Patents by Inventor Pradeep Subrahmanyan

Pradeep Subrahmanyan 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: 20230367941
    Abstract: A method may include generating a residual curvature map for a substrate, the residual curvature map being based upon a measurement of a surface of the substrate. The method may include generating a dose map based upon the residual curvature map, the dose map being for processing the substrate using a patterning energy source; and applying the dose map to process the substrate using the patterning energy source.
    Type: Application
    Filed: May 8, 2023
    Publication date: November 16, 2023
    Applicant: Applied Materials, Inc.
    Inventor: Pradeep Subrahmanyan
  • Publication number: 20230369014
    Abstract: A method may include generating a residual curvature map for a substrate, the residual curvature map being based upon a measurement of the substrate. The method may include generating a dose map based upon the residual curvature map, the dose map being for processing the substrate using a patterning energy source. The method may include applying the dose map to process the substrate using the patterning energy source, wherein the dose map is applied by performing a plurality of exposures of the substrate to the patterning energy source, at a plurality of different twist angles.
    Type: Application
    Filed: May 8, 2023
    Publication date: November 16, 2023
    Applicant: Applied Materials, Inc.
    Inventor: Pradeep Subrahmanyan
  • Publication number: 20220359208
    Abstract: Methods of forming a nanosheet field effect transistor (FET) device with reduced source/drain contact resistance are provided herein. In some embodiments, a method of forming an FET device includes: etching a nanosheet stack of the nanosheet FET device to form a plurality of first source/drain regions and a plurality of second source/drain regions, the nanosheet stack comprising alternating layers of nanosheet channel layers and sacrificial nanosheet layers; depositing a silicide layer in the plurality of first source/drain regions at ends of the nanosheet channel layers via a selective silicidation process to control a length of the nanosheet channel layers between the first source/drain regions; and performing a metal fill process to fill the plurality of first source/drain regions, wherein the metal fill extends from a lowermost nanosheet channel layer to above an uppermost nanosheet channel layer to facilitate the reduced source/drain contact resistance.
    Type: Application
    Filed: May 3, 2022
    Publication date: November 10, 2022
    Inventors: Sankuei LIN, Pradeep SUBRAHMANYAN
  • Publication number: 20220344171
    Abstract: Embodiments herein are directed to localized stress modulation by implanting a first side of a substrate to reduce in-plane distortion along a second side of the substrate. In some embodiments, a method may include providing a substrate, the substrate comprising a first main side opposite a second main side, wherein a plurality of features are disposed on the first main side, performing a metrology scan to the first main side to determine an amount of distortion to the substrate due to the formation of the plurality of features, and depositing a stress compensation film along the second main side of the substrate, wherein a stress and a thickness of the stress compensation film is determined based on the amount of distortion to the substrate. The method may further include directing ions to the stress compensation film in an ion implant procedure.
    Type: Application
    Filed: August 6, 2021
    Publication date: October 27, 2022
    Applicant: Applied Materials, Inc.
    Inventors: Sony Varghese, Pradeep Subrahmanyan, Dennis Rodier, Kyuha Shim
  • Patent number: 11092433
    Abstract: The methods and systems disclosed here detect edges of top-down images of respective cross-sections of an array of high-aspect-ratio (HAR) features. The respective cross sections are at various depths of a HAR feature along a longitudinal direction. The detected edges are re-sampled in a spatial domain at a target angular resolution. The re-sampled edges are represented as a corresponding set of harmonics in a frequency domain, each set of harmonics preserving characteristic information about a respective cross-section of the HAR feature at a certain depth. A plurality of cross-sections at the various depths of the HAR feature are reconstructed by analyzing the corresponding sets of harmonics in the frequency domain. A 3D profile of the HAR feature is generated by stitching the plurality of re-constructed cross-sections at the various depths of the HAR feature.
    Type: Grant
    Filed: May 12, 2020
    Date of Patent: August 17, 2021
    Assignee: Applied Materials, Inc.
    Inventor: Pradeep Subrahmanyan
  • Publication number: 20200271442
    Abstract: The methods and systems disclosed here detect edges of top-down images of respective cross-sections of an array of high-aspect-ratio (HAR) features. The respective cross sections are at various depths of a HAR feature along a longitudinal direction. The detected edges are re-sampled in a spatial domain at a target angular resolution. The re-sampled edges are represented as a corresponding set of harmonics in a frequency domain, each set of harmonics preserving characteristic information about a respective cross-section of the HAR feature at a certain depth. A plurality of cross-sections at the various depths of the HAR feature are reconstructed by analyzing the corresponding sets of harmonics in the frequency domain. A 3D profile of the HAR feature is generated by stitching the plurality of re-constructed cross-sections at the various depths of the HAR feature.
    Type: Application
    Filed: May 12, 2020
    Publication date: August 27, 2020
    Inventor: Pradeep Subrahmanyan
  • Publication number: 20200173772
    Abstract: The methods and systems disclosed here leverage currently available reliable top down imaging techniques used by SEMs and use computational methods to synthesize accurate 3D profiles of features of high aspect ratio structures in a device. Radial cross-sectional profiles obtained from different locations along the lateral direction at different heights/depths are stitched together to create one composite 3D profile of the HAR feature.
    Type: Application
    Filed: November 30, 2018
    Publication date: June 4, 2020
    Inventor: Pradeep Subrahmanyan
  • Patent number: 10670393
    Abstract: The methods and systems disclosed here leverage currently available reliable top down imaging techniques used by SEMs and use computational methods to synthesize accurate 3D profiles of features of high aspect ratio structures in a device. Radial cross-sectional profiles obtained from different locations along the lateral direction at different heights/depths are stitched together to create one composite 3D profile of the HAR feature.
    Type: Grant
    Filed: November 30, 2018
    Date of Patent: June 2, 2020
    Assignee: APPLIED MATERIALS, INC.
    Inventor: Pradeep Subrahmanyan
  • Patent number: 10409171
    Abstract: A process control system may include a controller configured to receive after-development inspection (ADI) data after a lithography step for the current layer from an ADI tool, receive after etch inspection (AEI) overlay data after an exposure step of the current layer from an AEI tool, train a non-zero offset predictor with ADI data and AEI overlay data to predict a non-zero offset from input ADI data, generate values of the control parameters of the lithography tool using ADI data and non-zero offsets generated by the non-zero offset predictor, and provide the values of the control parameters to the lithography tool for fabricating the current layer on the at least one production sample.
    Type: Grant
    Filed: January 10, 2018
    Date of Patent: September 10, 2019
    Assignee: KLA-Tencor Corporation
    Inventors: Michael E. Adel, Amnon Manassen, William Pierson, Ady Levy, Pradeep Subrahmanyan, Liran Yerushalmi, DongSub Choi, Hoyoung Heo, Dror Alumot, John Charles Robinson
  • Patent number: 10381256
    Abstract: An apparatus for fixing a wafer, including a chuck having a surface, a plurality of through bores in the chuck extending through the surface of the chuck, a fixed vacuum bellows, and a plurality of floating air bearings, wherein the fixed vacuum bellows and a respective floating air bearing of the plurality of floating air bearings are each individually arranged in separate through bores of the plurality of through bores and elevationally above the surface of the chuck.
    Type: Grant
    Filed: March 9, 2016
    Date of Patent: August 13, 2019
    Assignee: KLA-Tencor Corporation
    Inventors: Pradeep Subrahmanyan, Luping Huang, Chris Pohlhammer
  • Patent number: 10216096
    Abstract: A lithography system includes an illumination source and a set of projection optics. The illumination source directs a beam of illumination from an off-axis illumination pole to a pattern mask. The pattern mask includes a set of pattern elements to generate a set of diffracted beams including illumination from the illumination pole. At least two diffracted beams of the set of diffracted beams received by the set of projection optics are asymmetrically distributed in a pupil plane of the set of projection optics. The at least two diffracted beams of the set of diffracted beams are asymmetrically incident on the sample to form a set of fabricated elements corresponding to an image of the set of pattern elements. The set of fabricated elements on the sample includes one or more indicators of a location of the sample along an optical axis of the set of projection optics.
    Type: Grant
    Filed: June 6, 2016
    Date of Patent: February 26, 2019
    Assignee: KLA-Tencor Corporation
    Inventors: Myungjun Lee, Mark D. Smith, Sanjay Kapasi, Stilian Pandev, Dzmitry Sanko, Pradeep Subrahmanyan, Ady Levy
  • Patent number: 10209627
    Abstract: A lithography system includes an illumination source, projection optical elements, and a pattern mask. The illumination source includes one or more illumination poles. The pattern mask includes a set of focus-sensitive mask elements distributed with a pitch and, is configured to diffract illumination from the one or more illumination poles. The pitch may be selected such that two diffraction orders of illumination associated with each of the one or more illumination poles are asymmetrically distributed in a pupil plane of the projection optical elements. Further, the projection optical elements may expose a sample with an image of the set of focus-sensitive pattern mask elements based on the two diffraction orders of illumination associated with each of the one or more illumination poles such that one or more printing characteristics is indicative of a position of the sample within a focal volume of the projection optical elements.
    Type: Grant
    Filed: January 24, 2017
    Date of Patent: February 19, 2019
    Assignee: KLA-Tencor Corporation
    Inventors: Myungjun Lee, Stewart Robertson, Mark D. Smith, Pradeep Subrahmanyan
  • Publication number: 20180253017
    Abstract: A process control system may include a controller configured to receive after-development inspection (ADI) data after a lithography step for the current layer from an ADI tool, receive after etch inspection (AEI) overlay data after an exposure step of the current layer from an AEI tool, train a non-zero offset predictor with ADI data and AEI overlay data to predict a non-zero offset from input ADI data, generate values of the control parameters of the lithography tool using ADI data and non-zero offsets generated by the non-zero offset predictor, and provide the values of the control parameters to the lithography tool for fabricating the current layer on the at least one production sample.
    Type: Application
    Filed: January 10, 2018
    Publication date: September 6, 2018
    Inventors: Michael E. Adel, Amnon Manassen, William Pierson, Ady Levy, Pradeep Subrahmanyan, Liran Yerushalmi, DongSub Choi, Hoyoung Heo, Dror Alumot, John Charles Robinson
  • Publication number: 20180196358
    Abstract: A lithography system includes an illumination source, one or more projection optical elements, and a pattern mask. The illumination source includes one or more illumination poles. The pattern mask includes a set of focus-sensitive mask elements periodically distributed with a pitch, wherein the set of focus-sensitive mask elements is configured to diffract illumination from the one or more illumination poles. The pitch is selected such that two diffraction orders of illumination associated with each of the one or more illumination poles are asymmetrically distributed in a pupil plane of the one or more projection optical elements. Further, the one or more projection optical elements are configured to expose a sample with an image of the set of focus-sensitive pattern mask elements based on the two diffraction orders of illumination associated with each of the one or more illumination poles.
    Type: Application
    Filed: January 24, 2017
    Publication date: July 12, 2018
    Inventors: Myungjun Lee, Stewart Robertson, Mark D. Smith, Pradeep Subrahmanyan
  • Publication number: 20170045826
    Abstract: A lithography system includes an illumination source and a set of projection optics. The illumination source directs a beam of illumination from an off-axis illumination pole to a pattern mask. The pattern mask includes a set of pattern elements to generate a set of diffracted beams including illumination from the illumination pole. At least two diffracted beams of the set of diffracted beams received by the set of projection optics are asymmetrically distributed in a pupil plane of the set of projection optics. The at least two diffracted beams of the set of diffracted beams are asymmetrically incident on the sample to form a set of fabricated elements corresponding to an image of the set of pattern elements. The set of fabricated elements on the sample includes one or more indicators of a location of the sample along an optical axis of the set of projection optics.
    Type: Application
    Filed: June 6, 2016
    Publication date: February 16, 2017
    Inventors: Myungjun Lee, Mark D. Smith, Sanjay Kapasi, Stilian Pandev, Dimitry Sanko, Pradeep Subrahmanyan, Ady Levy
  • Publication number: 20160268156
    Abstract: An apparatus tor fixing a wafer, including a chuck having a surface, a plurality of through bores in the chuck extending through the surface of the chuck, a fixed vacuum bellows, and a plurality of floating air bearings, wherein the fixed vacuum bellows and a respective floating air bearing of the plurality of floating air bearings are each individually arranged in separate through bores of the plurality of through bores and elevationally above the surface of the chuck.
    Type: Application
    Filed: March 9, 2016
    Publication date: September 15, 2016
    Inventors: Pradeep Subrahmanyan, Luping HUANG, Chris POHLHAMMER
  • Publication number: 20150310160
    Abstract: A method and system for generating high density registration maps for masks is disclosed. A data preparation module generates a plurality of anchor points of the mask. Additionally, the data preparation module generates a plurality of sample points. Weights are generated as well in the data preparation module and the weights are used later on in the data fusion module. The positions of anchor points are measured with a registration tool in a mask coordinate system according to a generated recipe. The positions of sample points are determined with an inspection tool in a mask coordinate system according to a generated recipe. The measured positions of the anchor points and the measured positions of the sample points are passed to a data fusion module where a registration map is determined.
    Type: Application
    Filed: July 9, 2015
    Publication date: October 29, 2015
    Inventors: Frank LASKE, Mohammad M. DANESHPANAH, Pradeep SUBRAHMANYAN, Yalin XIONG
  • Patent number: 8779635
    Abstract: A reticle positioning apparatus for actinic EUV reticle inspection including a sealed inspection chamber containing a reticle stage for holding a reticle. The reticle stage has a magnetically suspended upper stage with a long travel in a “y” direction and a magnetically suspended lower stage with a long travel in an “x” direction; and a cable stage chamber isolated from the inspection chamber by a cable chamber wall. The cable stage chamber has a cable stage movable in the “y” direction; and a tube connected at one end to the reticle stage and to the cable stage at the other end. The tube passes from the cable stage through the inspection chamber through a seal in the chamber wall and opening into the cable entry chamber for entry of cables and hoses within the cable stage chamber, which cables and hoses pass through the tube to the reticle stage.
    Type: Grant
    Filed: April 9, 2013
    Date of Patent: July 15, 2014
    Assignee: KLA-Tencor Corporation
    Inventors: Pradeep Subrahmanyan, Mark Williams, Samir Nayfeh
  • Patent number: 8772731
    Abstract: A method for synchronizing sample stage motion with a time delay integration (TDI) charge-couple device (CCD) in a semiconductor inspection tool, including: measuring a lateral position of a stage holding a sample being inspected; measuring a vertical position of the stage; determining a corrected lateral position of an imaged pixel of the sample based on the measured lateral and vertical positions; and synchronizing charge transfer of the TDI CCD with the corrected lateral position of the imaged pixel.
    Type: Grant
    Filed: April 12, 2013
    Date of Patent: July 8, 2014
    Assignee: KLA-Tencor Corporation
    Inventors: Pradeep Subrahmanyan, Daniel Wack, Michael Wright, David Alles
  • Publication number: 20130270444
    Abstract: A method for synchronizing sample stage motion with a time delay integration (TDI) charge-couple device (CCD) in a semiconductor inspection tool, including: measuring a lateral position of a stage holding a sample being inspected; measuring a vertical position of the stage; determining a corrected lateral position of an imaged pixel of the sample based on the measured lateral and vertical positions; and synchronizing charge transfer of the TDI CCD with the corrected lateral position of the imaged pixel.
    Type: Application
    Filed: April 12, 2013
    Publication date: October 17, 2013
    Applicant: KLA-Tencor Corporation
    Inventors: Pradeep Subrahmanyan, Daniel Wack, Michael Wright, David Alles