Patents Assigned to SanDisk Technologies LLC
  • Patent number: 10770165
    Abstract: Techniques are described for programming memory cells without performing a verify test, where the programming is followed by a short circuit test. In one aspect, an initial programming is performed on memory cells of a first word line of a block using a program pulse with an initial magnitude, Vpgm. By reading the memory cells, Vpgm can be optimized for programming subsequent word lines. The subsequent word lines may be programmed using a no-verify program operation followed by a word line short circuit test, for one or more word lines involved in the program operation. The short circuit test can be performed concurrently on a single word line, multiple word lines and/or one or more sub-blocks of a block, based on an amount of write data which can be storage by a controller.
    Type: Grant
    Filed: September 16, 2019
    Date of Patent: September 8, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Xue Qing Cai, Jiahui Yuan, Deepanshu Dutta
  • Patent number: 10762973
    Abstract: Program disturb is suppressed during a program recovery phase of a program operation in a memory device. The duration of the recovery phase can be increased when the risk of program disturb is greater due to factors such as temperature, the position of the selected word line, the number of program-erase cycles and the program pulse magnitude. In other approaches, the risk of program disturb is reduced by providing an early ramp down of the voltages of the drain-side word line relative to a ramp down of the voltages of the source-side word lines, providing an early ramp down of the bit line voltage of the inhibited NAND strings relative to the ramp down of the select gate voltage or setting a lower recovery voltage for the source-side word lines relative to the recovery voltage of the drain-side word lines.
    Type: Grant
    Filed: May 10, 2019
    Date of Patent: September 1, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Ching-Huang Lu, Zhengyi Zhang
  • Patent number: 10755788
    Abstract: An apparatus comprising an impedance compensation circuit is disclosed. The impedance compensation circuit compensates for impedance differences between a first pathway connected to a first transistor and a second pathway connected to a second transistor. However, rather than making a compensation based on a signal (e.g., voltage) applied to either the first or the second pathway, a compensation is made based on the signals (e.g., voltage pulses) applied to third and fourth pathways connected to the transistors.
    Type: Grant
    Filed: December 27, 2018
    Date of Patent: August 25, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Peter Rabkin, Kwang-Ho Kim, Masaaki Higashitani, Yingda Dong
  • Publication number: 20200265880
    Abstract: A memory device and associated techniques improve a settling time of bit lines in a memory device during a read or verify operation. Bit line control (BLC) transistors in the sense circuits are briefly turned off during a sensing process. After the read voltage on a selected word line is changed to a second word line level or higher, a control gate voltage of the BLC transistor is lowered, helping to inhibit a current flow from a sense circuit through a bit line when a voltage of the bit line is settling. The voltage of the bit line may be settling in response to a memory cell coupled to the selected word line undergoing a transition from off to on. A settling time of the bit line is shortened by stopping the current flow from the sense circuit. Transition of the memory cell from off to on is also improved.
    Type: Application
    Filed: May 4, 2020
    Publication date: August 20, 2020
    Applicant: SanDisk Technologies LLC
    Inventor: Hiroki Yabe
  • Publication number: 20200265899
    Abstract: A memory device and associated techniques improve a settling time of bit lines in a memory device during a sensing operation, such as read or verify operation. Supply voltage from power supply terminals in the sense circuits is briefly toggled during a discharge of a selected bit line in response to a voltage on a selected word line being increased to a second word line level or higher. This helps to create an electrical path from the selected bit line through to a supply terminal for discharging the selected bit line such that a settling time of a voltage of the selected bit line is shortened in association with a target memory cell transitioning from a non-conductive state to a conductive state.
    Type: Application
    Filed: May 4, 2020
    Publication date: August 20, 2020
    Applicant: SanDisk Technologies LLC
    Inventors: Kenneth Louie, Anirudh Amarnath
  • Publication number: 20200265897
    Abstract: Techniques are provided for optimizing an erase operation in a memory device to compensate for erase speed variations due to blocking oxide thinning In an erase operation for a block, the channels of NAND strings in different sub-blocks can be charged up by different amounts. One approach adjusts the control gate voltage of a first select gate transistor in a NAND string. This adjusts the amount of holes generated in the channel due to gate-induced drain leakage. Another approach adjusts the control gate voltage of additional select gate transistors in the NAND string to adjust the conductivity of the adjacent channel regions. Another approach applies different bit line voltages to different rows of NAND strings in each sub-block.
    Type: Application
    Filed: February 20, 2019
    Publication date: August 20, 2020
    Applicant: SanDisk Technologies LLC
    Inventors: Ching-Huang Lu, Ashish Baraskar, Vinh Diep
  • Patent number: 10747676
    Abstract: Systems, methods and/or devices are used to perform memory-efficient mapping of block/object addresses. In one aspect, a method of managing a storage system having one or more storage devices includes a tiered data structure in which each node has a logical ID and entries in the nodes reference other nodes in the tiered data structure using the logical IDs. As a result, when a child node is updated and stored to a new location, but retains its logical ID, its parent node does not need to be updated, because the logical ID in the entry referencing the child node remains unchanged. Further, the storage system uses a secondary mapping table to translate the logical IDs to the corresponding physical locations of the corresponding nodes. Additionally, the secondary mapping table is cached in volatile memory, and as a result, the physical location of a required node is determined without accessing non-volatile memory.
    Type: Grant
    Filed: July 12, 2016
    Date of Patent: August 18, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Brian W. O'Krafka, Frederic H. Tudor, Niranjan Patre Neelakanta, Manavalan Krishnan, Johann George, Evgeniy Firsov
  • Patent number: 10748622
    Abstract: Techniques are provided for predictively programming of non-volatile memory, which may reduce the number of verify operations. In one aspect, a programming circuit is configured to program memory cells to a verify low voltage and to program a set of the memory cells to target states. The set comprises memory cells having a threshold voltage between the verify low voltage and a verify high voltage. To program the set of the memory cells to the target states, the programming circuit is configured to apply two or more program pulses to memory cells in the set without verifying whether the memory cells have reached their respective target states, including: apply a first and second program enable voltages to the bit lines associated with the memory cells having different strengths.
    Type: Grant
    Filed: February 22, 2019
    Date of Patent: August 18, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Lei Lin, Zhuojie Li, Tai-Yuan Tseng, Henry Chin, Gerrit Jan Hemink
  • Patent number: 10748619
    Abstract: Techniques are described for configuring a memory device with parameters for multiple operating modes including M-bit per cell and N-bit per cell operating modes. The parameters can be stored in ROM storage locations of the memory device and loaded into registers when powering on the memory device. The parameters can be accessed by a state machine based on command sequences receive from a controller. The command sequences can include one or more prefix commands which specify the operating mode, e.g., the number of bits per cell, commands which specify a type of an operation, and an address of memory cells on which the operation is to be performed. The state machine can easily switch between accessing parameters for different modes without the controller including the parameters in the command sequences.
    Type: Grant
    Filed: May 8, 2019
    Date of Patent: August 18, 2020
    Assignee: SanDisk Technologies LLC
    Inventor: Liang Li
  • Patent number: 10748627
    Abstract: Techniques for reducing neighbor word line interference (NWI) of memory cells which are formed in a two-tier stack having a lower tier and an upper tier separated by an interface. In one approach, an upward word line programming order is used for a top portion of the top tier, and a downward word line programming order is used for a bottom portion of the top tier and for the bottom tier. Additionally, for memory cells which receive NWI from both adjacent word lines, options include programming fewer bits per cell, performing multi-pass programming and/or use lower verify voltages. Options also include increasing a control gate length of the memory cells and increasing a height of a dielectric region adjacent to the memory cells.
    Type: Grant
    Filed: December 21, 2018
    Date of Patent: August 18, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Hong-Yan Chen, Yingda Dong, Zhengyi Zhang
  • Publication number: 20200258571
    Abstract: Apparatuses, systems, and methods are disclosed for adjusting a programming setting such as a programming voltage of a set of non-volatile storage cells, such as an SLC NAND array. The non-volatile storage cells may be arranged into a plurality of word lines. A subset of the non-volatile storage cells may be configured to store a programming setting. An on-die controller may be configured to read the programming setting from the setting subset, and write data to the non-volatile storage cells, using the programming setting. The on-die controller may further be configured to determine that the programming setting causes suboptimal programming of one or more of the non-volatile storage cells, and in response to the determination, store a revised programming setting on the setting subset.
    Type: Application
    Filed: March 25, 2020
    Publication date: August 13, 2020
    Applicant: SanDisk Technologies LLC
    Inventors: Xiang Yang, Huai-Yuan Tseng, Deepanshu Dutta
  • Patent number: 10740228
    Abstract: Systems, methods and/or devices are used to enable locality grouping during garbage collection of a storage device. In one aspect, the method includes, at a storage controller for the storage device: performing one or more operations for a garbage collection read, including: identifying one or more sequences of valid data in a source unit, wherein each identified sequence of valid data has a length selected from a set of predefined lengths; and for each respective sequence of the one or more sequences of valid data in the source unit, transferring the respective sequence to a respective queue of a plurality of queues, in accordance with the length of the respective sequence; and performing one or more operations for a garbage collection write, including: identifying full respective queues for writing to a destination unit; and writing from the full respective queues to the destination unit.
    Type: Grant
    Filed: May 17, 2018
    Date of Patent: August 11, 2020
    Assignee: Sandisk Technologies LLC
    Inventors: Neil D. Hutchison, Steven Theodore Sprouse, Shakeel I. Bukhari
  • Patent number: 10741253
    Abstract: Techniques are provided for optimizing an erase operation in a memory device to compensate for erase speed variations due to blocking oxide thinning In an erase operation for a block, the channels of NAND strings in different sub-blocks can be charged up by different amounts. One approach adjusts the control gate voltage of a first select gate transistor in a NAND string. This adjusts the amount of holes generated in the channel due to gate-induced drain leakage. Another approach adjusts the control gate voltage of additional select gate transistors in the NAND string to adjust the conductivity of the adjacent channel regions. Another approach applies different bit line voltages to different rows of NAND strings in each sub-block.
    Type: Grant
    Filed: February 20, 2019
    Date of Patent: August 11, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Ching-Huang Lu, Ashish Baraskar, Vinh Diep
  • Patent number: 10741251
    Abstract: A non-volatile memory system comprises a memory structure and a control circuit connected to the memory structure. The memory structure includes one or more planes of non-volatile memory cells. Each plane is divided into a plurality of partial planes. The control circuit is configured to write to and read from the memory cells by writing a partial page into a particular partial plane and reading the partial page from the particular partial plane using a set of parameters optimized for the particular partial plane.
    Type: Grant
    Filed: April 17, 2018
    Date of Patent: August 11, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Mohan V Dunga, Pitamber Shukla
  • Patent number: 10741257
    Abstract: A method and system are provided for reading a non-transitory memory array. When a default read operation is performed and has failed, a dynamic sensing bit line voltage (VBLC) enhanced read or a dynamic sense time read is performed. According to the dynamic VBLC enhanced read or the dynamic sense time enhanced read, the VBLC or the sense time is increased, and a read is performed with the increased VBLC or increased sense time. If this enhanced read is unsuccessful, and if a maximum VBLC or a maximum sense time has not yet been reached, the VBLC or the sense time is increased again, and another read is performed. Once the maximum VBLC or a maximum sense time has been reached, if the read is still not successful, a read failure is reported.
    Type: Grant
    Filed: June 26, 2019
    Date of Patent: August 11, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Jianzhi Wu, Xiang Yang
  • Patent number: 10741585
    Abstract: A content addressable memory cell is provided that includes a vertical transistor having a gate oxide that includes a ferroelectric material.
    Type: Grant
    Filed: June 29, 2018
    Date of Patent: August 11, 2020
    Assignee: SanDisk Technologies LLC
    Inventor: Christopher J. Petti
  • Patent number: 10734073
    Abstract: A monolithic three-dimensional memory array is provided that includes a plurality of global bit lines disposed above a substrate, a plurality of vertically-oriented bit lines disposed above the global bit lines, a plurality of word lines disposed above the global bit lines, a plurality of memory cells coupled between the vertically-oriented bit lines and the word lines, and a plurality of isolation elements coupled between the vertically-oriented bit lines and the global bit lines. Each isolation element includes a vertical thin-film transistor and a threshold selector device.
    Type: Grant
    Filed: February 12, 2019
    Date of Patent: August 4, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Abhijit Bandyopadhyay, Christopher J. Petti, Brian Le
  • Patent number: 10732856
    Abstract: An exemplary method to rank blocks of a non-volatile memory device includes: for each of a plurality of blocks of a memory device, determining a respective erase health metric (EHM) for each of the blocks by combining an erase difficulty metric and an age metric, including: calculating the erase difficulty metric for a respective block based on erase performance metrics obtained during erase phases of an erase operation performed on the respective block, and determining the age metric for the respective block based on a total number of erase operations performed on the respective block during its lifespan. After determining the respective EHM for each of the blocks, the method includes ranking blocks in accordance with the determined respective EHMs, and selecting a block of the plurality of blocks in accordance with the rankings, and writing data to the selected block.
    Type: Grant
    Filed: October 4, 2016
    Date of Patent: August 4, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Nian Niles Yang, Alexandra Bauche
  • Patent number: 10734081
    Abstract: A method for implementing pulse-amplitude modulation on a memory device includes configuring a first resistor of a first memory die to a first resistance value. The method also includes configuring a second resistor of a second memory die to a second resistance value. The method also includes receiving, during performance of a read operation, in parallel: two voltage values from the first memory die; and two voltage values from the second memory die. The method also includes determining a first data bit value using the two voltage values from the first memory die. The method also includes determining a second data bit value using the two voltage values from the second memory die.
    Type: Grant
    Filed: June 26, 2019
    Date of Patent: August 4, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Nimrod Blatt, Gennady Burdo, Tal Hamias
  • Patent number: 10733047
    Abstract: An apparatus includes memory cells programmed to one of a plurality of data states, wherein the memory cells are configured such that the plurality of data states comprise an error-prone data state. Sense circuitry of the apparatus is configured to sense first memory cells programmed to the error-prone data state, determine a bit encoding for the first memory cells, sense other memory cells programmed to other data states, and determine a bit encoding for the other memory cells. A communication circuit of the apparatus is configured to communicate the bit encoding for the other memory cells, the bit encoding for the first memory cells, and an indication that the first memory cells are programmed to the error-prone data state, in response to a single read command from a controller.
    Type: Grant
    Filed: September 28, 2018
    Date of Patent: August 4, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Mostafa El Gamal, Jim Fitzpatrick