Patents Assigned to SanDisk Technologies LLC
  • Patent number: 11894067
    Abstract: A memory apparatus and method of operation are provided. The memory apparatus includes memory cells configured to retain a threshold voltage. The memory cells are connected to one of a plurality of word lines and are arranged in strings comprising a plurality of blocks. A control means is coupled to the plurality of word lines and the strings and is configured to periodically determine a read frequency metric associated with a plurality of read operations of one of the plurality of blocks of the memory cells. The control means is also configured to relocate data of the one of the plurality of blocks and cause the one of the plurality of blocks to remain unused for a predetermined relaxation time based on the read frequency metric.
    Type: Grant
    Filed: December 15, 2021
    Date of Patent: February 6, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Xiang Yang, Abhijith Prakash, Shubhajit Mukherjee
  • Patent number: 11894051
    Abstract: A memory apparatus and method of operation are provided. The apparatus includes memory cells each connected to one of a plurality of word lines. The memory cells are disposed in strings and configured to retain a threshold voltage corresponding to one of a plurality of data states. A control means is coupled to the plurality of word lines and the strings and is configured to apply a read voltage to a selected ones of the plurality of word lines during a read operation and ramp down to a discharge voltage at an end of the read operation and apply a ready voltage to the selected ones of the plurality of word lines during a ready period of time following the read operation. The control means is also configured to adjust at least one of the discharge voltage and the ready voltage based on a temperature of the memory apparatus.
    Type: Grant
    Filed: May 24, 2022
    Date of Patent: February 6, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Dong-Il Moon, Abhijith Prakash, Wei Zhao, Henry Chin
  • Patent number: 11894068
    Abstract: A non-volatile memory combines a hard bit and a soft bit read into a single, efficient soft sense sequence by using two sense per state level to improve read time efficiency. Rather than a standard hard bit read, where two soft bit reads are performed, offset above and below the hard bit read value, the hard bit read is shifted so that it reliable senses one state but less reliably senses the other state and soft bit data is only determined for the less reliably sensed state. This reduces the amount of soft bit data. The efficient soft sense sequence can be used as a default read mode, providing soft bit information for ECC correction without triggering a read error handling flow. Merging the soft bit and hard bit sense into one sequence can avoid extra overhead for read sequence operations.
    Type: Grant
    Filed: December 21, 2021
    Date of Patent: February 6, 2024
    Assignee: SanDisk Technologies LLC
    Inventor: Hua-Ling Cynthia Hsu
  • Patent number: 11894072
    Abstract: A memory apparatus and method of operation are provided. The apparatus includes memory cells connected to word lines and disposed in strings. A control means is coupled to the word lines and the strings and is configured to ramp a voltage applied to a selected one of the word lines from a verify voltage to a reduced voltage during a program-verify portion of a program operation. The control means successively ramps voltages applied to each of a plurality of neighboring ones of the word lines from a read pass voltage to the reduced voltage beginning with ones of the plurality of neighboring ones of the word lines immediately adjacent the selected one of the word lines and progressing to ones of the plurality of neighboring others of the word lines disposed increasingly remotely from the selected one of the word lines during the program-verify portion of the program operation.
    Type: Grant
    Filed: April 20, 2022
    Date of Patent: February 6, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Jiacen Guo, Xiang Yang, Abhijith Prakash
  • Patent number: 11894062
    Abstract: A memory apparatus and method of operation are provided. The apparatus includes apparatus including memory cells connected to word lines including at least one dummy word line and data word lines. The memory cells are arranged in strings and are configured to retain a threshold voltage. The apparatus also includes a control means coupled to the word lines and the strings and configured to identify ones of the memory cells connected to the at least one dummy word line with the threshold voltage being below a predetermined detection voltage threshold following an erase operation. The control means is also configured to selectively apply at least one programming pulse of a maintenance program voltage to the at least one dummy word line to program the ones of the memory cells connected to the at least one dummy word line having the threshold voltage being below the predetermined detection voltage threshold.
    Type: Grant
    Filed: August 10, 2021
    Date of Patent: February 6, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Xiang Yang, Deepanshu Dutta, Gerrit Jan Hemink, Shubhajit Mukherjee
  • Patent number: 11894071
    Abstract: A system has been described that performs differential temperature compensation based on a differential between the temperature at time of programming and temperature at time of reading for a set of data. Differential temperature compensation is useful for bulk programming/reading (e.g., many pages of data) and/or programming/reading super pages of data (multiple pages residing on different memory die).
    Type: Grant
    Filed: December 13, 2021
    Date of Patent: February 6, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Yi Song, Dengtao Zhao, Sarath Puthenthermadam, Jiahui Yuan
  • Patent number: 11894056
    Abstract: A three dimensional non-volatile memory structure includes word lines connected to non-volatile memory cells arranged in blocks. A plurality of word line switches are connected to the word lines and one or more sources of voltage. The word line switches are arranged in groups of X word line switches such that each group of X word line switches is positioned in a line under Y blocks of non-volatile memory cells and has a length that is equal to the width of the Y blocks of non-volatile memory cells, where X>Y.
    Type: Grant
    Filed: February 22, 2022
    Date of Patent: February 6, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Shiqian Shao, Fumiaki Toyama
  • Patent number: 11894080
    Abstract: An apparatus disclosed herein comprises: a plurality of memory cells and a control circuit coupled to the plurality of memory cells. The control circuit is configured to: acquire a first set of read levels on a wordline of a first block of pages of memory cells; acquire a second set of read levels on a first wordline of a second block of pages of a second set of memory cells in response to determining that the fail bit count of the page after a read operation is above the threshold amount; and acquire a third set of read levels on a second wordline of the second block in response to determining that the fail bit count of the page after the second read operation is above the threshold amount.
    Type: Grant
    Filed: April 29, 2022
    Date of Patent: February 6, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Erika Penzo, Henry Chin, Jie Liu, Dong-Il Moon
  • Publication number: 20240038315
    Abstract: An apparatus is provided that includes a block including a word line coupled to a plurality of memory cells, and a control circuit coupled to the word line. The control circuit is configured to program the plurality of memory cells by applying program pulses to the word line in a plurality of program loops, determining a first count of a number of the program loops used to complete programming a first subset of the plurality of memory cells to a first programmed state, first comparing the first count to a corresponding first lower limit and a corresponding first upper limit, and determining whether programming the plurality of memory cells has failed based on a result of the first comparing step.
    Type: Application
    Filed: July 26, 2022
    Publication date: February 1, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Yi Song, Sarath Puthenthermadam, Jiahui Yuan
  • Publication number: 20240036740
    Abstract: A non-volatile memory system separately performs a memory operation for multiple sub-blocks of a block in order from previously determined slowest sub-block of the block to a previously determined faster sub-block of the block. As a slower sub-block is more likely to fail, this order of is more likely to identify a failure earlier in the process thereby saving time and reducing potential for a disturb. In some embodiments, the proposed order of operation can be used in conjunction with a programming process that concurrently programs blocks in multiple planes using completion of programming of a fastest plane to a data state as a trigger to test for program failure of other planes to the data state.
    Type: Application
    Filed: November 9, 2022
    Publication date: February 1, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Yihang Liu, Xiaochen Zhu, Jie Liu, Sarath Puthenthermadam, Jiahui Yuan, Feng Gao
  • Patent number: 11887670
    Abstract: Apparatuses and techniques are described for controlling a bit line pre-charge voltage in a program operation based on a number of bits per cell, with a goal to reduce peak current consumption. In one aspect, the ramp up of a bit line voltage to an inhibit level is optimized according to the number of bits per cell. The ramp up can involve increasing the bit line voltage from an initial level to a target voltage at a regulated rate, then increasing the bit line voltage from the target voltage to a final voltage at an unregulated rate. In one approach, the regulated ramp rate is less for single-level cell programming compared to multi-level cell programming. The target voltage can also be optimized based on the number of bis per cell.
    Type: Grant
    Filed: August 19, 2021
    Date of Patent: January 30, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Yu-Chung Lien, Deepanshu Dutta, Jiahui Yuan
  • Patent number: 11889684
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over at least one source layer, and groups of memory opening fill structures vertically extending through the alternating stack. Each memory opening fill structure can include a vertical stack of memory elements and a vertical semiconductor channel. A plurality of source-side select gate electrodes can be laterally spaced apart by source-select-level dielectric isolation structures. Alternatively or additionally, the at least one source layer may include a plurality of source layers. A group of memory opening fill structures can be selected by selecting a source layer and/or by selecting a source-level electrically conductive layer.
    Type: Grant
    Filed: November 18, 2020
    Date of Patent: January 30, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Masanori Tsutsumi, Shinsuke Yada, Mitsuteru Mushiga, Akio Nishida, Hiroyuki Ogawa, Teruo Okina
  • Patent number: 11887677
    Abstract: The memory device includes a controller that is configured to program the memory cells of a selected word line in a plurality of program-verify iterations. During a verify portion at least one of the program-verify iterations, the controller determines a threshold voltage of at least one memory cell relative to a first verify low voltage VL1, a second verify low voltage VL2, and a verify high voltage VH associated with a data state being programmed. The controller also maintains a count of program-verify iterations since the at least one memory cell passed a verify high voltage of a previously programmed data state or discharges a sense node through a channel including the at least one memory cell and compares a discharge time to predetermined sense times associated with the first and second verify low voltages and with the verify high voltage.
    Type: Grant
    Filed: March 22, 2022
    Date of Patent: January 30, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Muhammad Masuduzzaman, Deepanshu Dutta, Gerrit Jan Hemink
  • Patent number: 11889694
    Abstract: A memory die includes an alternating stack of insulating layers and electrically conductive layers through which memory opening fill structures vertically extend. The memory die includes at least three memory array regions interlaced with at least two contact regions, or at least three contact regions interlaced with at least two memory array regions in the same memory plane. A logic die including at least two word line driver regions can be bonded to the memory die. The interlacing of the contact regions and the memory array regions can reduce lateral offset of boundaries of the word line driver regions from boundaries of the contact regions.
    Type: Grant
    Filed: August 9, 2021
    Date of Patent: January 30, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Hardwell Chibvongodze, Zhixin Cui, Rajdeep Gautam, Hiroyuki Ogawa
  • Patent number: 11887674
    Abstract: A memory apparatus and method of operation is provided. The apparatus includes memory cells each connected to one of a plurality of word lines. The memory cells are disposed in strings coupled to one of a plurality of bit lines and are configured to retain a threshold voltage corresponding to one of a plurality of data states. A control means is configured to read each of the memory cells in a read operation. For each one of the memory cells, the control means is also configured to offset at least one of a bit line settling time and a kick voltage during the read operation based on a probability of at least one neighboring one of the plurality of bit lines being coupled to the memory cells retaining the threshold voltage corresponding to a different one of the plurality of data states than the one of the memory cells.
    Type: Grant
    Filed: March 29, 2022
    Date of Patent: January 30, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Yanjie Wang, Guirong Liang, Xiaoyu Che, Yi Song
  • Publication number: 20240029806
    Abstract: In a non-volatile memory system that performs programming of selected memory cells (in coordination with pre-charging and boosting of channels for unselected memory cells) and program-verify to determine whether the programming was successful, the system transitions from program-verify to the next dose of programming by concurrently lowering a voltage applied to a selected word line and voltages applied to word lines on a first side of the selected word line at the conclusion of program-verify. Subsequent to lowering the voltage applied to the selected word line, the system successively lowers voltages applied to groups of one or more word lines on a second side of the selected word line at the conclusion of program-verify beginning with a group of one or more word lines immediately adjacent the selected word line and progressing to other groups of one or more word lines disposed increasingly remote from the selected word line.
    Type: Application
    Filed: July 25, 2022
    Publication date: January 25, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Jiacen Guo, Peng Zhang, Xiang Yang, Yanli Zhang
  • Publication number: 20240029789
    Abstract: The memory die that includes a plurality of memory blocks. Each memory block includes a plurality of memory cells that are configured to store three bits of data in each memory cell when the memory die is in a TLC operating mode. The memory die has a non-binary data capacity, which is a multiple of 683 Gb, when the memory die is operating in the TLC operating mode.
    Type: Application
    Filed: July 21, 2022
    Publication date: January 25, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Xiang Yang, Deepanshu Dutta
  • Publication number: 20240029804
    Abstract: An apparatus is provided that includes a block of memory cells and a control circuit coupled to the block of memory cells. The control circuit is configured to perform an erase operation on the block of memory cells by determining a first count of a number of times that the block of memory cells previously has been programmed and erased, determining a threshold number based on the first count, and determining whether the erase operation passed or failed based on the threshold number.
    Type: Application
    Filed: July 20, 2022
    Publication date: January 25, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Yi Song, Xiaochen Zhu, Jiahui Yuan, Lito De La Rama
  • Patent number: 11882706
    Abstract: A memory array is provided that includes a plurality of word lines and a plurality of bit lines, and a plurality of memory cells each including a corresponding magnetic memory element coupled in series with a corresponding selector element. Each memory cell is coupled between one of the word lines and one of the bit lines. Each memory cell has a half-pitch F, and comprises an area between 2F2 and 4F2.
    Type: Grant
    Filed: June 22, 2021
    Date of Patent: January 23, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Lei Wan, Tsai-Wei Wu, Jordan A. Katine
  • Patent number: 11881271
    Abstract: To save power during a read process, NAND strings of each sub-block of a block have independently controlled source side select lines connected to source side select gates and drain side select lines connected to drain side select gates so that NAND strings of unselected sub-blocks can float and not draw current. To prevent read disturb in NAND strings of unselected sub-blocks, after all word lines are raised to a pass gate voltage, unselected word lines nearby the selected word line are lowered to respective intermediate voltages while lowering the voltage on the selected word line in order to achieve a channel potential gradient in the floated NAND strings of the unselected sub-blocks that does not result in read disturb. Subsequently, the selected word line is raised to the appropriate read compare voltage so the selected memory cells can be sensed.
    Type: Grant
    Filed: May 31, 2022
    Date of Patent: January 23, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Jiacen Guo, Xiang Yang, Xiaochen Zhu