Patents Assigned to Sandisk 3D LLC
-
Patent number: 9196373Abstract: 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: GrantFiled: February 26, 2014Date of Patent: November 24, 2015Assignee: SANDISK 3D LLCInventors: Anurag Nigam, Gopinath Balakrishnan
-
Patent number: 9196362Abstract: Methods for forming non-volatile storage elements in a non-volatile storage system are described. In some embodiments, during a forming operation, a cross-point memory array may be biased such that waste currents are minimized or eliminated. In one example, the memory array may be biased such that a first word line comb is set to a first voltage, a second word line comb interdigitated with the first word line comb is set to the first voltage, and selected vertical bit lines are set to a second voltage such that a forming voltage is applied across non-volatile storage elements to be formed. In some embodiments, a memory array may include a plurality of word line comb layers and a forming operation may be concurrently performed on non-volatile storage elements on all of the plurality of word line comb layers or a subset of the plurality of word line comb layers.Type: GrantFiled: April 5, 2014Date of Patent: November 24, 2015Assignee: SANDISK 3D LLCInventors: Chang Siau, Tianhong Yan
-
Publication number: 20150333105Abstract: 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: ApplicationFiled: July 23, 2015Publication date: November 19, 2015Applicant: SANDISK 3D LLCInventors: George Matamis, James K. Kai, Vinod R. Purayath, Yuan Zhang, Henry Chien
-
Patent number: 9190134Abstract: A three-dimensional array especially 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. A two-dimensional array of bit lines to which the memory elements of all planes are connected is oriented vertically from the substrate and through the plurality of planes. A single-sided word line architecture provides a word line exclusively for each row of memory elements instead of sharing one word line between two rows of memory elements thereby avoids linking the memory element across the array across the word lines. While the row of memory elements is also being accessed by a corresponding row of local bit lines, there is no extension of coupling between adjacent rows of local bit lines and therefore leakage currents beyond the word line.Type: GrantFiled: January 13, 2014Date of Patent: November 17, 2015Assignee: SANDISK 3D LLCInventor: George Samachisa
-
Publication number: 20150325292Abstract: 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.Type: ApplicationFiled: June 22, 2015Publication date: November 12, 2015Applicant: SANDISK 3D LLCInventor: Roy E. Scheuerlein
-
Publication number: 20150325310Abstract: A method of programming a memory cell is provided. The memory cell includes a memory element having a first conductive material layer, a first dielectric material layer above the first conductive material layer, a second conductive material layer above the first dielectric material layer, a second dielectric material layer above the second conductive material layer, and a third conductive material layer above the second dielectric material layer. One or both of the first and second conductive material layers comprises a stack of a metal material layer and a highly doped semiconductor material layer. The memory cell has a first memory state upon fabrication corresponding to a first read current. The method includes applying a first programming pulse to the memory cell with a first current limit. The first programming pulse programs the memory cell to a second memory state that corresponds to a second read current greater than the first read current.Type: ApplicationFiled: July 20, 2015Publication date: November 12, 2015Applicant: SANDISK 3D LLCInventors: Abhijit Bandyopadhyay, Tanmay Kumar, Scott Brad Herner, Christopher J. Petti, Roy E. Scheuerlein
-
Patent number: 9184379Abstract: A thin cap of metal alloy or metal-silicon compound is formed over a ternary oxide or ternary nitride ReRAM embedded resistor. At least one metal in the cap is the same as a metal in the embedded resistor. If the cap oxidizes slightly (e.g., incidental to a vacuum break, anneal, or subsequent treatment or deposition), the overall resistance of the memory cell is much less affected than it would be by the same amount of oxidation directly on a surface of the uncapped oxide or nitride embedded resistor.Type: GrantFiled: July 18, 2014Date of Patent: November 10, 2015Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLCInventor: Yun Wang
-
Patent number: 9184383Abstract: 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: GrantFiled: January 16, 2014Date of Patent: November 10, 2015Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLCInventors: Yun Wang, Tony P. Chiang, Imran Hashim
-
Patent number: 9178000Abstract: Provided are resistive random access memory (ReRAM) cells having extended conductive layers operable as electrodes of other devices, and methods of fabricating such cells and other devices. A conductive layer of a ReRAM cell extends beyond the cell boundary defined by the variable resistance layer. The extended portion may be used a source or drain region of a FET that may control an electrical current through the cell or other devices. The extended conductive layer may be also operable as electrode of another resistive-switching cell or a different device. The extended conductive layer may be formed from doped silicon. The variable resistance layer of the ReRAM cell may be positioned on the same level as a gate dielectric layer of the FET. The variable resistance layer and the gate dielectric layer may have the same thickness and share common materials, though they may be differently doped.Type: GrantFiled: April 29, 2014Date of Patent: November 3, 2015Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLCInventors: Federico Nardi, Ryan C. Clarke, Tim Minvielle, Yun Wang
-
Patent number: 9178148Abstract: 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: GrantFiled: March 3, 2015Date of Patent: November 3, 2015Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLCInventors: Imran Hashim, Ryan C. Clarke, Nan Lu, Tim Minvielle, Takeshi Yamaguchi
-
Patent number: 9178151Abstract: 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: GrantFiled: November 13, 2013Date of Patent: November 3, 2015Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLCInventors: Yun Wang, Tony P. Chiang, Imran Hashim
-
Patent number: 9177964Abstract: A method of forming sidewall gates for vertical transistors includes depositing a gate dielectric layer over polysilicon channel structures, and depositing a gate polysilicon layer over the gate dielectric. The gate polysilicon layer is then etched back to form separated gate electrodes. Filler portions are then formed between gate electrodes, which are then etched from the top down while their sides are protected.Type: GrantFiled: December 6, 2013Date of Patent: November 3, 2015Assignee: SanDisk 3D LLCInventors: Akira Nakada, Michiaki Sano, Naohito Yanagida, Teruyuki Mine
-
Patent number: 9178140Abstract: 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: GrantFiled: February 17, 2015Date of Patent: November 3, 2015Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLCInventors: Federico Nardi, Yun Wang
-
Publication number: 20150311257Abstract: Provided are resistive random access memory (ReRAM) cells having extended conductive layers operable as electrodes of other devices, and methods of fabricating such cells and other devices. A conductive layer of a ReRAM cell extends beyond the cell boundary defined by the variable resistance layer. The extended portion may be used a source or drain region of a FET that may control an electrical current through the cell or other devices. The extended conductive layer may be also operable as electrode of another resistive-switching cell or a different device. The extended conductive layer may be formed from doped silicon. The variable resistance layer of the ReRAM cell may be positioned on the same level as a gate dielectric layer of the FET. The variable resistance layer and the gate dielectric layer may have the same thickness and share common materials, though they may be differently doped.Type: ApplicationFiled: April 29, 2014Publication date: October 29, 2015Applicants: Intermolecular Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLCInventors: Federico Nardi, Ryan C. Clarke, Tim Minvielle, Yun Wang
-
Publication number: 20150311256Abstract: 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: ApplicationFiled: July 7, 2015Publication date: October 29, 2015Applicant: SANDISK 3D LLCInventors: Peter Rabkin, Masaaki Higashitani
-
Patent number: 9171857Abstract: 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: GrantFiled: September 23, 2014Date of Patent: October 27, 2015Assignee: SANDISK 3D LLCInventors: Thomas H. Lee, Vivek Subramanian, James M. Cleeves, Igor G. Kouznetsov, Mark G. Johnson, Paul Michael Farmwald
-
Patent number: 9171584Abstract: A three-dimensional array of memory elements reversibly change a level of electrical conductance/resistance in response to one or more voltage differences being applied across them. Memory elements are formed across a plurality of planes positioned different distances above a semiconductor substrate. Local bit lines to which the memory elements of all planes are connected are oriented vertically from the substrate and through the plurality of planes. Vertically oriented select devices are used to connect the local bit lines to global bit lines. A first subset of the vertically oriented select devices are positioned above the vertically oriented bit lines and a second subset of the vertically oriented select devices (interleaved with the first subset of the vertically oriented select devices) are positioned below the vertically oriented bit lines.Type: GrantFiled: May 3, 2013Date of Patent: October 27, 2015Assignee: SanDisk 3D LLCInventors: Roy E. Scheuerlein, Chang Siau
-
Patent number: 9165933Abstract: A 3D memory array having a vertically oriented thin film transistor (TFT) selection device that has a channel extension, otherwise referred to as a gate/junction offset, is disclosed. The vertically oriented TFT selection device with channel extension serves as a vertical bit line selection device in the 3D memory array. A vertical TFT select device having a channel extension has a high breakdown voltage and low leakage current. The channel extension can be at the top junction or bottom junction of the TFT. Depending on whether the memory elements undergo a forward FORM or reverse FORM, either the bottom or top junction can have the channel extension. This provides for a high voltage junction where needed.Type: GrantFiled: March 7, 2013Date of Patent: October 20, 2015Assignee: SanDisk 3D LLCInventors: Peter Rabkin, Masaaki Higashitani
-
Patent number: 9152562Abstract: Methods and apparatus for a solid state non-volatile storage sub-system of a computer is provided. The storage sub-system may include a write-many storage sub-system memory device including write-many memory cells, a write-once storage sub-system memory device including write-once memory cells, and a page-based interface that is adapted to read and write the write-once and write-many storage sub-system memory devices. Numerous other aspects are provided.Type: GrantFiled: September 14, 2012Date of Patent: October 6, 2015Assignee: SanDisk 3D LLCInventors: Roy E. Scheuerlein, Randhir Thakur, Christopher Moore
-
Publication number: 20150279850Abstract: An embodiment relates to a transistor device including a pillar of semiconductor material extending vertically from a bottom portion in contact with an electrically conductive contact line, where the electrically conductive contact line extends laterally past the pillar in a horizontal direction, a gate insulating liner layer on a lateral side of the pillar, a gate electrode on the gate insulating layer extending along the lateral side of the pillar, and a region of electrically insulating semiconductor oxide material filling a space between a bottom portion of the gate electrode and a top portion of the electrically conductive contact line.Type: ApplicationFiled: March 25, 2014Publication date: October 1, 2015Applicant: SanDisk 3D LLCInventor: Seje Takaki