Patents Assigned to Sandisk 3D LLC
  • Patent number: 9147439
    Abstract: In a 3D nonvolatile memory with memory elements arranged in a three-dimensional pattern defined by rectangular coordinates having x, y and z-directions and with a plurality of parallel planes from a bottom plane to a top plane stacked in the z-direction over a semiconductor substrate; a plurality of local bit lines elongated in the z-direction through the plurality of layers and arranged in a two-dimensional rectangular array of bit line pillars having rows in the x-direction and columns in the y-direction; the 3D nonvolatile memory further having a plurality of staircase word lines spaced apart in the y-direction and between and separated from the plurality of bit line pillars at a plurality of crossings, individual staircase word lines each having a series of alternating steps and risers elongated respectively in the x-direction and z-direction traversing across the plurality of planes in the z-direction with a segment in each plane.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: September 29, 2015
    Assignee: SANDISK 3D LLC
    Inventors: Raul Adrian Cernea, George Samachisa
  • Publication number: 20150263074
    Abstract: A device is disclosed including one or more field effect transistors, each field effect transistor including: an elongated drain contact line including an electrically conductive material extending along a first horizontal direction; a drain including a first conductivity type semiconductor region overlaying the drain contact line; a source including a the first conductivity type semiconductor region located above the drain; and a gate extending vertically between the drain and the source.
    Type: Application
    Filed: March 12, 2014
    Publication date: September 17, 2015
    Applicant: SanDisk 3D LLC
    Inventor: Seje Takaki
  • Publication number: 20150255619
    Abstract: Three-dimensional (3D) non-volatile memory arrays having a vertically-oriented thin film transistor (TFT) select device and method of fabricating such a memory are described. The vertically-oriented TFT may be used as a vertical bit line selection device to couple a global bit line to a vertical bit line. A select device pillar includes a body and upper and lower source/drain regions. At least one gate is separated horizontally from the select device pillar by a gate dielectric. Beneath each gate, a single gap fill dielectric layer extends vertically from a lower surface of the gate, at least partially separating the gate from the underlying global bit line. Between horizontally adjacent pillars, this same dielectric layer extends from its same lower level beneath the gates vertically to a level of the upper source/drain region.
    Type: Application
    Filed: March 5, 2014
    Publication date: September 10, 2015
    Applicant: SanDisk 3D LLC
    Inventor: Seiji Shimabukuro
  • Patent number: 9130165
    Abstract: Embodiments of the invention generally relate to nonvolatile memory devices, such as a ReRAM cells, and methods for manufacturing such memory devices, which includes optimized, atomic layer deposition (ALD) processes for forming metal oxide film stacks. The metal oxide film stacks contain a metal oxide coupling layer disposed on a metal oxide host layer, each layer having different grain structures/sizes. The interface disposed between the metal oxide layers facilitates oxygen vacancy movement. In many examples, the interface is a misaligned grain interface containing numerous grain boundaries extending parallel to the electrode interfaces, in contrast to the grains in the bulk film extending perpendicular to the electrode interfaces. As a result, oxygen vacancies are trapped and released during switching without significant loss of vacancies.
    Type: Grant
    Filed: October 3, 2014
    Date of Patent: September 8, 2015
    Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLC
    Inventors: Yun Wang, Tony P. Chiang, Vidyut Gopal, Imran Hashim, Dipankar Pramanik
  • Publication number: 20150249143
    Abstract: A fabrication process for a vertical channel transistor provides a desired control gate-to-drain overlap and sufficient isolation between the control gate and an underlying metal line. A body of the transistor is formed on a metal line, such as in a pillar shape. The metal line is oxidized to form metal oxide regions having an expanded volume. A gate insulator material and a control gate material are then deposited. The resulting structure is etched to form separate control gates for each transistor, and to expose the metal oxide. A further etch is performed to remove the metal oxide, forming voids under and around the control gates. An insulation fills the voids. An example implementation is a vertical bit line memory device in which the transistors connect a vertical bit line to a horizontal bit line.
    Type: Application
    Filed: February 28, 2014
    Publication date: September 3, 2015
    Applicant: SanDisk 3D LLC
    Inventors: Michiaki Sano, Kensuke Yamaguchi, Akira Nakada, Naohito Yanagida
  • Publication number: 20150249112
    Abstract: Three-dimensional (3D) non-volatile memory arrays having a vertically-oriented thin film transistor (TFT) select device and method of fabricating such a memory are described. The vertically-oriented TFT may be used as a vertical bit line selection device to couple a global bit line to a vertical bit line. A select device pillar includes a body and upper and lower source/drain regions. At least one gate is separated horizontally from the select device pillar by a gate dielectric. Each gate is formed over the gate dielectric and a base that extends horizontally at least partially between adjacent pillars. The base is formed with notches that are filled with the gate dielectric. The select device is fabricated using a conformally deposited base dielectric material and conformal hard mask layer that is formed with a larger bottom thickness than horizontal thickness. The hard mask permits the base thickness to be defined by the deposition thickness, rather than an uncontrolled etch back.
    Type: Application
    Filed: March 3, 2014
    Publication date: September 3, 2015
    Applicant: SanDisk 3D LLC
    Inventors: Naoki Takeguchi, Hiroaki Iuchi
  • Publication number: 20150248933
    Abstract: Methods for reducing power consumption of a non-volatile storage system and reducing first read latency are described. The non-volatile storage system may include a cross-point memory array. In some embodiments, during a standby mode, the memory array may be biased such that both word lines and bit lines are set to ground. During transition of the memory array from the standby mode to a read mode, a selected word line comb may be set to a read voltage while the unselected word lines and the bit lines remain at ground. During the read mode, memory cells connected to the selected bit lines and the selected word line comb may be sensed while the selected bit lines are biased to a selected bit line voltage equal to or close to ground and the unselected bit lines are left floating after initially being set to ground.
    Type: Application
    Filed: April 29, 2015
    Publication date: September 3, 2015
    Applicant: SANDISK 3D LLC
    Inventor: Chang Siau
  • Patent number: 9123890
    Abstract: A reversible resistance-switching memory cell has multiple narrow, spaced apart bottom electrode structures. The raised structures can be formed by coating a bottom electrode layer with nano-particles and etching the bottom electrode layer. The raised structures can be independent or joined to one another at a bottom of the bottom electrode layer. A resistance-switching material is provided between and above the bottom electrode structure, followed by a top electrode layer. Or, insulation is provided between and above the bottom electrode structures, and the resistance-switching material and top electrode layer are above the insulation. Less than one-third of a cross-sectional area of each resistance-switching memory cell is consumed by the one or more raised structures. When the resistance state of the memory cell is switched, there is a smaller area in the bottom electrode for a current path, so the switching resistance is higher and the switching current is lower.
    Type: Grant
    Filed: February 14, 2013
    Date of Patent: September 1, 2015
    Assignee: SanDisk 3D LLC
    Inventors: George Matamis, James K Kai, Vinod R Purayath, Yuan Zhang, Henry Chien
  • Patent number: 9123392
    Abstract: A three-dimensional array of memory elements is formed across multiple layers of planes positioned at different distances above a semiconductor substrate. The memory elements are each accessible by a word line in a plane and a local bit line. The three-dimensional array includes a two-dimensional array of pillar lines through the multiple layers of planes. The pillar lines are of a first type that act as local bit lines and a second type that provide access to the word lines by having respective memory elements preset to a permanently low resistance state for connecting second-type pillar lines for exclusive access to respective word lines. An array of metal lines on the substrate is switchably connected to the vertical bit lines to provide access to the local bit lines and the word lines.
    Type: Grant
    Filed: March 28, 2014
    Date of Patent: September 1, 2015
    Assignee: SANDISK 3D LLC
    Inventors: Tianhong Yan, Roy Edwin Scheuerlein
  • Patent number: 9123430
    Abstract: The selected bit line in a non-volatile memory carries a cell conduction current to be measured and also a leakage current or noise due to weak coupling with neighboring array structures. In a first phase, a sense amplifier senses the bit line current by discharging a capacitor with the combined current (cell conduction current plus the leakage current) over a predetermined time. In a second phase, the cell conduction current is minimized and significantly the leakage current in the selected bit line is used to recharge in tandem the capacitor in a time same as the predetermined time, effectively subtracting the component of the leakage current measured in the first sensing phase. The resultant voltage drop on the capacitor over the two sensing phases provides a measure of the cell conduction current alone, thereby avoiding reading errors due to the leakage current present in the selected bit line.
    Type: Grant
    Filed: June 14, 2013
    Date of Patent: September 1, 2015
    Assignee: SANDISK 3D LLC
    Inventor: Raul Adrian Cernea
  • Publication number: 20150243362
    Abstract: Methods for determining memory cell states during a read operation using a detection scheme that reduces the area of detection circuitry for detecting the states of the memory cells by time multiplexing the use of portions of the detection circuitry are described. The read operation may include a precharge phase, a sensing phase, and a detection phase. In some embodiments, a first bit line and a second bit line may be precharged to a read voltage in parallel, and then sensing and/or detection of selected memory cells corresponding with the first bit line and the second bit line may be performed serially using the same detection circuitry by time multiplexing the use of the detection circuitry. In some cases, the time multiplexed detection circuitry may be used for detecting two or more states corresponding with two or more memory cells being sensed during a read operation.
    Type: Application
    Filed: February 26, 2014
    Publication date: August 27, 2015
    Applicant: SANDISK 3D LLC
    Inventors: Anurag Nigam, Gopinath Balakrishnan
  • Patent number: 9111800
    Abstract: A plurality of integrated circuit features are provided in the context of an array of memory cells including a plurality of word lines and a plurality of bit lines. Each memory cell includes a floating body or is volatile memory. The aforementioned features may include, among others, an option whereby the foregoing bit lines may be situated below a channel region of corresponding memory cells, etc.
    Type: Grant
    Filed: September 22, 2010
    Date of Patent: August 18, 2015
    Assignee: SanDisk 3D LLC
    Inventor: Roy E. Scheuerlein
  • Patent number: 9105468
    Abstract: A 3D memory array having a vertically oriented thin film transistor (TFT) selection device that has a body formed from a wide energy band gap semiconductor is disclosed. The wide energy band gap semiconductor may be an oxide semiconductor, such as a metal oxide semiconductor. As examples, this could be an InGaZnO, InZnO, HfInZnO, or ZnInSnO body. The source and drains can also be formed from the wide energy band gap semiconductor, although these may be doped for better conduction. The vertically oriented TFT selection device serves as a vertical bit line selection device in the 3D memory array. A vertical TFT select device has a high drive current, a high breakdown voltage and low leakage current.
    Type: Grant
    Filed: September 6, 2013
    Date of Patent: August 11, 2015
    Assignee: SanDisk 3D LLC
    Inventors: Peter Rabkin, Masaaki Higashitani
  • Patent number: 9105576
    Abstract: In some embodiments, a memory array is provided that includes (1) a first memory cell having (a) a first conductive line; (b) a first bipolar storage element formed above the first conductive line; and (c) a second conductive line formed above the first bipolar storage element; and (2) a second memory cell formed above the first memory cell and having (a) a second bipolar storage element formed above the second conductive line; and (b) a third conductive line formed above the second bipolar storage element. The first and second memory cells share the second conductive line; the first bipolar storage element has a first storage element polarity orientation within the first memory cell; the second bipolar storage element has a second storage element polarity orientation within the second memory cell; and the second storage element polarity orientation is opposite the first storage element polarity orientation. Numerous other aspects are provided.
    Type: Grant
    Filed: August 11, 2014
    Date of Patent: August 11, 2015
    Assignee: SanDisk 3D LLC
    Inventors: Yung-Tin Chen, Andrei Mihnea, Roy E. Scheuerlein, Luca Fasoli
  • Patent number: 9099385
    Abstract: Vertical 1T-1R memory cells, memory arrays of vertical 1T-1R memory calls, and methods of forming such memory cells and memory arrays are described. The memory cells each include a vertical transistor and a resistivity-switching element coupled in series with and disposed above or below the vertical transistor. The vertical transistor includes a controlling electrode coupled to a word line that is above or below the vertical transistor. The controlling electrode is disposed on a sidewall of the vertical transistor. Each vertical transistor includes a first terminal coupled to a bit line, a second terminal comprising the controlling electrode coupled to a word line, and a third terminal coupled to the resistivity-switching element.
    Type: Grant
    Filed: November 8, 2013
    Date of Patent: August 4, 2015
    Assignee: SanDisk 3D LLC
    Inventor: Christopher J. Petti
  • Patent number: 9087978
    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: February 10, 2015
    Date of Patent: July 21, 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: 9082786
    Abstract: A method of forming a memory cell is provided. The method includes forming a first pillar-shaped element that includes a first semiconductor material, forming a first opening self-aligned with the first pillar-shaped element, and depositing a second semiconductor material in the first opening to form a second pillar-shaped element above the first pillar-shaped element. Other aspects are also provided.
    Type: Grant
    Filed: December 24, 2013
    Date of Patent: July 14, 2015
    Assignee: SANDISK 3D LLC
    Inventors: Kang-Jay Hsia, Calvin K. Li, Christopher John Petti
  • Publication number: 20150194380
    Abstract: A multilevel device includes: at least one device region and at least one contact region having a stack of alternating plurality of continuous electrically conductive layers and plurality of electrically insulating layers located over a base. Each electrically conductive layer in the stack is electrically insulated from the other electrically conductive layers in the stack. The base may include a raised portion and a plurality of recesses in the raised portion, each recess in the plurality of recesses having a different lateral size from the other recesses in the plurality of recesses. The electrically conductive layers in the stack may be substantially conformal to the plurality of recesses in the base and expose one or more top surfaces of the raised portion of the base. A first electrically conductive layer in the stack may be a topmost layer in a laterally central portion of a first one of the plurality of recesses.
    Type: Application
    Filed: January 8, 2014
    Publication date: July 9, 2015
    Applicant: SanDisk 3D LLC
    Inventors: Seje Takaki, Michiaki Sano, Zhen Chen
  • Patent number: 9076518
    Abstract: A three-dimensional non-volatile memory system is disclosed including a memory array utilizing shared pillar structures for memory cell formation. A shared pillar structure includes two non-volatile storage elements. A first end surface of each pillar contacts one array line from a first set of array lines and a second end surface of each pillar contacts two array lines from a second set of array lines that is vertically separated from the first set of array lines. Each pillar includes a first subset of layers that are divided into portions for the individual storage elements in the pillar. Each pillar includes a second subset of layers that is shared between both non-volatile storage elements formed in the pillar. The individual storage elements each include a steering element and a state change element.
    Type: Grant
    Filed: February 3, 2012
    Date of Patent: July 7, 2015
    Assignee: SanDisk 3D LLC
    Inventors: Roy E. Scheuerlein, Eliyahou Harari
  • Publication number: 20150179659
    Abstract: A multi-level device includes at least one device region and at least one contact region. The contact region has a stack of alternating plurality of electrically conductive layers and plurality of electrically insulating layers located over a substrate. The plurality of electrically conductive layers form a stepped pattern in the contact region, where each respective electrically insulating layer includes a sidewall and a respective underlying electrically conductive layer in the stack extends laterally beyond the sidewall.
    Type: Application
    Filed: December 20, 2013
    Publication date: June 25, 2015
    Applicant: SanDisk 3D LLC
    Inventor: Seje Takaki