Patents by Inventor Tanmay Kumar

Tanmay Kumar 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: 20180197988
    Abstract: A matrix rail structure is formed over a substrate. The matrix rail structure includes a pair of lengthwise sidewalls that extend along a first horizontal direction and comprises, or is at least partially subsequently replaced with, a set of at least one gate electrode rail extending along the first horizontal direction and straight-sidewalled gate dielectrics. A pair of vertical semiconductor channel strips and a pair of laterally-undulating gate dielectrics can be formed on sidewalls of the matrix rail structure for each vertical field effect transistor. At least one laterally-undulating gate electrode extending along the first horizontal direction is formed on the laterally-undulating gate dielectrics. Bottom active regions and top active regions are formed at end portions of the vertical semiconductor channel strips. The vertical field effect transistors can be formed as a two-dimensional array, and may be employed as access transistors for a three-dimensional memory device.
    Type: Application
    Filed: January 6, 2017
    Publication date: July 12, 2018
    Inventors: Perumal RATNAM, Christopher PETTI, Juan SAENZ, Guangle ZHOU, Abhijit BANDYOPADHYAY, Tanmay KUMAR
  • Publication number: 20180166559
    Abstract: A method is provided that includes forming a word line above a substrate, the word line disposed in a first direction, the word line including a first portion including a first conductive material and a second portion including a second conductive material, forming a bit line above the substrate, the bit line disposed in a second direction perpendicular to the first direction, forming a nonvolatile memory material between the word line and the bit line, the nonvolatile memory material including a semiconductor material layer and a conductive oxide material layer, the semiconductor material layer disposed adjacent the second portion of the word line, and forming a memory cell including the nonvolatile memory material at an intersection of the local bit line and the word line.
    Type: Application
    Filed: December 13, 2016
    Publication date: June 14, 2018
    Applicant: SANDISK TECHNOLOGIES LLC
    Inventors: Guangle Zhou, Chuanbin Pan, Juan Saenz, Tanmay Kumar
  • Publication number: 20180159033
    Abstract: Systems and methods for providing a Barrier Modulated Cell (BMC) structure that may comprise a reversible resistance-switching memory element within a memory array are described. The BMC structure may include a barrier layer comprising a layer of amorphous germanium or amorphous silicon germanium paired with a conductive metal oxide, such as titanium dioxide (TiO2), strontium titanate (SrTiO3), or a binary metal oxide. The BMC structure may include a conductive metal oxide in series with an amorphous layer of a low bandgap material. The low bandgap material may comprise a semiconductor material with a bandgap energy (Eg) less than 1.0 eV. The improved BMC structure may be used for providing multi-level memory elements within a three dimensional memory array.
    Type: Application
    Filed: February 6, 2018
    Publication date: June 7, 2018
    Applicant: SANDISK TECHNOLOGIES LLC
    Inventors: Ming-Che Wu, Tanmay Kumar
  • Patent number: 9953697
    Abstract: A volatile resistive memory device includes a resistive memory element including a barrier material portion and a charge-modulated resistive memory material portion. The barrier material portion includes a material selected from germanium and a silicon-germanium alloy, and the charge-modulated resistive memory material portion includes a non-filamentary, electrically conductive metal oxide. The resistive memory device may be a volatile eDRAM device. In operation, reading a resistance state of the resistive memory element does not disturb the resistance state of the charge-modulated resistive memory material portion.
    Type: Grant
    Filed: August 30, 2016
    Date of Patent: April 24, 2018
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Tanmay Kumar, Alper Ilkbahar
  • Patent number: 9923140
    Abstract: Systems and methods for providing a Barrier Modulated Cell (BMC) structure that may comprise a reversible resistance-switching memory element within a memory array are described. The BMC structure may include a barrier layer comprising a layer of amorphous germanium or amorphous silicon germanium paired with a conductive metal oxide, such as titanium dioxide (TiO2), strontium titanate (SrTiO3), or a binary metal oxide. The BMC structure may include a conductive metal oxide in series with an amorphous layer of a low bandgap material. The low bandgap material may comprise a semiconductor material with a bandgap energy (Eg) less than 1.0 eV. The improved BMC structure may be used for providing multi-level memory elements within a three dimensional memory array.
    Type: Grant
    Filed: September 20, 2016
    Date of Patent: March 20, 2018
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Ming-Che Wu, Tanmay Kumar
  • Patent number: 9805794
    Abstract: Two-terminal memory can be set to a first state (e.g., conductive state) in response to a program pulse, or set a second state (e.g., resistive state) in response to an erase pulse. These pulses generally provide a voltage difference between the two terminals of the memory cell. Certain electrical characteristics associated with the pulses can be manipulated in order to enhance the efficacy of the pulse. For example, the pulse can be enhanced or improved to reduce power-consumption associated with the pulse, reduce a number of pulses used to successfully set the state of the memory cell, reduce wear or damage to the memory cell, or to improve Ion or Ioff distribution associated with changing the state of the memory cell.
    Type: Grant
    Filed: May 19, 2015
    Date of Patent: October 31, 2017
    Assignee: CROSSBAR, INC.
    Inventors: Zhi Li, Tanmay Kumar, Sung Hyun Jo
  • Patent number: 9806256
    Abstract: A resistive memory device includes a first electrode, a sidewall spacer electrode located on a sidewall of a dielectric material contacting the first electrode, a resistive memory cell containing a resistive memory material and contacting the sidewall spacer electrode, and a second electrode containing the resistive memory cell.
    Type: Grant
    Filed: October 21, 2016
    Date of Patent: October 31, 2017
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Ming-Che Wu, Chuanbin Pan, Guangle Zhou, Tanmay Kumar
  • Publication number: 20170309819
    Abstract: Systems and methods for providing a Barrier Modulated Cell (BMC) structure that may comprise a reversible resistance-switching memory element within a memory array are described. The BMC structure may include a barrier layer comprising a layer of amorphous germanium or amorphous silicon germanium paired with a conductive metal oxide, such as titanium dioxide (TiO2), strontium titanate (SrTiO3), or a binary metal oxide. The BMC structure may include a conductive metal oxide in series with an amorphous layer of a low bandgap material. The low bandgap material may comprise a semiconductor material with a bandgap energy (Eg) less than 1.0 eV. The improved BMC structure may be used for providing multi-level memory elements within a three dimensional memory array.
    Type: Application
    Filed: September 20, 2016
    Publication date: October 26, 2017
    Applicant: SANDISK TECHNOLOGIES LLC
    Inventors: Ming-Che Wu, Tanmay Kumar
  • Publication number: 20170309324
    Abstract: A volatile resistive memory device includes a resistive memory element including a barrier material portion and a charge-modulated resistive memory material portion. The barrier material portion includes a material selected from germanium and a silicon-germanium alloy, and the charge-modulated resistive memory material portion includes a non-filamentary, electrically conductive metal oxide. The resistive memory device may be a volatile eDRAM device. In operation, reading a resistance state of the resistive memory element does not disturb the resistance state of the charge-modulated resistive memory material portion.
    Type: Application
    Filed: August 30, 2016
    Publication date: October 26, 2017
    Inventors: Tanmay KUMAR, Alper ILKBAHAR
  • Patent number: 9793474
    Abstract: A method of forming a non-volatile memory device. The method includes providing a substrate having a surface region and forming a first dielectric material overlying the surface region of the substrate. A first electrode structure is formed overlying the first dielectric material and a p+ polycrystalline silicon germanium material is formed overlying the first electrode structure. A p+ polycrystalline silicon material is formed overlying the first electrode structure using the polycrystalline silicon germanium material as a seed layer at a deposition temperature ranging from about 430 Degree Celsius to about 475 Degree Celsius without further anneal. The method forms a resistive switching material overlying the polycrystalline silicon material, and a second electrode structure including an active metal material overlying the resistive switching material.
    Type: Grant
    Filed: February 24, 2014
    Date of Patent: October 17, 2017
    Assignee: CROSSBAR, INC.
    Inventors: Xin Sun, Sung Hyun Jo, Tanmay Kumar
  • Patent number: 9768180
    Abstract: A method is provided that includes forming a dielectric material above a substrate, forming a hole in the dielectric material, the hole disposed in a first direction, forming a word line layer above the substrate via the hole, the word line layer disposed in a second direction perpendicular to the first direction, the word line layer including a first conductive material having a first work function, forming a nonvolatile memory material on a sidewall of the hole, the nonvolatile memory material including a semiconductor material layer and a conductive oxide material layer, forming a local bit line in the hole, the local bit line including a second conductive material having a second work function, wherein the first work function is greater than the second work function, and forming a memory cell comprising the nonvolatile memory material at an intersection of the local bit line and the word line layer.
    Type: Grant
    Filed: October 29, 2016
    Date of Patent: September 19, 2017
    Assignee: SanDisk Technologies LLC
    Inventors: Guangle Zhou, Yubao Li, Yangyin Chen, Tanmay Kumar
  • Patent number: 9735358
    Abstract: A method for forming a non-volatile memory device includes disposing a junction layer comprising a doped silicon-bearing material in electrical contact with a first conductive material, forming a switching layer comprising an undoped amorphous silicon-bearing material upon at least a portion of the junction layer, disposing a layer comprising a non-noble metal material upon at least a portion of the switching layer, disposing an active metal layer comprising a noble metal material upon at least a portion of the layer, and forming a second conductive material in electrical contact with the active metal layer.
    Type: Grant
    Filed: April 20, 2016
    Date of Patent: August 15, 2017
    Assignee: CROSSBAR, INC.
    Inventors: Sung Hyun Jo, Kuk-Hwan Kim, Tanmay Kumar
  • Patent number: 9729155
    Abstract: A method for an FPGA includes coupling a first electrode of a first resistive element to a first input voltage, coupling a second electrode of a second resistive element to a second input voltage, applying a first programming voltage to a shared node of a second electrode of the first resistive element, a first electrode of the second resistive element, and to a gate of a transistor element, and changing a resistance state of the first resistive element to a low resistance state while maintaining a resistance state of the second resistive element, when a voltage difference between the first programming voltage at the second terminal and the first input voltage at the first terminal exceeds a programming voltage associated with the first resistive element.
    Type: Grant
    Filed: July 18, 2014
    Date of Patent: August 8, 2017
    Assignee: CROSSBAR, INC.
    Inventors: Hagop Nazarian, Sang Thanh Nguyen, Tanmay Kumar
  • Patent number: 9673255
    Abstract: A method for forming a resistive memory device includes providing a substrate comprising a first metal material, forming a conductive silicon-bearing layer on top of the first metal material, wherein the conductive silicon-bearing layer comprises an upper region and a lower region, and wherein the lower region is adjacent to the first metal material, forming an amorphous layer from the upper region of the conductive silicon-bearing layer, and disposing an active metal material above the amorphous layer.
    Type: Grant
    Filed: January 14, 2015
    Date of Patent: June 6, 2017
    Assignee: CROSSBAR, INC.
    Inventors: Sung Hyun Jo, Kuk-Hwan Kim, Tanmay Kumar
  • Patent number: 9613694
    Abstract: Two-terminal memory can be set to a first state (e.g., conductive state) in response to a program pulse, or set a second state (e.g., resistive state) in response to an erase pulse. These pulses generally produce a voltage difference between the two terminals of the memory cell. Certain electrical characteristics associated with the pulses can be manipulated in order to enhance the efficacy of the pulse. For example, the pulse can be enhanced or improved to reduce power-consumption associated with the pulse, reduce a number of pulses used to successfully set the state of the memory cell, or to improve Ion distribution associated with active metal particles included in the memory cell.
    Type: Grant
    Filed: August 10, 2015
    Date of Patent: April 4, 2017
    Assignee: CROSSBAR, INC.
    Inventors: Zhi Li, Tanmay Kumar, Sung Hyun Jo
  • Publication number: 20160351625
    Abstract: A recessed high voltage metal oxide semiconductor (MOS) transistor is provided for use in a two-terminal memory cell. The two-terminal memory cell can include a resistive switching device connected to the recessed MOS transistor. The recessed MOS transistor provides for an increased channel length relative to the transistor size in comparison to a traditional MOS transistor. This allows for a decreased memory cell size while maintaining comparable electrical parameters (threshold voltage, channel length, and leakage) than would otherwise be possible. The recessed MOS transistor can be made as either a NMOS or PMOS device using n-type or p-type materials respectively, where the channel, or inversion layer, is formed by electrons (NMOS) or holes (PMOS) between the source and drain in the transistor.
    Type: Application
    Filed: May 29, 2015
    Publication date: December 1, 2016
    Inventors: Harry Yue Gee, Tanmay Kumar, Natividad Vasquez, JR., Steven Patrick Maxwell, Sundar Narayanan
  • Patent number: 9502102
    Abstract: Providing for a memory cell capable of forming a one time programmable, multi-level cell two-terminal memory cell or a rewritable, two terminal memory cell is described herein. In some embodiments, one time programmable, multi-level cell two-terminal memory cell can exhibit diode-like characteristics. In other embodiments, the memory cell can comprise a first electrode layer configured to generate ions in response to an electric field applied to the memory cell; a resistive ion migration layer at least in part permeable to migration of the ions within the resistive ion migration layer; a second electrode layer; and a substrate layer comprising a silicon wafer.
    Type: Grant
    Filed: July 25, 2014
    Date of Patent: November 22, 2016
    Assignee: CROSSBAR, INC.
    Inventors: Tanmay Kumar, Sung Hyun Jo
  • Patent number: 9472301
    Abstract: A method of programming a memory cell is provided. The memory cell includes a memory element having a first conductive material layer, a first dielectric material layer above the first conductive material layer, a second conductive material layer above the first dielectric material layer, a second dielectric material layer above the second conductive material layer, and a third conductive material layer above the second dielectric material layer. One or both of the first and second conductive material layers comprises a stack of a metal material layer and a highly doped semiconductor material layer. The memory cell has a first memory state upon fabrication corresponding to a first read current. The method includes applying a first programming pulse to the memory cell with a first current limit. The first programming pulse programs the memory cell to a second memory state that corresponds to a second read current greater than the first read current.
    Type: Grant
    Filed: July 20, 2015
    Date of Patent: October 18, 2016
    Assignee: SanDisk Technologies LLC
    Inventors: Abhijit Bandyopadhyay, Tanmay Kumar, Scott Brad Herner, Christopher J. Petti, Roy E. Scheuerlein
  • Publication number: 20160233422
    Abstract: A method for forming a non-volatile memory device includes disposing a junction layer comprising a doped silicon-bearing material in electrical contact with a first conductive material, forming a switching layer comprising an undoped amorphous silicon-bearing material upon at least a portion of the junction layer, disposing a layer comprising a non-noble metal material upon at least a portion of the switching layer, disposing an active metal layer comprising a noble metal material upon at least a portion of the layer, and forming a second conductive material in electrical contact with the active metal layer.
    Type: Application
    Filed: April 20, 2016
    Publication date: August 11, 2016
    Inventors: Sung Hyun Jo, Kuk-Hwan Kim, Tanmay Kumar
  • Patent number: 9373410
    Abstract: Providing for a memory cell capable of operating a one time programmable, multi-level cell memory is described herein. In some embodiments, a program signal having a first polarity and a first current compliance is applied to a memory cell. In an aspect, the memory cell is switched to a first program state from a non-program state in response to the first program signal. Furthermore, in an embodiment, an additional program signal having a second polarity is applied to the memory cell. In another aspect, the memory cell is switched to an additional program state different from the first program state in response to the additional program signal, wherein: the memory cell inherently resists switching back from the additional program state to the first program state, and the second polarity is opposite to the first polarity.
    Type: Grant
    Filed: September 5, 2014
    Date of Patent: June 21, 2016
    Assignee: CROSSBAR, INC.
    Inventor: Tanmay Kumar