Patents by Inventor Sidlgata V. Sreenivasan

Sidlgata V. Sreenivasan 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: 9972698
    Abstract: Methods for fabricating and replicating self-aligned multi-tier nanoscale structures for a variety of cross-sectional geometries. These methods can utilize a single lithography step whereby the need for alignment and overlay in the process is completely eliminated thereby enabling near-zero overlay error. Furthermore, techniques are developed to use these methods to fabricate self-aligned nanoscale multi-level/multi-height patterns with various shapes for master templates, replica templates and nanoimprint based pattern replication. Furthermore, the templates can be used to pattern multiple levels in a sacrificial polymer resist and achieve pattern transfer of the levels into a variety of substrates to form completed large area nanoelectronic and nanophotonic devices using only one patterning step.
    Type: Grant
    Filed: February 26, 2018
    Date of Patent: May 15, 2018
    Assignee: Board of Regents, The University of Texas System
    Inventors: Sidlgata V. Sreenivasan, Praveen Joseph, Ovadia Abed, Michelle Grigas, Akhila Mallavarapu, Paras Ajay
  • Patent number: 9972699
    Abstract: Methods for fabricating and replicating self-aligned multi-tier nanoscale structures for a variety of cross-sectional geometries. These methods can utilize a single lithography step whereby the need for alignment and overlay in the process is completely eliminated thereby enabling near-zero overlay error. Furthermore, techniques are developed to use these methods to fabricate self-aligned nanoscale multi-level/multi-height patterns with various shapes for master templates, replica templates and nanoimprint based pattern replication. Furthermore, the templates can be used to pattern multiple levels in a sacrificial polymer resist and achieve pattern transfer of the levels into a variety of substrates to form completed large area nanoelectronic and nanophotonic devices using only one patterning step.
    Type: Grant
    Filed: February 26, 2018
    Date of Patent: May 15, 2018
    Assignee: Board of Regents, The University of Texas System
    Inventors: Sidlgata V. Sreenivasan, Praveen Joseph, Ovadia Abed, Michelle Grigas, Akhila Mallavarapu, Paras Ajay
  • Patent number: 9941389
    Abstract: Methods for fabricating and replicating self-aligned multi-tier nanoscale structures for a variety of cross-sectional geometries. These methods can utilize a single lithography step whereby the need for alignment and overlay in the process is completely eliminated thereby enabling near-zero overlay error. Furthermore, techniques are developed to use these methods to fabricate self-aligned nanoscale multi-level/multi-height patterns with various shapes for master templates, replica templates and nanoimprint based pattern replication. Furthermore, the templates can be used to pattern multiple levels in a sacrificial polymer resist and achieve pattern transfer of the levels into a variety of substrates to form completed large area nanoelectronic and nanophotonic devices using only one patterning step.
    Type: Grant
    Filed: April 19, 2016
    Date of Patent: April 10, 2018
    Assignee: Board of Regents, The University of Texas System
    Inventors: Sidlgata V. Sreenivasan, Praveen Joseph, Ovadia Abed, Michelle Grigas, Akhila Mallavarapu, Paras Ajay
  • Publication number: 20170333940
    Abstract: A method and alignment system for minimizing errors in the deposition of films of tailored thickness. A first position on a stage is identified for optimal placement of a downward looking microscope (DLM) and an upward looking microscope (ULM) when alignment marks on the DLM and ULM are aligned, where the DLM is attached to a bridge and the ULM is attached to the stage. A second position on the stage is identified when the ULM on the stage is aligned with the alignment marks on a metrology tool. A surface of a chucked substrate affixed to the stage is then measured. A map between a substrate coordinate system and a metrology coordinate system may then be obtained using the measured surface of the chucked substrate with the first and second positions.
    Type: Application
    Filed: May 19, 2017
    Publication date: November 23, 2017
    Inventors: Sidlgata V. Sreenivasan, Shrawan Singhal
  • Patent number: 9778562
    Abstract: An imprint lithography template or imprinting stack includes a porous material defining a multiplicity of pores with an average pore size of at least about 0.4 nm. A porosity of the porous material is at least about 10%. The porous template, the porous imprinting stack, or both may be used in an imprint lithography process to facilitate diffusion of gas trapped between the template and the imprinting stack into the template, the imprinting stack or both, such that polymerizable material between the imprinting stack and the template rapidly forms a substantially continuous layer between the imprinting stack and the template.
    Type: Grant
    Filed: November 21, 2008
    Date of Patent: October 3, 2017
    Assignee: Canon Nanotechnologies, Inc.
    Inventors: Frank Y. Xu, Weijun Liu, Edward Brian Fletcher, Sidlgata V. Sreenivasan, Byung Jin Choi, Niyaz Khusnatdinov, Anshuman Cherala, Kosta S. Selinidis
  • Patent number: 9718096
    Abstract: An inkjet-based process for programmable deposition of thin films of a user-defined profile. Drops of a pre-cursor liquid organic material are dispensed at various locations on a substrate by a multi-jet. A superstrate is held in a roll-to-roll configuration such that a first contact of the drops is made by a front side of the superstrate thereby initiating a liquid front that spreads outward merging with the drops to form a contiguous film captured between the substrate and the superstrate. A non-equilibrium transient state of the superstrate, the contiguous film and the substrate then occurs after a duration of time. The contiguous film is then cured to crosslink it into a polymer. The superstrate is then separated from the polymer thereby leaving a polymer film on the substrate. In such a manner, non-uniform films can be formed without significant material wastage in an inexpensive manner.
    Type: Grant
    Filed: July 12, 2016
    Date of Patent: August 1, 2017
    Assignee: Board of Regents, The University of Texas System
    Inventors: Sidlgata V. Sreenivasan, Shrawan Singhal, Ovadia Abed, Lawrence Dunn
  • Publication number: 20170131640
    Abstract: Techniques for delivering sub-5 nm overlay control over multiple fields. One such technique reduces overlay from the wafer side using wafer-thermal actuators. In another technique, the topology of the template is optimized so that the inter-field mechanical coupling between fields in the multi-field template is reduced thereby allowing overlay to be simultaneously reduced in multiple fields in the template. A further technique combines the wafer-thermal and template actuation techniques to achieve significantly improved single and multi-field overlay performance.
    Type: Application
    Filed: November 4, 2016
    Publication date: May 11, 2017
    Inventors: Sidlgata V. Sreenivasan, Paras Ajay, Anshuman Cherala
  • Publication number: 20170106399
    Abstract: A method for depositing thin films using a nominally curved substrate. Drops of a pre-cursor liquid organic material are dispensed at a plurality of locations on a nominally curved substrate by one or more inkjets. A superstrate is brought down on the dispensed drops to close the gap between the superstrate and the substrate thereby allowing the drops to form a contiguous film captured between the substrate and the superstrate. A non-equilibrium transient state of the superstrate, the contiguous film and the substrate is enabled to occur after a duration of time. The contiguous film is then cured to solidify it into a solid. The solid is separated from the superstrate thereby leaving a polymer film on the substrate. In this manner, such a technique for film deposition has the film thickness range, resolution and variation required to be applicable for a broad spectrum of applications.
    Type: Application
    Filed: October 14, 2016
    Publication date: April 20, 2017
    Inventors: Sidlgata V. Sreenivasan, Shrawan Singhal
  • Patent number: 9616614
    Abstract: Methods and systems are provided for patterning polymerizable material dispensed on flexible substrates or flat substrates using imprint lithography techniques. Template replication methods and systems are also presented where patterns from a master are transferred to flexible substrates to form flexible film templates. Such flexible film templates are then used to pattern large area flat substrates. Contact between the imprint template and substrate can be initiated and propagated by relative translation between the template and the substrate.
    Type: Grant
    Filed: February 21, 2013
    Date of Patent: April 11, 2017
    Assignees: Canon Nanotechnologies, Inc., Molecular Imprints, Inc.
    Inventors: Byung-Jin Choi, Se Hyun Ahn, Mahadevan GanapathiSubramanian, Michael N. Miller, Sidlgata V. Sreenivasan
  • Publication number: 20160318066
    Abstract: An inkjet-based process for programmable deposition of thin films of a user-defined profile. Drops of a pre-cursor liquid organic material are dispensed at various locations on a substrate by a multi-jet. A superstrate is held in a roll-to-roll configuration such that a first contact of the drops is made by a front side of the superstrate thereby initiating a liquid front that spreads outward merging with the drops to form a contiguous film captured between the substrate and the superstrate. A non-equilibrium transient state of the superstrate, the contiguous film and the substrate then occurs after a duration of time. The contiguous film is then cured to crosslink it into a polymer. The superstrate is then separated from the polymer thereby leaving a polymer film on the substrate. In such a manner, non-uniform films can be formed without significant material wastage in an inexpensive manner.
    Type: Application
    Filed: July 12, 2016
    Publication date: November 3, 2016
    Inventors: Sidlgata V. Sreenivasan, Shrawan Singhal, Ovadia Abed, Lawrence Dunn
  • Publication number: 20160307790
    Abstract: A pin mechanism and a method for reducing backside particle induced out-of-plane distortions in semiconductor wafers involving such pin mechanisms. Geometric parameters of the pin are optimized so as to maximize the height of a particle trapped between a backside of the wafer and one of the contact lands without exceeding a selected maximum out-of-plane distortion. These geometric parameters are optimized in various designs of the pin mechanism, such as a pin mechanism that includes secondary leaf-type flexures attached to the contact lands and a single stem attached to a base portion of a cross-member of the pin. An alternative pin mechanism includes notch-type flexures, as opposed to secondary leaf-type flexures, connected to the cross-member of the pin. Furthermore, a plurality of stems are attached to the base portion of the cross-member of the pin. Alternatively, such a pin mechanism may utilize a different number of stems (e.g., one stem).
    Type: Application
    Filed: April 20, 2016
    Publication date: October 20, 2016
    Inventors: Sidlgata V. Sreenivasan, Andrew Westfahl, Paras Ajay
  • Publication number: 20160308020
    Abstract: Methods for fabricating and replicating self-aligned multi-tier nanoscale structures for a variety of cross-sectional geometries. These methods can utilize a single lithography step whereby the need for alignment and overlay in the process is completely eliminated thereby enabling near-zero overlay error. Furthermore, techniques are developed to use these methods to fabricate self-aligned nanoscale multi-level/multi-height patterns with various shapes for master templates, replica templates and nanoimprint based pattern replication. Furthermore, the templates can be used to pattern multiple levels in a sacrificial polymer resist and achieve pattern transfer of the levels into a variety of substrates to form completed large area nanoelectronic and nanophotonic devices using only one patterning step.
    Type: Application
    Filed: April 19, 2016
    Publication date: October 20, 2016
    Inventors: Sidlgata V. Sreenivasan, Praveen Joseph, Ovadia Abed, Michelle Grigas, Akhila Mallavarapu, Paras Ajay
  • Patent number: 9415418
    Abstract: An inkjet-based process for programmable deposition of thin films of a user-defined profile. Drops of a pre-cursor liquid organic material are dispensed at various locations on a substrate by a multi-jet. A superstrate that has been bowed due to a backside pressure is brought down such that a first contact of the drops is made by a front side of the superstrate thereby initiating a liquid front that spreads outward merging with the drops to form a contiguous film captured between the substrate and the superstrate. A non-equilibrium transient state of the superstrate, the contiguous film and the substrate then occurs after a duration of time. The contiguous film is then cured to crosslink it into a polymer. The superstrate is then separated from the polymer thereby leaving a polymer film on the substrate. In such a manner, non-uniform films can be formed without significant material wastage in an inexpensive manner.
    Type: Grant
    Filed: August 18, 2014
    Date of Patent: August 16, 2016
    Assignee: Board of Regents, The University of Texas System
    Inventors: Sidlgata V. Sreenivasan, Shrawan Singhal
  • Publication number: 20160118249
    Abstract: A method for template fabrication of ultra-precise nanoscale shapes. Structures with a smooth shape (e.g., circular cross-section pillars) are formed on a substrate using electron beam lithography. The structures are subject to an atomic layer deposition of a dielectric interleaved with a deposition of a conductive film leading to nanoscale sharp shapes with features that exceed electron beam resolution capability of sub-10 nm resolution. A resist imprint of the nanoscale sharp shapes is performed using J-FIL. The nanoscale sharp shapes are etched into underlying functional films on the substrate forming a nansohaped template with nanoscale sharp shapes that include sharp corners and/or ultra-small gaps. In this manner, sharp shapes can be retained at the nanoscale level. Furthermore, in this manner, imprint based shape control for novel shapes beyond elementary nanoscale structures, such as dots and lines, can occur at the nanoscale level.
    Type: Application
    Filed: October 23, 2015
    Publication date: April 28, 2016
    Inventors: Sidlgata V. Sreenivasan, Anshuman Cherala, Meghali Chopra, Roger Bonnecaze, Ovadia Abed, Bailey Yin, Akhila Mallavarapu, Shrawan Singhal, Brian Gawlik
  • Patent number: 9223202
    Abstract: Disclosed herein is an automatic fluid dispensing method and system for dispensing fluid on the surface of a plate-like material, or substrate, including a semiconductor wafer for imprint lithography processes. The dispensing method uses fluid dispenser and a substrate stage that may generate relative lateral motions between a fluid dispenser tip a substrate. Also described herein are methods and devices for creating a planar surface on a substrate using a substantially unpatterned planar template.
    Type: Grant
    Filed: July 9, 2007
    Date of Patent: December 29, 2015
    Assignee: Board of Regents, The University of Texas System
    Inventors: Byung-Jin Choi, Sidlgata V. Sreenivasan, Carlton Grant Willson, Mattherw E. Colburn, Todd C. Bailey, John G. Ekerdt
  • Patent number: 9196765
    Abstract: Systems and methods for fabrication of nanostructured solar cells having arrays of nanostructures are described, including nanostructured solar cells having a repeating pattern of pyramid nanostructures, providing for low cost thin-film solar cells with improved PCE.
    Type: Grant
    Filed: May 19, 2015
    Date of Patent: November 24, 2015
    Assignee: MOLECULAR IMPRINTS, INC.; BOARD OF REGENTS, THE UNIVERSITY OF TEXAS SYSTEM
    Inventors: Shuqiang Yang, Michael N. Miller, Mohamed M. Hilali, Fen Wan, Gerard M. Schmid, Liang Wang, Sidlgata V. Sreenivasan, Frank Y. Xu
  • Publication number: 20150255640
    Abstract: Systems and methods for fabrication of nanostructured solar cells having arrays of nanostructures are described, including nanostructured solar cells having a repeating pattern of pyramid nanostructures, providing for low cost thin-film solar cells with improved PCE.
    Type: Application
    Filed: May 19, 2015
    Publication date: September 10, 2015
    Inventors: Shuqiang Yang, Michael N. Miller, Mohamed M. Hilali, Fen Wan, Gerard M. Schmid, Liang Wang, Sidlgata V. Sreenivasan, Frank Y. Xu
  • Publication number: 20150183151
    Abstract: Systems and methods for partial field imprinting are provided such that imprint templates are asymmetrically modulated to allow initial contact with a partial field on a substrate at a location spaced apart from the template center.
    Type: Application
    Filed: December 31, 2014
    Publication date: July 2, 2015
    Inventors: Mahadevan Ganapathisubramanian, Matthew M. Kincaid, Byung-Jin Choi, Sidlgata V. Sreenivasan
  • Patent number: 9070803
    Abstract: Systems and methods for fabrication of nanostructured solar cells having arrays of nanostructures are described, including nanostructured solar cells having a repeating pattern of pyramid nanostructures, providing for low cost thin-film solar cells with improved PCE.
    Type: Grant
    Filed: May 11, 2011
    Date of Patent: June 30, 2015
    Assignee: Molecular Imprints, Inc.
    Inventors: Shuqiang Yang, Michael N. Miller, Mohamed M. Hilali, Fen Wan, Gerard M. Schmid, Liang Wang, Sidlgata V. Sreenivasan, Frank Y. Xu
  • Publication number: 20150165671
    Abstract: Control of lateral strain and lateral strain ratio (dt/db) between template and substrate through the selection of template and/or substrate thicknesses (Tt and/or Tb), control of template and/or substrate back pressure (Pt and/or Pb), and/or selection of material stiffness are described.
    Type: Application
    Filed: February 26, 2015
    Publication date: June 18, 2015
    Inventors: Se-Hyuk Im, Mahadevan Ganapathisubramanian, Edward Brian Fletcher, Niyaz Khusnatdinov, Gerard M. Schmid, Mario Johannes Meissl, Anshuman Cherala, Frank Y. Xu, Byung-Jin Choi, Sidlgata V. Sreenivasan