Patents Assigned to Crossbar, Inc.
  • Patent number: 9460788
    Abstract: A non-volatile memory device is provided that uses one or more volatile elements. In some embodiments, the non-volatile memory device can include a resistive two-terminal selector that can be in a low resistive state or a high resistive state depending on the voltage being applied. A MOS (“metal-oxide-semiconductor”) transistor in addition to a capacitor or transistor acting as a capacitor can also be included. A first terminal of the capacitor can be connected to a voltage source, and the second terminal of the capacitor can be connected to the selector device. A floating gate of an NMOS transistor can be connected to the other side of the selector device, and a second NMOS transistor can be connected in series with the first NMOS transistor.
    Type: Grant
    Filed: May 20, 2015
    Date of Patent: October 4, 2016
    Assignee: Crossbar, Inc.
    Inventors: Hagop Nazarian, Sung Hyun Jo
  • Patent number: 9437814
    Abstract: During fabrication of a two-terminal memory device, a terminal (e.g., bottom terminal) can be formed. After formation of the terminal, a chemical mechanical planarization (CMP) process can be applied that, depending on the composition of the terminal, can cause damage that affect operating characteristics of the finished memory device or cell. In some embodiments, such damage can be removed by one or more post-CMP processes. In some embodiments, such damage can be mitigated so as to prevent the damage from occurring at all, by, e.g., forming a sacrificial layer atop the terminal prior to performing the CMP process. Thus, the sacrificial layer can operate to protect the terminal from damage resulting from the CMP process, with the remainder of the sacrificial layer being removed prior to completing the fabrication of the two-terminal memory device.
    Type: Grant
    Filed: August 29, 2014
    Date of Patent: September 6, 2016
    Assignee: Crossbar, Inc.
    Inventors: Harry Yue Gee, Majid Milani, Natividad Vasquez, Jr., Steven Patrick Maxwell, Sundar Narayanan
  • Patent number: 9437297
    Abstract: A method for programming a two terminal resistive memory device, the method includes applying a bias voltage to a first electrode of a resistive memory cell of the device; measuring a current flowing through the cell; and stopping the applying of the bias voltage if the measured current is equal to or greater than a predetermined value.
    Type: Grant
    Filed: July 15, 2014
    Date of Patent: September 6, 2016
    Assignee: Crossbar, Inc.
    Inventors: Hagop Nazarian, Sung Hyun Jo
  • Patent number: 9425237
    Abstract: Solid-state memory having a non-linear current-voltage (I-V) response is provided. By way of example, the solid-state memory can be a selector device. The selector device can be formed in series with a non-volatile memory device via a monolithic fabrication process. Further, the selector device can provide a substantially non-linear I-V response suitable to mitigate leakage current for the non-volatile memory device. In various disclosed embodiments, the series combination of the selector device and the non-volatile memory device can serve as one of a set of memory cells in a 1-transistor, many-resistor resistive memory cell array.
    Type: Grant
    Filed: December 31, 2014
    Date of Patent: August 23, 2016
    Assignee: Crossbar, Inc.
    Inventor: Sung Hyun Jo
  • Patent number: 9425046
    Abstract: Techniques for processing silicon germanium (SiGe) thin films to reduce surface roughness thereof are provided herein. In an aspect, a method is disclosed that includes depositing a silicon germanium (SiGe) material upon a surface of a substrate at or below about 450 degrees Celsius, the substrate having a plurality of CMOS devices therein and forming, from the deposited SiGe material, a SiGe material film, wherein the SiGe material film has a jagged surface comprising projections and indentations extended along a direction substantially perpendicular to the surface of the substrate. The method further includes performing a chemical mechanical planarization (CMP) process to the jagged surface of the SiGe material, and reducing variations between the projections and the indentions along the direction substantially perpendicular to the surface of the substrate, and transforming the jagged surface of the SiGe material into a relatively smooth surface, compared to the jagged surface.
    Type: Grant
    Filed: July 18, 2014
    Date of Patent: August 23, 2016
    Assignee: Crossbar, Inc.
    Inventors: Harry Yue Gee, Steven Patrick Maxwell, Natividad Vasquez, Jr., Sundar Narayanan
  • Patent number: 9412789
    Abstract: A memory device includes a first plurality of memory cells arranged in a first crossbar array, a first thickness of dielectric material overlying the first plurality of memory cells, and a second plurality of memory cells arranged in a second crossbar array overlying the first thickness of dielectric material. The memory device further includes a second thickness of dielectric material overlying the second plurality of memory cells. In a specific embodiment, the memory device further includes a Nth thickness of dielectric material overlying an Nth plurality of memory cells, where N is an integer ranging from 3 to 8.
    Type: Grant
    Filed: May 18, 2015
    Date of Patent: August 9, 2016
    Assignee: Crossbar, Inc.
    Inventor: Scott Brad Herner
  • Patent number: 9412790
    Abstract: A method for forming a resistive switching device. The method includes providing a substrate having a surface region and forming a first dielectric material overlying the surface region. A first wiring structure is formed overlying the first dielectric material. The method forms one or more first structure comprising a junction material overlying the first wiring structure. A second structure comprising a stack of material is formed overlying the first structure. The second structure includes a resistive switching material, an active conductive material overlying the resistive switching material, and a second wiring material overlying the active conductive material. The second structure is configured such that the resistive switching material is free from a coincident vertical sidewall region with the junction material.
    Type: Grant
    Filed: December 4, 2012
    Date of Patent: August 9, 2016
    Assignee: Crossbar, Inc.
    Inventors: Mark Harold Clark, Natividad Vasquez, Steven Maxwell
  • Patent number: 9406379
    Abstract: Providing for fabrication, construction, and/or assembly of a resistive random access memory (RRAM) cell is described herein. The RRAM cell can exhibit a non-linear current-voltage relationship. When arranged in a memory array architecture, these cells can significantly mitigate sneak path issues associated with conventional RRAM arrays.
    Type: Grant
    Filed: January 3, 2013
    Date of Patent: August 2, 2016
    Assignee: CROSSBAR, INC.
    Inventors: Sung Hyun Jo, Kuk-Hwan Kim
  • Patent number: 9401475
    Abstract: A method of depositing a silver layer includes forming a plurality of openings in a dielectric layer to expose a top surface of a structure comprising a resistive memory layer on top of a p-doped silicon-containing layer on top of a conductive structure, depositing a first metal layer comprising a tungsten layer overlying the top surface of the structure, wherein a first metal material of the first metal layer contacts a resistive memory material of the resistive memory layer and exposing the first metal layer in a bath comprising a solution of silver species having an alkaline pH for a predetermined time to form a silver metal layer from the silver species from the solution overlying the resistive memory material, wherein the silver species is reduced by the first metal material, and wherein the first metal material is solubilized while forming the silver metal layer.
    Type: Grant
    Filed: November 18, 2014
    Date of Patent: July 26, 2016
    Assignee: Crossbar, Inc.
    Inventors: Steven Patrick Maxwell, Sung-Hyun Jo, Scott Brad Herner
  • Patent number: 9397291
    Abstract: A two-terminal memory cell comprises a dual mode of operation in a unipolar mode and bipolar mode for a programming or On-state and for an erase or Off-state of the cell. The two-terminal memory cell is field programmable and can be flexibly designed or integrated into existing architecture. The two-terminal memory comprises a first electrode layer and a second electrode layer with a switching layer disposed between that has an electrical insulator material. A semiconductor layer is disposed between the switching layer and at least one of the first electrode or the second electrode. The switching layer generates a conductive path that is configured to be in a program state and an erase state, based on a bipolar mode and a unipolar mode.
    Type: Grant
    Filed: July 17, 2015
    Date of Patent: July 19, 2016
    Assignee: Crossbar, Inc.
    Inventor: Sung Hyun Jo
  • Patent number: 9385319
    Abstract: A resistive memory device includes a first metallic layer comprising a source of positive metallic ions, a switching media having an upper surface and a lower surface, wherein the upper surface is adjacent to the first metallic layer, wherein the switching media comprises conductive filaments comprising positive metallic ions from the source of positive metallic ions formed from the upper surface towards the lower surface, a semiconductor substrate, a second metallic layer disposed above the semiconductor substrate, a non-metallic conductive layer disposed above the second metallic layer, and an interface region between the non-metallic conductive layer and the switching media having a negative ionic charge.
    Type: Grant
    Filed: June 16, 2014
    Date of Patent: July 5, 2016
    Assignee: CROSSBAR, INC.
    Inventors: Hagop Nazarian, Sung Hyun Jo
  • 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
  • Patent number: 9362499
    Abstract: A method of forming a non-volatile memory device. The method forms a vertical stack of first polysilicon material and a second polysilicon material layer isolated by a dielectric material. The polysilicon material layers and the dielectric material are subjected to a first pattern and etch process to form a first wordline associated with a first switching device and a second wordline associated with a second switching device from the first polysilicon material layer, and a third wordline associated with a third switching device and a fourth wordline associated with a fourth switching device from the second polysilicon material. A via opening is formed to separate the first wordline from the second wordline and to separate the third wordline from the fourth wordline. An amorphous silicon switching material is deposited conformably overlying the via opening. A metal material fills the via opening and connects to a common bitline.
    Type: Grant
    Filed: March 10, 2015
    Date of Patent: June 7, 2016
    Assignee: Crossbar, Inc.
    Inventors: Harry Gee, Sung Hyun Jo, Hagop Nazarian, Scott Brad Herner
  • Patent number: 9355717
    Abstract: Providing a memory array having an embedded source line driver is described herein. By way of example, the source line driver can comprise a dissipation line and a switching component that connects or disconnects the dissipation line with a source line of the memory array. When the switching component is activated, the dissipation line can provide a low resistance path from the source line to ground, as one example. Disclosed are circuits in which one or more dissipation lines are situated along a length of the source line, facilitating reduced variation in electrical characteristics (e.g., voltage drop) along the source line, improving regularity of memory operations for memory cells associated with the source line.
    Type: Grant
    Filed: August 27, 2014
    Date of Patent: May 31, 2016
    Assignee: Crossbar, Inc.
    Inventors: Hagop Nazarian, Sang Nguyen
  • Patent number: 9343668
    Abstract: Providing for two-terminal memory cell structures and fabrication that can be achieved with a relatively low temperature process(es) is described herein. By way of example, disclosed two-terminal memory cells can be formed at least in part as a continuous deposition, potentially yielding improved efficiency in manufacturing. Furthermore, various embodiments can be compatible with some existing complementary metal oxide semiconductor fabrication processes, reducing or avoiding retooling overhead that might be associated with modifying existing fabrication processes in favor of other two-terminal memory cell fabrication techniques.
    Type: Grant
    Filed: March 14, 2013
    Date of Patent: May 17, 2016
    Assignee: CROSSBAR, INC.
    Inventors: Steve Maxwell, Sundar Narayanan, Sung Hyun Jo, Tanmay Kumar
  • Patent number: 9336876
    Abstract: Providing for improved programming techniques for endurance and memory retention in two-terminal memory is described herein. In some embodiments, a programming pulse can be configured to provide a minimum pulse time over which a program signal is applied to a two-terminal memory cell, following programming of the two-terminal memory cell. This minimum pulse time can help to stabilize the program state of the two-terminal memory cell, improving stability of the program state (e.g., related to memory retention) and overall increased endurance (e.g., in program cycles) of the two-terminal memory cell. The minimum pulse time can be initiated separately to a programming pulse, or can be integrated as part of the program pulse, in various embodiments. In some embodiments, current compliance or voltage control can be implemented in conjunction with providing programming and minimum pulse time functionality.
    Type: Grant
    Filed: March 14, 2014
    Date of Patent: May 10, 2016
    Assignee: Crossbar, Inc.
    Inventors: Tanmay Kumar, Layne Armijo, Sung Hyun Jo
  • Patent number: 9324942
    Abstract: Providing for a solid state memory cell having a resistive switching memory cell with rectifier characteristics is described herein. By way of example, the solid state memory cell can have one or more layers creating a resistive switching device capable of achieving and maintaining different electrical resistances in response to different voltages applied to the solid state memory cell. Moreover, the solid state memory cell can comprise two or more layers creating a solid state diode device electrically in series with the resistive switching device. The solid state diode device can be configured to permit very low current through the solid state memory cell at voltages less than a breakdown voltage or reverse breakdown voltage. The rectifier characteristics can mitigate sneak path currents in a crossbar memory array, or similar array, facilitating greater sensing margin, reduced likelihood of memory errors, greater die concentration, fast switching times, and other benefits.
    Type: Grant
    Filed: January 31, 2013
    Date of Patent: April 26, 2016
    Assignee: CROSSBAR, INC.
    Inventors: Hagop Nazarian, Tanmay Kumar, Sung Hyun Jo
  • Patent number: 9312483
    Abstract: A method of forming a resistive switching device includes forming a wiring structure over a first dielectric and substrate, forming a junction layer over the wiring structure, forming a resistive switching layer over the junction layer, forming an active metal over the resistive switching layer, forming a tungsten layer over the active metal, forming a barrier layer over the tungsten, depositing a mask over the barrier layer, etching the barrier layer to form a hard mask, etching the junction layer, the resistive switching layer, the active metal layer, and the adhesion layer using the hard mask to form a stack of material, while the adhesion layer maintains adhesion between the barrier layer and the active metal and while side walls of the stack of material have reduced contaminants and have reduced gap regions between the barrier layer and the resistive switching layer.
    Type: Grant
    Filed: September 24, 2012
    Date of Patent: April 12, 2016
    Assignee: CROSSBAR, INC.
    Inventor: Steven Patrick Maxwell
  • Patent number: 9269897
    Abstract: A method of forming a resistive device includes forming a first wiring layer overlying a first dielectric on top of a substrate, forming a junction material, patterning the first wiring layer and junction material to expose a portion of the first dielectric, forming a second dielectric over the patterned first wiring layer, forming an opening in the second dielectric to expose a portion of the junction material, forming a resistive switching material over the portion of the junction material in the opening, the resistive switching material having an intrinsic semiconductor characteristic, forming a conductive material over the resistive switching material, etching the conductive material and the resistive switching material to expose respective sidewalls of the resistive switching material and the conductive material, and the second dielectric, and forming a second wiring layer over the conductive material in contact with the respective sidewalls and the second dielectric.
    Type: Grant
    Filed: June 20, 2014
    Date of Patent: February 23, 2016
    Assignee: Crossbar, Inc.
    Inventor: Mark Harold Clark
  • Patent number: 9269898
    Abstract: Providing for low temperature deposition of silicon-based electrical conductor for solid state memory is described herein. In various disclosed embodiments, the silicon-based conductor can form an electrode of a memory cell, an interconnect between conductive components of an electronic device, a conductive via, a wire, and so forth. Moreover, the silicon-based electrical conductor can be formed as part of a monolithic process incorporating complementary metal oxide semiconductor (CMOS) device fabrication. In particular embodiments, the silicon-based electrical conductor can be a p-type silicon germanium compound, that is activated upon deposition at temperatures compatible with CMOS device fabrication.
    Type: Grant
    Filed: July 25, 2014
    Date of Patent: February 23, 2016
    Assignee: Crossbar, Inc.
    Inventors: Steven Patrick Maxwell, Kuk-Hwan Kim, Sung Hyun Jo