
    Publication date: December 29, 2022
    Inventors: Stilian Pandev, Min-Yeong Moon, Andrei V. Shchegrov, Jonathan Madsen, Dimitry Sanko, Liran Yerushalmi, Alexander Kuznetsov, Mahendra Dubey
  • Publication number: 20220357673
    Abstract: A self-calibrating overlay metrology system may receive device overlay data from device targets on a sample, determine preliminary device overlay measurements for the device targets including device-scale features using an overlay recipe with the device overlay data as inputs, receive assist overlay data from sets of assist targets on the sample including device-scale features, where a particular set of assist targets includes one or more target pairs formed with two overlay targets having programmed overlay offsets of a selected value with opposite signs along a particular measurement direction.
    Type: Application
    Filed: September 28, 2021
    Publication date: November 10, 2022
    Inventors: Stilian Pandev, Min-Yeong Moon, Andrei V. Shchegrov, Jonathan Madsen, Dimitry Sanko, Liran Yerushalmi, Alexander Kuznetsov, Mahendra Dubey