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:
August 20, 2013
Date of Patent:
April 22, 2014
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
Abstract: A nonvolatile resistive memory element has a novel variable resistance layer that is passivated with non-metallic dopant atoms, such as nitrogen, either during or after deposition of the switching layer. The presence of the non-metallic dopant atoms in the variable resistance layer enables the switching layer to operate with reduced switching current while maintaining improved data retention properties.
Abstract: Embodiments of the invention generally include a method of forming a nonvolatile memory device that contains a resistive switching memory element that has improved device switching performance and lifetime, due to the addition of a current limiting component disposed therein. The electrical properties of the current limiting component are configured to lower the current flow through the variable resistance layer during the logic state programming steps by adding a fixed series resistance in the resistive switching memory element of the nonvolatile memory device. In one embodiment, the current limiting component comprises a tunnel oxide that is a current limiting material disposed within a resistive switching memory element in a nonvolatile resistive switching memory device.
Type:
Grant
Filed:
January 19, 2012
Date of Patent:
April 15, 2014
Assignees:
Sandisk 3D LLC, Kabushiki Kaisha Toshiba
Inventors:
Mihir Tendulkar, Imran Hashim, Yun Wang
Abstract: A non-volatile storage system is disclosed that includes a plurality of blocks of non-volatile storage elements, a plurality of word lines connected to the blocks of non-volatile storage elements such that each word line is connected to adjacent blocks of non-volatile storage elements, a plurality of bit lines connected to the blocks of non-volatile storage elements, multiple sets of word lines drivers such that each set of word line drivers is positioned between two adjacent blocks for driving word lines connected to the two adjacent blocks, global data lines, local data lines in selective communication with the bit lines, one or more selection circuits that selectively connect the global data lines to selected local data lines and connect unselected local data lines to one or more unselected bit line signals and control circuitry in communication with the one or more selection circuits and the global data lines.
Type:
Grant
Filed:
April 27, 2011
Date of Patent:
April 15, 2014
Assignee:
Sandisk 3D LLC
Inventors:
Tianhong Yan, Tz-yi Liu, Roy E. Scheuerlein
Abstract: A reversible resistance-switching metal-insulator-metal (MIM) stack is provided which can be set to a low resistance state with a first polarity signal and reset to a higher resistance state with a second polarity signal. The first polarity signal is opposite in polarity than the second polarity signal. In one approach, the MIM stack includes a carbon-based reversible resistivity switching material such as a carbon nanotube material. The MIM stack can further include one or more additional reversible resistivity switching materials such as metal oxide above and/or below the carbon-based reversible resistivity switching material. In another approach, a metal oxide layer is between separate layers of carbon-based reversible resistivity switching material.
Type:
Grant
Filed:
March 2, 2012
Date of Patent:
April 15, 2014
Assignee:
SanDisk 3D LLC
Inventors:
Jingyan Zhang, Utthaman Thirunavukkarasu, April D Schricker
Abstract: A re-writable resistance-switching memory cell includes first and second capacitors in series. The first and second capacitors may have balanced electrical characteristics to allow nearly concurrent, same-direction switching. The first capacitor has a first bipolar resistance switching layer between first and second conductive layers, and the second capacitor has a second bipolar resistance switching layer between third and fourth conductive layers. The first and third conductive layers are made of a common material, and the second and fourth conductive layers are made of a common material. In one approach, the first and second bipolar resistance switching layers are made of a common material and have common thickness. In another approach, the first and second bipolar resistance switching layers are made of materials having different dielectric constants, but their thickness differs in proportion to the difference in the dielectric constants, to provide a common capacitance per unit area.
Type:
Grant
Filed:
January 31, 2012
Date of Patent:
April 8, 2014
Assignee:
SanDisk 3D LLC
Inventors:
Roy E Scheuerlein, Henry Chien, Zhida Lan, Yung-Tin Chen
Abstract: Methods for preventing line collapse during the fabrication of NAND flash memory and other microelectronic devices that utilize closely spaced device structures with high aspect ratios are described. In some embodiments, one or more mechanical support structures may be provided to prevent the collapse of closely spaced device structures during fabrication. In one example, during fabrication of a NAND flash memory, one or more mechanical support structures may be set in place prior to performing a high aspect ratio word line etch for forming the NAND strings. The one or more mechanical support structures may comprise one or more fin supports that are arranged in a bit line direction. In another example, the one or more mechanical support structures may be developed during the word line etch for forming the NAND strings.
Abstract: Embodiments of the invention include a method of forming a nonvolatile memory device that contains a resistive switching memory element that has improved device switching performance and lifetime, due to the addition of a current limiting component disposed therein. The electrical properties of the current limiting component are configured to lower the current flow through the variable resistance layer during the logic state programming steps by adding a fixed series resistance in the resistive switching memory element of the nonvolatile memory device. In some embodiments, the current limiting component comprises a varistor that is a current limiting material disposed within a resistive switching memory element in a nonvolatile resistive switching memory device.
Type:
Grant
Filed:
February 17, 2012
Date of Patent:
April 1, 2014
Assignees:
SanDisk 3D LLC, Kabushiki Kaisha Toshiba
Inventors:
Mihir Tendulkar, Imran Hashim, Yun Wang
Abstract: A memory device in a 3-D read and write memory includes a resistance-changing layer, and a local contact resistance in series with, and local to, the resistance-changing layer. The local contact resistance is established by a junction between a semiconductor layer and a metal layer. Further, the local contact resistance has a specified level of resistance according to a doping concentration of the semiconductor and a barrier height of the junction. A method for fabricating such a memory device is also presented.
Abstract: A method is provided for programming a memory cell in a memory array. The memory cell includes a resistivity-switching layer of a metal oxide or nitride compound, and the metal oxide or nitride compound includes exactly one metal. The method includes programming the memory cell by changing the resistivity-switching layer from a first resistivity state to a second programmed resistivity state, wherein the second programmed resistivity state stores a data state of the memory cell. Numerous other aspects are provided.
Type:
Grant
Filed:
January 4, 2013
Date of Patent:
April 1, 2014
Assignee:
SanDisk 3D LLC
Inventors:
Scott Brad Herner, Christopher J. Petti, Tanmay Kumar
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: (a) includes a material from the family consisting of XvOw, wherein X represents an element from the family consisting of Hf and Zr, and wherein the subscripts v and w have non-zero values that form a stable compound, and (b) has a thickness between 20 and 65 angstroms. Other aspects are also provided.
Type:
Grant
Filed:
January 4, 2013
Date of Patent:
April 1, 2014
Assignee:
SanDisk 3D LLC
Inventors:
Xiaoyu Yang, Roy E. Scheuerlein, Feng Li, Albert T. Meeks
Abstract: Embodiments of the present invention generally relate to a resistive switching nonvolatile memory element that is formed in a resistive switching memory device that may be used in a memory array to store digital data. The memory element is generally constructed as a metal-insulator-metal stack. The resistive switching portion of the memory element includes a getter and/or a defect portion. In general, the getter portion is an area of the memory element that is used to help form, during the resistive switching memory device's fabrication process, a region of the resistive switching layer that has a greater number of vacancies or defects compared to the remainder of resistive switching layer. The defect portion is an area of the memory element that has a greater number of vacancies or defects compared to the remainder of the resistive switching layer, and is formed during the resistive switching memory device's fabrication process.
Type:
Application
Filed:
November 8, 2013
Publication date:
March 27, 2014
Applicants:
Kabushiki Kaisha Toshiba, SanDisk 3D LLC
Abstract: Methods of forming a microelectronic structure are provided, the microelectronic structure including a first conductor, a discontinuous film of metal nanoparticles disposed on a surface above the first conductor, a carbon nano-film formed atop the surface and the discontinuous film of metal nanoparticles, and a second conductor disposed above the carbon nano-film. Numerous additional aspects are provided.
Abstract: The present invention provides apparatus, methods, and systems for fabricating memory lines and structures using double sidewall patterning for four times half pitch relief patterning. The invention includes forming features from a first template layer disposed above a substrate, forming half-pitch sidewall spacers adjacent the features, forming smaller features in a second template layer by using the half-pitch sidewall spacers as a hardmask, forming quarter-pitch sidewall spacers adjacent the smaller features, and forming conductor features from a conductor layer by using the quarter-pitch sidewall spacers as a hardmask. Numerous additional aspects are disclosed.
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.
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:
January 18, 2012
Date of Patent:
March 25, 2014
Assignees:
Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLC
Abstract: A three-dimensional array adapted for memory elements that reversibly change a level of electrical conductance in response to a voltage difference being applied across them. Memory elements are formed across a plurality of planes positioned different distances above a semiconductor substrate. Bit lines to which the memory elements of all planes are connected are oriented vertically from the substrate and through the plurality of planes.
Abstract: A three-dimensional array adapted for memory elements that reversibly change a level of electrical conductance in response to a voltage difference being applied across them. Memory elements are formed across a plurality of planes positioned different distances above a semiconductor substrate. Bit lines to which the memory elements of all planes are connected are oriented vertically from the substrate and through the plurality of planes.
Abstract: Embodiments of the invention generally relate to a resistive switching nonvolatile memory device having an interface layer structure disposed between at least one of the electrodes and a variable resistance layer formed in the nonvolatile memory device, and a method of forming the same. Typically, resistive switching memory elements may be formed as part of a high-capacity nonvolatile memory integrated circuit, which can be used in various electronic devices, such as digital cameras, mobile telephones, handheld computers, and music players. In one configuration of the resistive switching nonvolatile memory device, the interface layer structure comprises a passivation region, an interface coupling region, and/or a variable resistance layer interface region that are configured to adjust the nonvolatile memory device's performance, such as lowering the formed device's switching currents and reducing the device's forming voltage, and reducing the performance variation from one formed device to another.
Type:
Application
Filed:
November 13, 2013
Publication date:
March 6, 2014
Applicants:
Intermolecular Inc., SanDisk 3D LLC, Kabushiki Kaisha Toshiba
Abstract: A three-dimensional (3D) high density memory array includes multiple layers of segmented bit lines (i.e., sense lines) with segment switch devices within the memory array that connect the segments to global bit lines. The segment switch devices reside on one or more layers of the integrated circuit, preferably residing on each bit line layer. The global bit lines reside preferably on one layer below the memory array, but may reside on more than one layer. The bit line segments preferably share vertical connections to an associated global bit line. In certain EEPROM embodiments, the array includes multiple layers of segmented bit lines with segment connection switches on multiple layers and shared vertical connections to a global bit line layer. Such memory arrays may be realized with much less write-disturb effects for half selected memory cells, and may be realized with a much smaller block of cells to be erased.
Type:
Grant
Filed:
June 18, 2007
Date of Patent:
February 25, 2014
Assignee:
SanDisk 3D LLC
Inventors:
Roy E. Scheuerlein, Alper Ilkbahar, Luca G. Fasoli