Patents Assigned to SanDisk Technologies Inc.
  • Publication number: 20160172045
    Abstract: A non-volatile memory system mitigates the effects of open block reading by analyzing the un-programmed region of a block before programming to determine a potential for read disturbance. The system may determine a read count value associated with open block reading of the memory block and/or perform partial block erase verification. To mitigate the effects of open block read disturbance, the system performs partial block erase for the un-programmed region of the memory block and/or limits programming in the un-programmed region.
    Type: Application
    Filed: July 8, 2015
    Publication date: June 16, 2016
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: Pitamber Shukla, Henry Chin, Dana Lee, Cynthia Hsu
  • Publication number: 20160172368
    Abstract: A memory device and corresponding fabrication method prevent undesired diffusion of dopants from a silicon cap of a vertical NAND string to a channel film of the NAND string. Initially, a memory hole is provided in a stack of alternating control gate layers and dielectric layers. The memory hole is filled with annular films and a dielectric core filler. The dielectric core filler is etched back from a top of the memory hole to a topmost control gate layer, forming a void. A dopant stopper liner is deposited in the void before depositing n+ doped silicon which forms the silicon cap. The dopant stopper liner can be a conductive material such as metal or polysilicon doped with carbon. A conductive via is then formed above, and aligned with, the top of the silicon cap. A bit line may be formed over the conductive via.
    Type: Application
    Filed: December 16, 2014
    Publication date: June 16, 2016
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: Liang Pang, Jayavel Pachamuthu, Yingda Dong
  • Patent number: 9368510
    Abstract: A non-volatile storage device with memory cells having a high-k charge storage region, as well as methods of fabrication, is disclosed. The charge storage region has three or more layers of dielectric materials. At least one layer is a high-k material. The high-k layer(s) has a higher trap density as compared to Si3N4. High-k dielectrics in the charge storage region enhance capacitive coupling with the memory cell channel, which can improve memory cell current, program speed, and erase speed. The charge storage region has a high-low-high conduction band offset, which may improve data retention. The charge storage region has a low-high-low valence band offset, which may improve erase.
    Type: Grant
    Filed: May 26, 2015
    Date of Patent: June 14, 2016
    Assignee: SanDisk Technologies Inc.
    Inventors: Peter Rabkin, Jayavel Pachamuthu, Johann Alsmeier, Masaaki Higashitani
  • Patent number: 9368224
    Abstract: To maintain stability of memory array operations, a supplemental current can supply a common source line of a memory array so that the combined current from the memory array and supplemental current is at least a minimum regulation current level. When enabled for sensing operations, a driver circuit maintains the common source line's voltage level. A current subtractor circuit determines the difference between a reference current and a current proportional to the current flowing from the array, where the reference current is proportional to the minimum regulation current. The difference current is then mirrored by a self-adjusting current loop and supplied to the common source line to maintain its current level.
    Type: Grant
    Filed: February 7, 2014
    Date of Patent: June 14, 2016
    Assignee: SanDisk Technologies, Inc.
    Inventors: Sung-En Wang, Jonathan Huynh, Steve Choi, Jongmin Park
  • Patent number: 9368601
    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: Grant
    Filed: February 28, 2014
    Date of Patent: June 14, 2016
    Assignee: SanDisk Technologies Inc.
    Inventors: Michiaki Sano, Kensuke Yamaguchi, Akira Nakada, Naohito Yanagida
  • Patent number: 9367246
    Abstract: A single command initiates a first read operation and sequence of one or more additional read operations from the same portion of memory. The one or more additional read operations are terminable after the first read operation provides a first plurality of data values that is made available to a requesting device and/or module. In some implementations, the first plurality of data values includes hard information values. Subsequent pluralities of data values are generated from the same portion of memory until a terminating event occurs. In some implementations, until a terminating event occurs, a respective hybrid plurality of data values is generated by combining the latest read plurality of data values with one of a previously generated hybrid plurality of data values and the first plurality of data values. Each hybrid plurality of data values is representative of a corresponding plurality of soft information values.
    Type: Grant
    Filed: August 9, 2013
    Date of Patent: June 14, 2016
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Jack Edward Frayer, Aaron K. Olbrich
  • Patent number: 9368207
    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: January 7, 2015
    Date of Patent: June 14, 2016
    Assignee: SanDisk Technologies Inc.
    Inventors: Abhijit Bandyopadhyay, Roy E Scheuerlein, Chandrasekhar R Gorla, Brian Le
  • Patent number: 9368222
    Abstract: Disclosed herein are techniques for pre-charging channels when programming memory cells. A pre-charge voltage is applied to both selected bit lines and inhibited bit lines during a channel pre-charge phase. The pre-charge voltage is passed to the channels of NAND strings. The voltage on the inhibited bit lines is then reduced to a program inhibit voltage. Also, the voltage on the selected bit lines is reduced to a program enable voltage. Further, the pre-charge voltage from the channels of the selected NAND strings is discharged while maintaining the pre-charge voltage in the channels of the inhibited NAND strings. The potential in the channels of the inhibited NAND strings may then be boosted and a programming voltage may be applied to a selected word line.
    Type: Grant
    Filed: October 1, 2014
    Date of Patent: June 14, 2016
    Assignee: SanDisk Technologies Inc.
    Inventors: Mohan Vamsi Dunga, Masaaki Higashitani
  • Patent number: 9368509
    Abstract: A memory stack structure can be formed through a stack of an alternating plurality of first material layers and second material layers and through an overlying temporary material layer having a different composition than the first and second material layers. The memory stack structure can include a memory film and a semiconductor channel layer. The overlying temporary material layer is removed selective to the stack to form a lateral recess. Portions of the memory film are removed around the lateral recess, and dopants are laterally introduced into an upper portion of the semiconductor channel to form a self-aligned drain region.
    Type: Grant
    Filed: October 15, 2014
    Date of Patent: June 14, 2016
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Liang Pang, Jayavel Pachamuthu, Yingda Dong
  • Patent number: 9367353
    Abstract: A storage control system, and a method of operation thereof, including: a host interface module for receiving a host command from a host system; a power measurement module, coupled to the host interface module, for reading a current value of an electrical power supplied by the host system in response to the host command; and a schedule module, coupled to the power measurement module, for scheduling new operations to be executed in parallel in non-volatile memory devices, the new operations are scheduled when the current value of the electrical power does not exceed a power limit.
    Type: Grant
    Filed: June 25, 2013
    Date of Patent: June 14, 2016
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Robert W. Ellis, Kenneth B. DelPapa, Gregg S. Lucas, Ryan Jones
  • Publication number: 20160162357
    Abstract: Devices and methods implemented therein in are disclosed for correcting errors in data. The method comprises determining that a first copy of data and a second copy of data include errors uncorrectable by an error correction code (ECC) engine. The ECC engine is modified based on determining that the first copy of data and the second copy of data include errors uncorrectable by the ECC engine and using the modified ECC engine, the first copy of data and the second copy of data are processed to correct the errors in the first and second copy of the data.
    Type: Application
    Filed: March 13, 2015
    Publication date: June 9, 2016
    Applicant: SanDisk Technologies Inc.
    Inventors: Sateesh Desireddi, Nagi Reddy Chodem, Sachin Krishne Gowda
  • Publication number: 20160162219
    Abstract: A memory system and method are provided for selecting memory dies for memory access operations based on memory die temperatures. The memory system has a plurality of memory dies, where each memory die has its own temperature sensor. In one embodiment, the memory system selects which memory dies to perform memory access operations in based on the temperatures of the memory dies. In another embodiment, a controller of the memory system selects which memory dies to thermal throttle memory access operations in based on the detected temperatures. In yet another embodiment, a temperature-aware media management layer module of the memory l system routes a memory access operation from a first memory die to a second memory die based on the temperatures of the memory dies.
    Type: Application
    Filed: December 9, 2014
    Publication date: June 9, 2016
    Applicant: SanDisk Technologies Inc.
    Inventor: Eran Erez
  • Publication number: 20160163382
    Abstract: A non-volatile memory system including multi-level storage optimized for ramp sensing and soft decoding is provided. Sensing is performed at a higher bit resolution than an original user data encoding to improve the accuracy of reading state information from non-volatile storage elements. Higher resolution state information is used for decoding the original user data to improve read performance through improved error handling. Ramp sensing is utilized to determine state information by applying a continuous input scanning sense voltage that spans a range of read compare points. Full sequence programming is enabled as is interleaved coding of the user data over all of the data bit sets associated with the storage elements.
    Type: Application
    Filed: December 8, 2014
    Publication date: June 9, 2016
    Applicant: SanDisk Technologies Inc.
    Inventors: Kevin Michael Conley, Raul-Adrian Cernea, Eran Sharon, Idan Alrod
  • Publication number: 20160163393
    Abstract: Systems and methods for performing partial block erase operations on a subset of word lines within a memory array prior to performing data refreshing or open-block programming are described. In some cases, data stored in memory cells connected to a word line with a fail bit count above an error threshold (e.g., more than two bit errors per page or more than three bit errors per word line) may be refreshed by performing a read operation on the memory cells, generating corrected data for the memory cells, performing a partial block erase operation on one or more word lines including the word line, and then writing the corrected data into the memory cells. The one or more word lines may include the word line with the fail bit count above the error threshold and an adjacent word line that is adjacent to the word line.
    Type: Application
    Filed: September 24, 2015
    Publication date: June 9, 2016
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: Guirong Liang, Zhenming Zhou, Masaaki Higashitani
  • Publication number: 20160163397
    Abstract: A memory system or flash card may monitor the health of memory and the user data stored by detecting and storing a number of bits in error for each block. This detection can be used to determine where user data should be programmed and which blocks should be cycled. The erratic bits are detected after a programming and the listing for each block is updated. When the erratic bits exceed a threshold for a particular block, that block may be cycled or retired.
    Type: Application
    Filed: December 4, 2014
    Publication date: June 9, 2016
    Applicant: SanDisk Technologies Inc.
    Inventors: Rohit Sehgal, Nian Niles Yang
  • Patent number: 9361993
    Abstract: Read disturb is reduced in a charge-trapping memory device such as a 3D memory device by optimizing the channel boosting voltage in an unselected NAND string. A pass voltage applied to the unselected word lines can cause a large gradient in the channel which leads to electron-hole formation and a hot electron injection (HEI) type of read disturb. When the selected word line is close to the source-side of the NAND string, HEI disturb occurs on the drain-side of the selected word line. To avoid this disturb, a spike is provided in the control gate voltage of a drain-side selected gate transistor to temporarily connect the channel to the bit line, lowering the voltage of the associated channel region. A similar approach is used for a drain-side selected word line. The spike may be omitted when the selected word line is mid-range.
    Type: Grant
    Filed: January 21, 2015
    Date of Patent: June 7, 2016
    Assignee: SanDisk Technologies Inc.
    Inventors: Hong-Yan Chen, Yingda Dong, Wei Zhao, Charles Kwong
  • Patent number: 9361976
    Abstract: Methods are provided for use with a memory array that includes a selected memory cell coupled to a selected word line and a selected bit line, with the selected word line biased at a read voltage. The method include coupling a sense amplifier to the selected bit line, the sense amplifier including a capacitor integrator, a single-transistor amplifier and a level shifter, maintaining the selected bit line at a voltage of substantially 0V using the single-transistor amplifier and the level shifter, and integrating a selected bit line current on the capacitor integrator.
    Type: Grant
    Filed: November 12, 2014
    Date of Patent: June 7, 2016
    Assignee: SanDisk Technologies Inc.
    Inventors: Chang Siau, Yingchang Chen
  • Patent number: 9361030
    Abstract: A memory system or flash card may be exposed to elapsed time or increased temperature conditions which may degrade the memory. For example, extended time periods or high temperature conditions may hinder data retention in a memory device. An estimate of elapsed time and temperature conditions may be useful for memory management. An algorithm that periodically identifies one or more sentinel blocks in the memory device and measures the data retention shift in those sentinel blocks can calculate a scalar value that approximates the combined effect of elapsed time and/or temperature conditions.
    Type: Grant
    Filed: October 9, 2014
    Date of Patent: June 7, 2016
    Assignee: SanDisk Technologies Inc.
    Inventors: Daniel E. Tuers, Dana Lee, Henry Chin, Abhijeet Manohar
  • Patent number: 9361029
    Abstract: One method for improving the utility of solid-state storage media within a solid state storage device includes referencing one or more storage media characteristics for a set of storage cells of the solid-state storage media. The method also includes determining a configuration parameter for the set of storage cells based on the one or more storage media characteristics. The method includes configuring the set of storage cells to use the determined configuration parameter. The configuration parameter includes a parameter of the set of storage cells modifiable by a module external to the solid-state storage device by way of an interface. The module external to the solid-state storage device includes a device driver executing on a host device.
    Type: Grant
    Filed: January 30, 2015
    Date of Patent: June 7, 2016
    Assignee: SANDISK TECHNOLOGIES, INC.
    Inventors: John Strasser, David Flynn, Jeremy Fillingim, Robert Wood, Jea Hyun, Hairong Sun
  • Patent number: 9362338
    Abstract: Three-dimensional (3D) non-volatile memory arrays having a vertically-oriented thin film transistor (TFT) select device and method of fabricating 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 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 base thickness is defined by the deposition thickness, rather than an uncontrolled etch back.
    Type: Grant
    Filed: March 3, 2014
    Date of Patent: June 7, 2016
    Assignee: SanDisk Technologies Inc.
    Inventors: Naoki Takeguchi, Hiroaki Iuchi