Patents by Inventor Sateesh KOKA

Sateesh KOKA 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: 20160141294
    Abstract: A contact via structure can include a ruthenium portion formed by selective deposition of ruthenium on a semiconductor surface at the bottom of a contact trench. The ruthenium-containing portion can reduce contact resistance at the interface with an underlying doped semiconductor region. At least one conductive material portion can be formed in the remaining volume of the contact trench to form a contact via structure. Alternatively or additionally, a contact via structure can include a tensile stress-generating portion and a conductive material portion. In case the contact via structure is formed through an alternating stack of insulating layers and electrically conductive layers that include a compressive stress-generating material, the tensile stress-generating portion can at least partially cancel the compressive stress generated by the electrically conductive layers. The conductive material portion of the contact via structure can include a metallic material or a doped semiconductor material.
    Type: Application
    Filed: October 29, 2015
    Publication date: May 19, 2016
    Inventors: Somesh Peri, Sateesh Koka, Raghuveer S. Makala, Rahul Sharangpani, Matthias Baenninger, Jayavel Pachamuthu, Johann Alsmeier
  • Publication number: 20160118397
    Abstract: Methods of making monolithic three-dimensional memory devices include performing a first etch to form a memory opening and a second etch using a different etching process to remove a damaged portion of the semiconductor substrate from the bottom of the memory opening. A single crystal semiconductor material is formed over the substrate in the memory opening using an epitaxial growth process. Additional embodiments include improving the quality of the interface between the semiconductor channel material and the underlying semiconductor layers in the memory opening which may be damaged by the bottom opening etch, including forming single crystal semiconductor channel material by epitaxial growth from the bottom surface of the memory opening and/or oxidizing surfaces exposed to the bottom opening etch and removing the oxidized surfaces prior to forming the channel material. Monolithic three-dimensional memory devices formed by the embodiment methods are also disclosed.
    Type: Application
    Filed: October 24, 2014
    Publication date: April 28, 2016
    Inventors: Sateesh KOKA, Raghuveer S. MAKALA, Yanli ZHANG, Senaka KANAKAMEDALA, Rahul SHARANGPANI, Yao-Sheng LEE, George MATAMIS
  • Patent number: 9305849
    Abstract: A monolithic three dimensional NAND string includes a semiconductor channel, an end part of the semiconductor channel extending substantially perpendicular to a major surface of a substrate, a plurality of control gate electrodes extending substantially parallel to the major surface of the substrate, a charge storage material layer located between the plurality of control gate electrodes and the semiconductor channel, a tunnel dielectric located between the charge storage material layer and the semiconductor channel, and a blocking dielectric containing a plurality of clam-shaped portions each having two horizontal portions connected by a vertical portion. Each of the plurality of control gate electrodes are located at least partially in an opening in the clam-shaped blocking dielectric, and a plurality of discrete cover oxide segments embedded in part of a thickness of the charge storage material layer and located between the blocking dielectric and the charge storage material layer.
    Type: Grant
    Filed: November 12, 2014
    Date of Patent: April 5, 2016
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Masanori Tsutsumi, Shigehiro Fujino, Sateesh Koka, Senaka Kanakamedala, Yanli Zhang, Raghuveer S. Makala, Rahul Sharangpani, George Matamis, Wei Zhao
  • Patent number: 9236396
    Abstract: A monolithic three dimensional NAND string includes a semiconductor channel, at least one end part of the semiconductor channel extending substantially perpendicular to a major surface of a substrate and a plurality of control gate electrodes extending substantially parallel to the major surface of the substrate. The NAND string also includes a memory film located between the semiconductor channel and the plurality of control gate electrodes and a blocking dielectric containing a plurality of clam-shaped portions each having two horizontal portions connected by a vertical portion. The NAND string also includes a plurality of discrete cover silicon oxide segments located between the memory film and each respective clam-shaped portion of the blocking dielectric containing a respective control gate electrode. Each of the plurality of cover silicon oxide segments has curved upper and lower sides and substantially straight vertical sidewalls.
    Type: Grant
    Filed: November 12, 2014
    Date of Patent: January 12, 2016
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Sateesh Koka, Senaka Kanakamedala, Yanli Zhang, Raghuveer S. Makala, Rahul Sharangpani, George Matamis, Wei Zhao
  • Publication number: 20150294978
    Abstract: A method of making a vertical NAND device includes forming a lower portion of a memory stack over a substrate, forming a lower portion of memory openings in the lower portion of the memory stack, and forming a sacrificial material portion including an encapsulated cavity. The method also includes forming an upper portion of the memory stack over the lower portion of the memory stack and over the sacrificial material, forming an upper portion of the memory openings in the upper portion of the memory stack to expose the sacrificial material in the lower portion of the memory openings, removing the sacrificial material portion to connect the lower portion of the memory openings with a respective upper portion of the memory openings to form continuous memory openings, and forming a semiconductor channel in each continuous memory opening.
    Type: Application
    Filed: June 24, 2015
    Publication date: October 15, 2015
    Inventors: Zhenyu LU, Sateesh KOKA, James KAI, Raghuveer S. MAKALA, Yao-Sheng LEE, Jayavel PACHAMUTHU, Johann ALSMEIER, Henry CHIEN
  • Publication number: 20150279851
    Abstract: 3D NAND memory structures and related method are provided. In some embodiments such structures can include a control gate material and a floating gate material disposed between a first insulating layer and a second insulating layer, an interpoly dielectric (IPD) layer disposed between the floating gate material and control gate material such that the IPD layer electrically isolates the control gate material from the floating gate material, and a tunnel dielectric material deposited on the floating gate material opposite the control gate material.
    Type: Application
    Filed: March 27, 2014
    Publication date: October 1, 2015
    Inventors: Darwin Fan, Sateesh Koka, Gordon Haller, John Hopkins, Shyam Surthi, Anish Khandekar
  • Publication number: 20150179662
    Abstract: A memory film and a semiconductor channel can be formed within each memory opening that extends through a stack including an alternating plurality of insulator layers and sacrificial material layers. After formation of backside recesses through removal of the sacrificial material layers selective to the insulator layers, a metallic barrier material portion can be formed in each backside recess. A cobalt portion can be formed in each backside recess. Each backside recess can be filled with a cobalt portion alone, or can be filled with a combination of a cobalt portion and a metallic material portion including a material other than cobalt.
    Type: Application
    Filed: February 4, 2015
    Publication date: June 25, 2015
    Inventors: Raghuveer S. MAKALA, Rahul SHARANGPANI, Sateesh KOKA, Genta MIZUNO, Naoki TAKEGUCHI, Senaka Krishna KANAKAMEDALA, George MATAMIS, Yao-Sheng LEE, Johann ALSMEIER