Patents Assigned to Sandisk 3D LLC
  • Patent number: 9012879
    Abstract: A nonvolatile memory device contains a resistive switching memory element with improved device switching performance and life and methods for forming the same. The nonvolatile memory device has a first layer on a substrate, a resistive switching layer on the first layer, and a second layer. The resistive switching layer is disposed between the first layer and the second layer and the resistive switching layer comprises a material having the same morphology as the top surface of the first layer. A method of forming a nonvolatile memory element in a ReRAM device includes forming a resistive switching layer on a first layer and forming a second layer, so that the resistive switching layer is disposed between the first layer and the second layer. The resistive switching layer comprises a material formed with the same morphology as the top surface of the first layer.
    Type: Grant
    Filed: September 22, 2014
    Date of Patent: April 21, 2015
    Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLC
    Inventors: Federico Nardi, Yun Wang
  • Patent number: 9007810
    Abstract: FORMING reversible resistivity-switching elements is described herein. The FORMING voltage may be halted if the current through the memory cell reaches some reference current. The reference current may depend on how many groups of memory cells have been FORMED. This can help to increase the accuracy of determining when to halt the FORMING voltage. After the FORMING voltage is applied, a RESET voltage may be applied to those memory cells that have a resistance that is lower than a reference resistance to raise the resistance of those memory cells. By raising the resistance, the leakage current of these memory cells when other groups are programmed may be less. This, in turn, helps to prevent FORMING of the other groups from slowing down. A reason why this helps to prevent the slowdown is that the FORMING voltage may be kept near a desired level.
    Type: Grant
    Filed: February 28, 2013
    Date of Patent: April 14, 2015
    Assignee: SanDisk 3D LLC
    Inventor: Chang Siau
  • Patent number: 9006696
    Abstract: Provided are resistive random access memory (ReRAM) cells and methods of fabricating thereof. A ReRAM cell includes an embedded resistor and resistive switching layer connected in series. The embedded resistor prevents excessive electrical currents through the resistive switching layer, especially when the resistive switching layer is switched into its low resistive state, thereby preventing over-programming. The embedded resistor includes aluminum, nitrogen, and one or more additional metals (other than aluminum). The concentration of each component is controlled to achieve desired resistivity and stability of the embedded resistor. In some embodiments, the resistivity ranges from 0.1 Ohm-centimeter to 40 Ohm-centimeter and remains substantially constant while applying an electrical field of up 8 mega-Volts/centimeter to the embedded resistor. The embedded resistor may be made from an amorphous material, and the material is operable to remain amorphous even when subjected to typical annealing conditions.
    Type: Grant
    Filed: September 8, 2014
    Date of Patent: April 14, 2015
    Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLC
    Inventors: Mihir Tendulkar, Randall J. Higuchi, Chien-Lan Hsueh
  • Patent number: 9006026
    Abstract: Embodiments of the invention generally relate to nonvolatile memory devices and methods for manufacturing such memory devices. The methods for forming improved memory devices, such as a ReRAM cells, provide optimized, atomic layer deposition (ALD) processes for forming a metal oxide film stack which contains at least one hard metal oxide film (e.g., metal is completely oxidized or substantially oxidized) and at least one soft metal oxide film (e.g., metal is less oxidized than hard metal oxide). The soft metal oxide film is less electrically resistive than the hard metal oxide film since the soft metal oxide film is less oxidized or more metallic than the hard metal oxide film. In one example, the hard metal oxide film is formed by an ALD process utilizing ozone as the oxidizing agent while the soft metal oxide film is formed by another ALD process utilizing water vapor as the oxidizing agent.
    Type: Grant
    Filed: August 22, 2014
    Date of Patent: April 14, 2015
    Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLC
    Inventors: Zhendong Hong, Vidyut Gopal, Imran Hashim, Randall J. Higuchi, Tim Minvielle, Hieu Pham, Takeshi Yamaguchi
  • Patent number: 9006795
    Abstract: A memory cell is provided that includes a diode and a resistance-switching material layer coupled in series with the diode. The resistance-switching material layer has a thickness between 20 and 65 angstroms. Other aspects are also provided.
    Type: Grant
    Filed: February 14, 2014
    Date of Patent: April 14, 2015
    Assignee: SanDisk 3D LLC
    Inventors: Xiaoyu Yang, Roy E. Scheuerlein, Feng Li, Albert T. Meeks
  • Patent number: 9001554
    Abstract: Provided are resistive random access memory (ReRAM) cells, each having three or more resistive states and being capable of storing multiple bits of data, as well as methods of fabricating and operating such ReRAM cells. Such ReRAM cells or, more specifically, their resistive switching layer have wide range of resistive states and are capable of being very conductive (e.g., about 1 kOhm) in one state and very resistive (e.g., about 1 MOhm) in another state. In some embodiments, a resistance ratio between resistive states may be between 10 and 1,000 even up to 10,000. The resistive switching layers also allow establishing stable and distinct intermediate resistive states that may be assigned different data values. These layers may be configured to switching between their resistive states using fewer programming pulses than conventional systems by using specific materials, switching pluses, and resistive state threshold.
    Type: Grant
    Filed: January 10, 2013
    Date of Patent: April 7, 2015
    Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLC
    Inventors: Imran Hashim, Ryan C. Clarke, Nan Lu, Tim Minvielle, Takeshi Yamaguchi
  • Patent number: 9000407
    Abstract: A switching element for resistive-switching memory (ReRAM) provides a controllable, consistent filament break-point at an abrupt structural discontinuity between a layer of high-k high-ionicity variable-resistance (VR) material and a layer of low-k low-ionicity VR material. The high-ionicity layer may be crystalline and the low-ionicity layer may be amorphous. The consistent break-point and characteristics of the low-ionicity layer facilitate lower-power operation. The defects (e.g., oxygen or nitrogen vacancies) that constitute the filament originate either in the high-ionicity VR layer or in a source electrode. The electrode nearest to the low-ionicity layer may be intrinsically inert or may be rendered effectively inert. Some electrodes are rendered effectively inert by the creation of the low-ionicity layer over the electrode.
    Type: Grant
    Filed: May 28, 2013
    Date of Patent: April 7, 2015
    Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLC
    Inventors: Yun Wang, Tony P. Chiang, Dipankar Pramanik
  • Patent number: 8995169
    Abstract: Operating ReRAM memory is disclosed herein. The memory cells may be trained prior to initially programming them. The training may help to establish a percolation path. In some aspects, a transistor limits current of the memory cell when training and programming. A higher current limit is used during training, which conditions the memory cell for better programming. The non-memory may be operated in unipolar mode. The memory cells can store multiple bits per memory cell. A memory cell can be SET directly from its present state to one at least two data states away. A memory cell can be RESET directly to the state having the next highest resistance. Program conditions, such as pulse width and/or magnitude, may depend on the state to which the memory cell is being SET. A higher energy can be used for programming higher current states.
    Type: Grant
    Filed: September 12, 2013
    Date of Patent: March 31, 2015
    Assignee: SanDisk 3D LLC
    Inventors: Abhijit Bandyopadhyay, Roy E. Scheuerlein, Chandrasekhar R. Gorla, Brian Le
  • Patent number: 8995172
    Abstract: Embodiments of the invention generally include a method of forming a nonvolatile memory device that contains a resistive switching memory element that has an improved device switching performance and lifetime, due to the addition of a current limiting component disposed therein. In one embodiment, the current limiting component comprises at least one layer of resistive material that is configured to improve the switching performance and lifetime of the formed resistive switching memory element. The electrical properties of the formed current limiting layer, or resistive layer, are configured to lower the current flow through the variable resistance layer during the logic state programming steps (i.e., “set” and “reset” steps) by adding a fixed series resistance in the formed resistive switching memory element found in the nonvolatile memory device.
    Type: Grant
    Filed: February 21, 2014
    Date of Patent: March 31, 2015
    Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLC
    Inventors: Yun Wang, Tony P. Chiang, Imran Hashim
  • Patent number: 8995166
    Abstract: A resistor array for multi-bit data storage without the need to increase the size of a memory chip or scale down the feature size of a memory cell contained within the memory chip is provided. The resistor array incorporates a number of discrete resistive elements to be selectively connected, in different series combinations, to at least one memory cell or memory device. In one configuration, by connecting each memory cell or device with at least one resistor array, a resistive switching layer found in the resistive switching memory element of the connected memory device is capable of being at multiple resistance states for storing multiple bits of digital information. During device programming operations, when a desired series combination of the resistive elements within the resistor array is selected, the resistive switching layer in the connected memory device can be in a desired resistance state.
    Type: Grant
    Filed: December 20, 2012
    Date of Patent: March 31, 2015
    Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLC
    Inventors: Dipankar Pramanik, David E Lazovsky, Tim Minvielle, Takeshi Yamaguchi
  • Patent number: 8987119
    Abstract: A method of making a semiconductor device includes providing an insulating layer containing a plurality of openings, forming a first semiconductor layer in the plurality of openings in the insulating layer and over the insulating layer, and removing a first portion of the first semiconductor layer, such that first conductivity type second portions of the first semiconductor layer remain in lower portions of the plurality of openings in the insulating layer, and upper portions of the plurality of openings in the insulating layer remain unfilled. The method also includes forming a second semiconductor layer in the upper portions of the plurality of openings in the insulating layer and over the insulating layer, and removing a first portion of the second semiconductor layer located over the insulating layer.
    Type: Grant
    Filed: February 14, 2011
    Date of Patent: March 24, 2015
    Assignee: Sandisk 3D LLC
    Inventors: Vance Dunton, S. Brad Herner, Paul Wai Kie Poon, Chuanbin Pan, Michael Chan, Michael Konevecki, Usha Raghuram
  • Patent number: 8988936
    Abstract: Methods for performing parallel voltage and current compensation during reading and/or writing of memory cells in a memory array are described. In some embodiments, the compensation may include adjusting a bit line voltage and/or bit line reference current applied to a memory cell based on a memory array zone, a bit line layer, and a memory cell direction associated with the memory cell. The compensation may include adjusting the bit line voltage and/or bit line reference current on a per memory cell basis depending on memory cell specific characteristics. In some embodiments, a read/write circuit for reading and/or writing a memory cell may select a bit line voltage from a plurality of bit line voltage options to be applied to the memory cell based on whether the memory cell has been characterized as a strong, weak, or typical memory cell.
    Type: Grant
    Filed: October 4, 2014
    Date of Patent: March 24, 2015
    Assignee: SanDisk 3D LLC
    Inventors: Yingchang Chen, Pankaj Kalra, Chandrasekhar Gorla
  • Patent number: 8987865
    Abstract: A resistor structure incorporated into a resistive switching memory cell or device to form memory devices with improved device performance and lifetime is provided. The resistor structure may be a two-terminal structure designed to reduce the maximum current flowing through a memory device. A method is also provided for making such memory device. The method includes depositing a resistor structure and depositing a variable resistance layer of a resistive switching memory cell of the memory device, where the resistor structure is disposed in series with the variable resistance layer to limit the switching current of the memory device. The incorporation of the resistor structure is very useful in obtaining desirable levels of device switching currents that meet the switching specification of various types of memory devices. The memory devices may be formed as part of a high-capacity nonvolatile memory integrated circuit, which can be used in various electronic devices.
    Type: Grant
    Filed: May 27, 2014
    Date of Patent: March 24, 2015
    Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLC
    Inventors: Dipankar Pramanik, Tony P. Chiang, Mankoo Lee
  • Patent number: 8987046
    Abstract: Non-volatile storage elements having a reversible resistivity-switching element and techniques for fabricating the same are disclosed herein. The reversible resistivity-switching element may be formed by depositing an oxygen diffusion resistant material (e.g., heavily doped Si, W, WN) over the top electrode. A trap passivation material (e.g., fluorine, nitrogen, hydrogen, deuterium) may be incorporated into one or more of the bottom electrode, a metal oxide region, or the top electrode of the reversible resistivity-switching element. One embodiment includes a reversible resistivity-switching element having a bi-layer capping layer between the metal oxide and the top electrode. Fabricating the device may include depositing (un-reacted) titanium and depositing titanium oxide in situ without air break. One embodiment includes incorporating titanium into the metal oxide of the reversible resistivity-switching element.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: March 24, 2015
    Assignee: SanDisk 3D LLC
    Inventors: Deepak C. Sekar, Franz Kreupl, Raghuveer S. Makala, Peter Rabkin
  • Patent number: 8987697
    Abstract: Embodiments of the invention include nonvolatile memory elements and memory devices comprising the nonvolatile memory elements. Methods for forming the nonvolatile memory elements are also disclosed. The nonvolatile memory element comprises a first electrode layer, a second electrode layer, and a plurality of layers of an oxide disposed between the first and second electrode layers. One of the oxide layers has linear resistance and substoichiometric composition, and the other oxide layer has bistable resistance and near-stoichiometric composition. Preferably, the sum of the two oxide layer thicknesses is between about 20 ? and about 100 ?, and the oxide layer with bistable resistance has a thickness between about 25% and about 75% of the total thickness. In one embodiment, the oxide layers are formed using reactive sputtering in an atmosphere with controlled flows of argon and oxygen.
    Type: Grant
    Filed: April 14, 2014
    Date of Patent: March 24, 2015
    Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLC
    Inventors: Hieu Pham, Vidyut Gopal, Imran Hashim, Tim Minvielle, Yun Wang, Takeshi Yamaguchi, Hong Sheng Yang
  • Patent number: 8982597
    Abstract: The system includes multiple sets of local data lines in one or more routing metal layers below the three-dimensional memory array and multiple sets of global data lines in one or more top metal layers above the three-dimensional memory array. Each set of one or more blocks include one set of the local data lines. Each bay includes one set of global data lines that connect to the group of sense amplifiers associated with the blocks of the respective bay. Each block includes a subset of first selection circuits for selectively coupling a subset of array lines of the first type to respective local data lines. Each block includes a subset of second selection circuits for selectively coupling a subset of the respective local data lines to global data lines associated with a respective bay.
    Type: Grant
    Filed: January 31, 2012
    Date of Patent: March 17, 2015
    Assignee: Sandisk 3D LLC
    Inventors: Tianhong Yan, Luca Fasoli
  • Patent number: 8981347
    Abstract: A method of forming a memory cell is provided. The method includes forming a steering element pillar having a first stiffness and a sidewall, forming a sidewall collar along at least a portion of the sidewall of the steering element pillar, the sidewall collar having a second stiffness, wherein the second stiffness is greater than the first stiffness, and forming a memory element coupled to the steering element pillar. Numerous other aspects are provided.
    Type: Grant
    Filed: February 17, 2014
    Date of Patent: March 17, 2015
    Assignee: SanDisk 3D LLC
    Inventor: Scott Brad Herner
  • Patent number: 8980766
    Abstract: Provided are methods of forming nonvolatile memory elements using atomic layer deposition techniques, in which at least two different layers of a memory element are deposited sequentially and without breaking vacuum in a deposition chamber. This approach may be used to prevent oxidation of various materials used for electrodes without a need for separate oxygen barrier layers. A combination of signal lines and resistive switching layers may be used to cap the electrodes and to minimize their oxidation. As such, fewer layers are needed in a memory element. Furthermore, atomic layer deposition allows more precise control of electrode thicknesses. In some embodiments, a thickness of an electrode may be less than 50 Angstroms. Overall, atomic layer deposition of electrodes and resistive switching layers lead to smaller thicknesses of entire memory elements making them more suitable for low aspect ratio features of advanced nodes.
    Type: Grant
    Filed: July 10, 2014
    Date of Patent: March 17, 2015
    Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLC
    Inventors: Yun Wang, Tony P. Chiang, Tim Minvielle, Takeshi Yamaguchi
  • Patent number: 8981329
    Abstract: Embodiments of the invention include a nonvolatile memory device that contains nonvolatile resistive random access memory device with improved device performance and lifetime. In some embodiments, nonvolatile resistive random access memory device includes a diode, a metal silicon nitride embedded resistor, and a resistive switching layer disposed between a first electrode layer and a second electrode layer. In some embodiments, the method of forming a resistive random access memory device includes forming a diode, forming a metal silicon nitride embedded resistor, forming a first electrode layer, forming a second electrode layer, and forming a resistive switching layer disposed between the first electrode layer and the second electrode layer.
    Type: Grant
    Filed: November 20, 2014
    Date of Patent: March 17, 2015
    Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLC
    Inventors: Mihir Tendulkar, David Chi
  • Patent number: 8981457
    Abstract: There is provided a monolithic three dimensional array of charge storage devices which includes a plurality of device levels, wherein at least one surface between two successive device levels is planarized by chemical mechanical polishing.
    Type: Grant
    Filed: May 10, 2012
    Date of Patent: March 17, 2015
    Assignee: SanDisk 3D LLC
    Inventors: Thomas H. Lee, Vivek Subramanian, James M. Cleeves, Mark G. Johnson, Paul Michael Farmwald, Igor G. Kouznetzov