Patents Assigned to SanDisk Technologies LLC
  • Patent number: 11227663
    Abstract: Methods for reducing read disturb using NAND strings with poly-silicon channels and p-type doped source lines are described. During a boosted read operation for a selected memory cell transistor in a NAND string, a back-gate bias or bit line voltage may be applied to a bit line connected to the NAND string and a source line voltage greater than the bit line voltage may be applied to a source line connected to the NAND string; with these bias conditions, electrons may be injected from the bit line and annihilated in the source line during the read operation. To avoid leakage currents through NAND strings in non-selected memory blocks, the threshold voltages of source-side select gate transistors of the NAND strings may be set to a negative threshold voltage that has an absolute voltage value greater than the source line voltage applied during the read operation.
    Type: Grant
    Filed: February 10, 2021
    Date of Patent: January 18, 2022
    Assignee: SanDisk Technologies LLC
    Inventors: Kiyohiko Sakakibara, Ippei Yasuda, Ken Oowada, Masaaki Higashitani
  • Patent number: 11226772
    Abstract: Power and/or current regulation in non-volatile memory systems is disclosed. Peak power/current usage may be reduced by staggering concurrent program operations in the different semiconductor dies. Each set of one or more semiconductor dies has an earliest permitted start time for its program operation, as well as a number of permitted backup start times. The permitted start times are unique for each set of one or more semiconductor dies. There may be a uniform gap or delay between each permitted start time. If a semiconductor die is busy with another memory operation at or after its earliest permitted start time, then the program operation is initiated or resumed at one of the permitted backup times. By having permitted backup times, the memory system need not poll each semiconductor die to determine whether the semiconductor die is ready/busy in order to determine when a die should start a program operation.
    Type: Grant
    Filed: June 25, 2020
    Date of Patent: January 18, 2022
    Assignee: SanDisk Technologies LLC
    Inventors: Yu-Chung Lien, Mark Murin, Hua-Ling Cynthia Hsu, Tomer Eliash, Huai-Yuan Tseng, Deepanshu Dutta
  • Patent number: 11222678
    Abstract: In a memory array with a cross-point structure, at each cross-point junction a programmable resistive memory element, such as an MRAM device, is connected in series with a threshold switching selector, such as an ovonic threshold switch. In a two-layer cross-point structure with such memory cells, the MRAM devices in one layer are inverted relative to the MRAM devices in the other layer. This can allow for the transient voltage spike placed across the MRAM device when the threshold switching selector first turns on in a sensing operation to dissipate more rapidly, reducing the risk of changing a stored data state before it can be sensed.
    Type: Grant
    Filed: October 2, 2020
    Date of Patent: January 11, 2022
    Assignee: SanDisk Technologies LLC
    Inventors: Ward Parkinson, James O'Toole, Nathan Franklin, Thomas Trent
  • Patent number: 11222694
    Abstract: A storage device is disclosed herein. The storage device, comprises: a non-volatile memory including control circuitry and an array of memory cells formed using a set of word lines and a set of bit lines; and a reference current generator circuit configured to receive an input voltage from a voltage supply and generate therefrom a plurality of outputs, each output of the plurality of outputs used to generate one or more bias voltages/currents for one or more control signals. The control circuitry is configured to: receive a refresh read operation command; and adapt operation of the reference current generator circuit based on receiving the refresh read operation command. This proposal is also applicable for other test modes, such as SA stress, soft and preprogram, and SA test modes.
    Type: Grant
    Filed: August 5, 2020
    Date of Patent: January 11, 2022
    Assignee: SanDisk Technologies LLC
    Inventors: Sirisha Bhamidipati, Arka Ganguly, Ohwon Kwon, Chia-Kai Chou, Kou Tei
  • Patent number: 11222954
    Abstract: A three-dimensional memory device includes an alternating stack of word-line-isolation insulating layers and word-line-level electrically conductive layers located over a substrate, a plurality of drain-select-level electrodes that are laterally spaced apart from each other overlying the alternating stack, memory stack structures containing a respective vertical semiconductor channel laterally surrounded by a respective memory film and vertically extending through the alternating stack and the plurality of drain-select-level electrodes, inter-select-gate electrodes located between a respective neighboring pair of the drain-select-level electrodes, and inter-select-gate dielectrics located between each of the inter-select-gate electrodes and a neighboring one of the drain-select-level electrodes. The inter-select-gate electrodes are not electrically connected to the drain-select-level electrodes.
    Type: Grant
    Filed: March 24, 2020
    Date of Patent: January 11, 2022
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Zhixin Cui, Hardwell Chibvongodze, Masatoshi Nishikawa
  • Patent number: 11222881
    Abstract: A memory device includes a memory die containing memory elements, a support die containing peripheral devices and bonded to the memory die, and an electrically conductive path between two of the peripheral devices which extends at least partially through the memory die. The electrically conductive path is electrically isolated from the memory elements.
    Type: Grant
    Filed: June 12, 2020
    Date of Patent: January 11, 2022
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Yanli Zhang, Kwang-Ho Kim, Johann Alsmeier
  • Patent number: 11217532
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate and memory stack structures extending through the alternating stack. Each of the electrically conductive layers includes a stack of a compositionally graded diffusion barrier and a metal fill material portion, and the compositionally graded diffusion barrier includes a substantially amorphous region contacting the interface between the compositionally graded diffusion barrier and a substantially crystalline region that is spaced from the interface by the amorphous region. The substantially crystalline region effectively blocks atomic diffusion, and the amorphous region induces formation of large grains during deposition of the metal fill material portions.
    Type: Grant
    Filed: June 27, 2018
    Date of Patent: January 4, 2022
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Rahul Sharangpani, Raghuveer S. Makala, Fei Zhou, Adarsh Rajashekhar, Tatsuya Hinoue, Tomoyuki Obu, Tomohiro Uno, Yusuke Mukae
  • Publication number: 20210407613
    Abstract: An integrated memory assembly comprises a memory die and a control die bonded to the memory die. The memory die includes a memory structure of non-volatile memory cells. The control die is configured to program user data to and read user data from the memory die based on one or more operational parameters. The control die is configured to calibrate the one or more operational parameters for the memory die. The control die is also configured to perform testing of the memory die using the calibrated one or more operational parameters.
    Type: Application
    Filed: June 24, 2020
    Publication date: December 30, 2021
    Applicant: SANDISK TECHNOLOGIES LLC
    Inventors: Tomer Eliash, Alexander Bazarsky, Eran Sharon
  • Publication number: 20210405891
    Abstract: An apparatus includes a controller and a plurality of memory dies operable connected to and controlled by the controller. Each of the memory dies draws a current from a current source during a program operation. The controller being configured to receive a clock signal from each of the memory dies; count the number of clock signal received to determine a count value; and dynamically stagger at least one of the memory dies relative to the other memory dies when the count value reaches a maximum count value within a threshold time. The controller operates to dynamically stagger operation of at least one memory die to prevent the group of memory dies from operating synchronously.
    Type: Application
    Filed: June 30, 2020
    Publication date: December 30, 2021
    Applicant: SanDisk Technologies LLC
    Inventors: Yu-Chung Lien, Deepanshu Dutta, Huai-Yuan Tseng
  • Publication number: 20210405920
    Abstract: Power and/or current regulation in non-volatile memory systems is disclosed. Peak power/current usage may be reduced by staggering concurrent program operations in the different semiconductor dies. Each set of one or more semiconductor dies has an earliest permitted start time for its program operation, as well as a number of permitted backup start times. The permitted start times are unique for each set of one or more semiconductor dies. There may be a uniform gap or delay between each permitted start time. If a semiconductor die is busy with another memory operation at or after its earliest permitted start time, then the program operation is initiated or resumed at one of the permitted backup times. By having permitted backup times, the memory system need not poll each semiconductor die to determine whether the semiconductor die is ready/busy in order to determine when a die should start a program operation.
    Type: Application
    Filed: June 25, 2020
    Publication date: December 30, 2021
    Applicant: SanDisk Technologies LLC
    Inventors: Yu-Chung Lien, Mark Murin, Hua-Ling Cynthia Hsu, Tomer Eliash, Huai-Yuan Tseng, Deepanshu Dutta
  • Publication number: 20210408024
    Abstract: A memory device disclosed herein. The memory device comprises: a memory string including a first select transistor, a memory cell transistor, and a second select transistor connected in series; a bit line connected to one end of the first select transistor; a source line connected to one end of the second select transistor; a first select line connected to a gate of the first select transistor; a word line connected to a gate of the memory cell transistor; a second select line connected to a gate of the second select transistor; and a control circuit configured to perform, before a program operation, a pre-charge operation comprising: applying a voltage to the second select line connected to the gate of the second select transistor to cause gate-induced drain leakage from the second select transistor.
    Type: Application
    Filed: June 30, 2020
    Publication date: December 30, 2021
    Applicant: SanDisk Technologies LLC
    Inventors: Sarath Puthenthermadam, Yanli Zhang, Huai-yuan Tseng, Peng Zhang
  • Publication number: 20210406672
    Abstract: Non-volatile memory structures for performing compute in memory inferencing for neural networks are presented. To improve performance, both in terms of speed and energy consumption, weight matrices are replaced with their singular value decomposition (SVD) and use of a low rank approximations (LRAs). The decomposition matrices can be stored in a single array, with the resultant LRA matrices requiring fewer weight values to be stored. The reduced sizes of the LRA matrices allow for inferencing to be performed more quickly and with less power. In a high performance and energy efficiency mode, a reduced rank for the SVD matrices stored on a memory die is determined and used to increase performance and reduce power needed for an inferencing operation.
    Type: Application
    Filed: June 26, 2020
    Publication date: December 30, 2021
    Applicant: SanDisk Technologies LLC
    Inventors: Tung Thanh Hoang, Won Ho Choi, Martin Lueker-Boden
  • Publication number: 20210407603
    Abstract: An apparatus includes a memory controller configured to apply selected one or ones of the program verify voltage levels to a single tier of memory cells. A memory controller is configured to: program data into the plurality of memory cells; and perform a program verify operation across multiple voltage levels with a first voltage level of the program verify operation being applied to a single tier that represents all of the tiers in the memory group and a second voltage level of the program verify operation being applied to multiple tiers, wherein the first voltage level is less than the second voltage level. In embodiments, less than all of the tiers, e.g.
    Type: Application
    Filed: June 29, 2020
    Publication date: December 30, 2021
    Applicant: SanDisk Technologies LLC
    Inventors: Yu-Chung Lien, Dengtao Zhao, Huai-Yuan Tseng
  • Publication number: 20210407604
    Abstract: A storage device for verifying whether memory cells have been programmed. The storage device may be configured to use a verification technique, that is part of a set of verification techniques, to verify data states of a set of memory cells of a selected word line. The one or more verification techniques may be utilized based on an iteration of the verify operation that is to be performed. The storage device may be further configured to perform, using the verification technique, a next iteration of the program-verify operation to verify whether one or more memory cells have been programmed. Using the verification technique and performing the next-iteration of the program-verify operation are to be repeated until the set of memory cells have been verified.
    Type: Application
    Filed: June 30, 2020
    Publication date: December 30, 2021
    Applicant: SanDisk Technologies LLC
    Inventor: Hiroki Yabe
  • Publication number: 20210407596
    Abstract: An apparatus, disclosed herein, comprises a plurality of planes, each plane of the plurality of planes including a plurality of memory cells and a control circuit coupled to the plurality of memory cells. The control circuit is configured to: determine a position of a program loop in a sequence of program loops performed to complete a programming operation; initiate an inhibit bit line ramping event for the first plane including ramping of a set of bit lines of a first plane up to an inhibit voltage and based on the position of the program loop, initiate an inhibit bit line ramping event with a ramping start time delay for a second plane, where the inhibit bit line ramping event for the second plane includes initiating ramping of a set of bit lines of the second plane up to the inhibit voltage after the ramping start time delay.
    Type: Application
    Filed: June 26, 2020
    Publication date: December 30, 2021
    Applicant: SanDisk Technologies LLC
    Inventors: Yu-Chung Lien, Hua-Ling Hsu, Huai-Yuan Tseng
  • Publication number: 20210407605
    Abstract: Apparatus and methods are described to program memory cells and verify stored values programmed into the cells. The next stage in stored memory can be moved to the current verification iteration when certain conditions are met. Verification can include counting bits that exceed a voltage value for a stage being verified to produce a bit count number and determining if the bit count number for the stage being verified meets a threshold value. If the bit count number does not meet the threshold, the verification process can continue with a current verify iteration and thereafter move to a next verify iteration. If the bit count number does meet the threshold, the process can add a next stage to the current verify iteration and thereafter move to a next verify iteration.
    Type: Application
    Filed: June 30, 2020
    Publication date: December 30, 2021
    Applicant: SanDisk technologies LLC
    Inventors: Yu-Chung Lien, Fanglin Zhang, Zhuojie Li, Huai-Yuan Tseng
  • Patent number: 11209993
    Abstract: Apparatus and methods implement a physical unclonable function (PUF) from NAND operations. A NAND flash memory device may generate an unclonable natural random sequence of bits based on a threshold voltage of a plurality of cells in a memory cell array. The unclonable natural random sequence may be stored starting at an address of the memory cell array. A selected subsequence of the unclonable natural random sequence may be stored in a first set of data latches, and target data may be stored in a second set of data latches. The NAND flash memory device may generate a physical unclonable function (PUF) output by applying an XOR operation to the target data and the selected subsequence. The PUF output may be stored in a set of registers or provided to a memory controller to be used for secure applications such as secure identity detection and secure data transfer.
    Type: Grant
    Filed: March 24, 2020
    Date of Patent: December 28, 2021
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Yuki Fujita, Kazuto Oku, Kyosuke Matsumoto
  • Patent number: 11211127
    Abstract: An apparatus, disclosed herein, comprises a plurality of planes, each plane of the plurality of planes including a plurality of memory cells and a control circuit coupled to the plurality of memory cells. The control circuit is configured to: determine a position of a program loop in a sequence of program loops performed to complete a programming operation; initiate an inhibit bit line ramping event for the first plane including ramping of a set of bit lines of a first plane up to an inhibit voltage and based on the position of the program loop, initiate an inhibit bit line ramping event with a ramping start time delay for a second plane, where the inhibit bit line ramping event for the second plane includes initiating ramping of a set of bit lines of the second plane up to the inhibit voltage after the ramping start time delay.
    Type: Grant
    Filed: June 26, 2020
    Date of Patent: December 28, 2021
    Assignee: SanDisk Technologies LLC
    Inventors: Yu-Chung Lien, Hua-Ling Hsu, Huai-Yuan Tseng
  • Patent number: 11211132
    Abstract: A memory apparatus and method of operation is provided. The apparatus includes a plurality of memory cells coupled to a control circuit. The control circuit is configured to receive data indicating a data state for each memory cell of a set of memory cells of the plurality of memory cells and program, in multiple programming loops, the set of memory cells according to the data indicating the data state for each memory cell of the set of memory cells. The control circuit is further configured to determine that the programming of the set of memory cells is in a last programming loop of the multiple programming loops and in response to the determination, receive data indicating a data state for each memory cell of another set of memory cells of the plurality of memory cells.
    Type: Grant
    Filed: February 27, 2020
    Date of Patent: December 28, 2021
    Assignee: SanDisk Technologies LLC
    Inventors: Piyush A. Dhotre, Sahil Sharma, Niles Yang, Phil Reusswig
  • Patent number: 11210241
    Abstract: A data storage system includes a storage medium including plurality of memory cells, a storage controller in communication with the storage medium, an electrical interface circuitry configured to pass data via a channel disposed between the storage medium and the storage controller; and voltage training circuitry configured to train a high-level output voltage (VOH) for each of a plurality of data lines of the channel. Training the VOH includes, for each of the plurality of data lines of the channel, calibrating a pull-up driver of the storage controller against an on-die termination circuit of the storage medium, calibrating a pull-down driver of the storage controller against the pull-up driver of the storage controller, and calibrating an on-die termination circuit of the storage controller against a pull-up driver of the storage medium.
    Type: Grant
    Filed: October 13, 2020
    Date of Patent: December 28, 2021
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Nitin Gupta, Ashish Savadia, Jayanth Thimmaiah, Ramakrishnan Subramanian, Rampraveen Somasundaram, Shiv Harit Mathur, Vinayak Ghatawade, Siddesh Darne, Venkatesh Ramachandra, Elkana Richter