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: 20130003436
    Abstract: A non-volatile memory device includes a resistive switching device having a first electrode, a second electrode, and a resistive switching element, wherein the resistive switching element comprises a silicon material disposed in an overlapping region between the first electrode and the second electrode, wherein the second electrode comprises at least a metal material physically and electrically in contact with the resistive switching material, wherein the resistive switching element is characterized by a resistance depending on an electric field in the resistive switching element, and a non-linear device coupled between the first electrode and the resistive switching element, wherein the non-linear device is configured to conduct electric current when a voltage greater than a first voltage is applied to the second electrode, wherein the resistive switching device is configured to change from a first state to a second state in response to the first voltage.
    Type: Application
    Filed: June 30, 2011
    Publication date: January 3, 2013
    Applicant: Crossbar, Inc.
    Inventor: Tanmay KUMAR
  • Publication number: 20120315725
    Abstract: This disclosure provides a method of fabricating a semiconductor device layer and associated memory cell structures. By performing a surface treatment process (such as ion bombardment) of a semiconductor device layer to create defects having a deliberate depth profile, one may create multistable memory cells having more consistent electrical parameters. For example, in a resistive-switching memory cell, one may obtain a tighter distribution of set and reset voltages and lower forming voltage, leading to improved device yield and reliability. In at least one embodiment, the depth profile is selected to modulate the type of defects and their influence on electrical properties of a bombarded metal oxide layer and to enhance uniform defect distribution.
    Type: Application
    Filed: August 23, 2012
    Publication date: December 13, 2012
    Applicant: Intermolecular, Inc.
    Inventors: Michael Miller, Prashant Phatak, Tony Chiang, Xiyang Chen, April Schricker, Tanmay Kumar
  • Publication number: 20120280202
    Abstract: A monolithic three dimensional memory array is provided that includes a first memory level formed above a substrate, and a second memory level monolithically formed above the first memory level. The first memory level includes a first plurality of substantially parallel, substantially coplanar conductors extending in a first direction, a second plurality of substantially parallel, substantially coplanar conductors extending in a second direction, the second direction different from the first direction, the second conductors above the first conductors, and a first plurality of devices. Each of the first plurality of devices is disposed between one of the first conductors and one of the second conductors, and includes a resistivity-switching binary metal oxide or nitride compound and a silicon, germanium, or silicon-germanium alloy resistor of a single conductivity type. Numerous other aspects are provided.
    Type: Application
    Filed: July 20, 2012
    Publication date: November 8, 2012
    Inventors: Tanmay Kumar, S. Brad Herner
  • Patent number: 8274066
    Abstract: This disclosure provides a method of fabricating a semiconductor device layer and associated memory cell structures. By performing a surface treatment process (such as ion bombardment) of a semiconductor device layer to create defects having a deliberate depth profile, one may create multistable memory cells having more consistent electrical parameters. For example, in a resistive-switching memory cell, one may obtain a tighter distribution of set and reset voltages and lower forming voltage, leading to improved device yield and reliability. In at least one embodiment, the depth profile is selected to modulate the type of defects and their influence on electrical properties of a bombarded metal oxide layer and to enhance uniform defect distribution.
    Type: Grant
    Filed: October 4, 2011
    Date of Patent: September 25, 2012
    Assignee: Intermolecular, Inc.
    Inventors: Michael Miller, Prashant Phatak, Tony Chiang, Xiyang Chen, April Schricker, Tanmay Kumar
  • Patent number: 8227787
    Abstract: In the present invention, a metal oxide or nitride compound which is a wide-band-gap semiconductor abuts a silicon, germanium, or alloy of silicon and/or germanium of the opposite conductivity type to form a p-n heterojunction. This p-n heterojunction can be used to advantage in various devices. In preferred embodiments, one terminal of a vertically oriented p-i-n heterojunction diode is a metal oxide or nitride layer, while the rest of the diode is formed of a silicon or silicon-germanium resistor. For example, a diode may include a heavily doped n-type silicon region, an intrinsic silicon region, and a nickel oxide layer serving as the p-type terminal. Many of these metal oxides and nitrides exhibit resistivity-switching behavior, and such a heterojunction diode can be used in a nonvolatile memory cell, for example in a monolithic three dimensional memory array.
    Type: Grant
    Filed: January 17, 2011
    Date of Patent: July 24, 2012
    Assignee: SanDisk 3D LLC
    Inventors: Tanmay Kumar, S. Brad Herner
  • Publication number: 20120032133
    Abstract: This disclosure provides a method of fabricating a semiconductor device layer and associated memory cell structures. By performing a surface treatment process (such as ion bombardment) of a semiconductor device layer to create defects having a deliberate depth profile, one may create multistable memory cells having more consistent electrical parameters. For example, in a resistive-switching memory cell, one may obtain a tighter distribution of set and reset voltages and lower forming voltage, leading to improved device yield and reliability. In at least one embodiment, the depth profile is selected to modulate the type of defects and their influence on electrical properties of a bombarded metal oxide layer and to enhance uniform defect distribution.
    Type: Application
    Filed: October 4, 2011
    Publication date: February 9, 2012
    Applicant: INTERMOLECULAR, INC.
    Inventors: Michael Miller, Prashant Phatak, Tony Chiang, Xiying Chen, April Schricker, Tanmay Kumar
  • Patent number: 8102694
    Abstract: A nonvolatile memory device includes at least one nonvolatile memory cell which comprises a silicon, germanium or silicon-germanium diode which is doped with at least one of carbon or nitrogen in a concentration greater than an unavoidable impurity level concentration.
    Type: Grant
    Filed: June 25, 2007
    Date of Patent: January 24, 2012
    Assignee: SanDisk 3D LLC
    Inventors: S. Brad Herner, Mark H. Clark, Tanmay Kumar
  • Patent number: 8072791
    Abstract: A method of making a nonvolatile memory device includes forming a first electrode, forming at least one nonvolatile memory cell comprising a silicon, germanium or silicon-germanium diode, doping the diode with at least one of nitrogen or carbon, and forming a second electrode over the at least one nonvolatile memory cell.
    Type: Grant
    Filed: June 25, 2007
    Date of Patent: December 6, 2011
    Assignee: SanDisk 3D LLC
    Inventors: S. Brad Herner, Mark H. Clark, Tanmay Kumar
  • Patent number: 8062918
    Abstract: This disclosure provides a method of fabricating a semiconductor device layer and associated memory cell structures. By performing a surface treatment process (such as ion bombardment) of a semiconductor device layer to create defects having a deliberate depth profile, one may create multistable memory cells having more consistent electrical parameters. For example, in a resistive-switching memory cell, one may obtain a tighter distribution of set and reset voltages and lower forming voltage, leading to improved device yield and reliability. In at least one embodiment, the depth profile is selected to modulate the type of defects and their influence on electrical properties of a bombarded metal oxide layer and to enhance uniform defect distribution.
    Type: Grant
    Filed: December 29, 2008
    Date of Patent: November 22, 2011
    Assignee: Intermolecular, Inc.
    Inventors: Michael Miller, Prashant Phatak, Tony Chiang, Xiying Chen, April Schricker, Tanmay Kumar
  • Patent number: 8048474
    Abstract: A method of making a nonvolatile memory cell includes forming a steering element and forming a carbon resistivity switching material storage element by coating a carbon containing colloid.
    Type: Grant
    Filed: August 7, 2008
    Date of Patent: November 1, 2011
    Assignee: SanDisk 3D LLC
    Inventors: Tanmay Kumar, Er-Xuan Ping, Alper Ilkbahar
  • Patent number: 8023310
    Abstract: A nonvolatile memory cell includes a storage element, the storage element comprising a carbon material, a steering element located in series with the storage element, and a metal silicide layer located adjacent to the carbon material. A method of making a device includes forming a metal silicide over a silicon layer, forming a carbon layer over the metal silicide layer, forming a barrier layer over the carbon layer, and patterning the carbon layer, the metal silicide layer, and the silicon layer to form an array of pillars.
    Type: Grant
    Filed: January 14, 2009
    Date of Patent: September 20, 2011
    Assignee: SanDisk 3D LLC
    Inventors: Chu-Chen Fu, Tanmay Kumar, Er-Xuan Ping, Huiwan Xu
  • Patent number: 8008700
    Abstract: A nonvolatile memory device includes at least one memory cell which comprises a first diode portion, a second diode portion and an antifuse separating the first diode portion from the second diode portion.
    Type: Grant
    Filed: June 28, 2007
    Date of Patent: August 30, 2011
    Assignee: SanDisk 3D LLC
    Inventors: Tanmay Kumar, S. Brad Herner
  • Patent number: 7982273
    Abstract: A monolithic three dimensional semiconductor device structure includes a first layer including a first occurrence of a first reference mark at a first location, and a second layer including a second occurrence of the first reference mark at a second location, wherein the second location is substantially directly above the first location. The device structure also includes an intermediate layer between the first layer and the second layer, the intermediate layer including a blocking structure, wherein the blocking structure is vertically interposed between the first occurrence of the first reference mark and the second occurrence of the first reference mark. Other aspects are also described.
    Type: Grant
    Filed: May 22, 2009
    Date of Patent: July 19, 2011
    Assignee: SanDisk 3D LLC
    Inventors: Yung-Tin Chen, Christopher J. Petti, Steven J. Radigan, Tanmay Kumar
  • Patent number: 7978496
    Abstract: A nonvolatile memory cell includes a steering element located in series with a storage element, where the storage element comprises a carbon material. A method of programming the cell includes applying a reset pulse to change a resistivity state of the carbon material from a first state to a second state which is higher than the first state, and applying a set pulse to change a resistivity state of the carbon material from the second state to a third state which is lower than the second state. A fall time of the reset pulse is shorter than a fall time of the set pulse.
    Type: Grant
    Filed: December 18, 2008
    Date of Patent: July 12, 2011
    Assignee: SanDisk 3D LLC
    Inventors: Tanmay Kumar, Xiying Chen
  • Patent number: 7969011
    Abstract: A metal-insulator diode is disclosed. In one aspect, the metal-insulator diode comprises first and second electrode and first and second insulators arraigned as follows. An insulating region has a trench formed therein. The trench has a bottom and side walls. The first electrode, which comprises a first metal, is on the side walls and over the bottom of the trench. A first insulator has a first interface with the first electrode. At least a portion of the first insulator is within the trench. A second insulator has a second interface with the first insulator. At least a portion of the second insulator is within the trench. The second electrode, which comprises a second metal, is in contact with the second insulator. The second electrode at least partially fills the trench.
    Type: Grant
    Filed: September 29, 2008
    Date of Patent: June 28, 2011
    Assignee: SanDisk 3D LLC
    Inventors: Deepak C. Sekar, Tanmay Kumar, Peter Rabkin, Er-Xuan Ping, Xiying Chen
  • Publication number: 20110114913
    Abstract: In the present invention, a metal oxide or nitride compound which is a wide-band-gap semiconductor abuts a silicon, germanium, or alloy of silicon and/or germanium of the opposite conductivity type to form a p-n heterojunction. This p-n heterojunction can be used to advantage in various devices. In preferred embodiments, one terminal of a vertically oriented p-i-n heterojunction diode is a metal oxide or nitride layer, while the rest of the diode is formed of a silicon or silicon-germanium resistor. For example, a diode may include a heavily doped n-type silicon region, an intrinsic silicon region, and a nickel oxide layer serving as the p-type terminal. Many of these metal oxides and nitrides exhibit resistivity-switching behavior, and such a heterojunction diode can be used in a nonvolatile memory cell, for example in a monolithic three dimensional memory array.
    Type: Application
    Filed: January 17, 2011
    Publication date: May 19, 2011
    Inventors: Tanmay Kumar, S. Brad Herner
  • Patent number: 7944728
    Abstract: A method of programming a memory cell comprises applying a reverse bias to the memory cell using a temporary resistor in series with the memory cell. The memory cell comprises a diode and a resistivity switching material element in series. The state of the resistivity switching material element changes from a first initial state to a second state different from the first state.
    Type: Grant
    Filed: December 19, 2008
    Date of Patent: May 17, 2011
    Assignee: SanDisk 3D LLC
    Inventors: Yibo Nian, Tanmay Kumar, Roy E. Scheuerlein
  • Patent number: 7915163
    Abstract: The invention provides for polysilicon vias connecting conductive polysilicon layers formed at different heights. Polysilicon vias are advantageously used in a monolithic three dimensional memory array of charge storage transistors. Polysilicon vias according to the present invention can be used, for example, to connect the channel layer of a first device level of charge storage transistor memory cells to the channel layer of a second device layer of such cells formed above the first device level. Similarly, vias according to the present invention can be used to connect the wordline of a first device level of charge storage transistor memory cells to the channel layer of a second device layer of such cells.
    Type: Grant
    Filed: June 22, 2009
    Date of Patent: March 29, 2011
    Assignee: SanDisk 3D LLC
    Inventors: Michael W. Konevecki, Usha Raghuram, Maitreyee Mahajani, Sucheta Nallamothu, Andrew J. Walker, Tanmay Kumar
  • Patent number: 7915094
    Abstract: A method of making a nonvolatile memory device includes fabricating a diode in a low resistivity, programmed state without an electrical programming step. The memory device includes at least one memory cell. The memory cell is constituted by the diode and electrically conductive electrodes contacting the diode.
    Type: Grant
    Filed: October 2, 2009
    Date of Patent: March 29, 2011
    Assignee: SanDisk 3D LLC
    Inventors: Tanmay Kumar, S. Brad Herner
  • Patent number: 7915164
    Abstract: The invention provides for polysilicon vias connecting conductive polysilicon layers formed at different heights. Polysilicon vias are advantageously used in a monolithic three dimensional memory array of charge storage transistors. Polysilicon vias according to the present invention can be used, for example, to connect the channel layer of a first device level of charge storage transistor memory cells to the channel layer of a second device layer of such cells formed above the first device level. Similarly, vias according to the present invention can be used to connect the wordline of a first device level of charge storage transistor memory cells to the channel layer of a second device layer of such cells.
    Type: Grant
    Filed: October 4, 2010
    Date of Patent: March 29, 2011
    Assignee: SanDisk 3D LLC
    Inventors: Michael W. Konevecki, Usha Raghuram, Maitreyee Mahajani, Sucheta Nallamothu, Andrew J. Walker, Tanmay Kumar