Patents Assigned to SanDisk Technologies LLC
  • Patent number: 11972815
    Abstract: The memory device includes a controller that is configured to program a plurality of memory cells of a selected word line in a plurality of programming loops and count the number of programming loops to complete programming. The controller is also configured to compare the number of programming loops to complete programming of the memory cells of the selected word line to at least one of a predetermined upper limit and a predetermined lower limit to determine if a plane containing the selected word line is at an elevated risk for read failure. In response to the controller making a determination that the plane containing the selected word line is at an elevated risk for read failure, the controller is configured to conduct a post write read operation at least one word line of the plurality of word lines.
    Type: Grant
    Filed: May 10, 2022
    Date of Patent: April 30, 2024
    Assignee: SanDisk Technologies, LLC
    Inventors: Ke Zhang, Minna Li, Li Liang
  • Patent number: 11972809
    Abstract: A non-volatile semiconductor memory device includes non-volatile storage elements and one or more control circuits in communication with the non-volatile storage elements. The one or more control circuits are configured to determine for a program iteration of a program operation on a word line whether a condition is met and in response to determining that the condition is met, identify one or more memory cells of the word line that are in an erased state that have a threshold voltage higher than an erase threshold voltage and perform the program iteration of the program operation. The program iteration includes applying a first bitline inhibit voltage to bitlines connected to the identified one or more memory cells and a second bitline inhibit voltage to bitlines connected to one or more memory cells that are in the erased state that do not have a threshold voltage higher than the erase threshold voltage.
    Type: Grant
    Filed: February 28, 2022
    Date of Patent: April 30, 2024
    Assignee: SanDisk Technologies, LLC
    Inventors: Sujjatul Islam, Yu-Chung Lien, Ravi Kumar, Xue Pitner
  • Patent number: 11972812
    Abstract: A memory system identifies memory cells connected to a common word line that have had their threshold voltage unintentionally drift lower than programmed by determining whether memory cells meet two criteria: (1) the memory cells have threshold voltages within an offset of a read compare voltage of a data state; and (2) adjacent memory cells (connected to word lines that are adjacent to the common word line) are in one or more low data states. For those memory cells meeting the two criteria, the memory system performs some amount of programming on the memory cells to refresh the data stored in those memory cells to be as originally intended.
    Type: Grant
    Filed: December 13, 2021
    Date of Patent: April 30, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Yi Song, Jiahui Yuan, Jun Wan, Deepanshu Dutta
  • Patent number: 11972787
    Abstract: Technology is disclosed herein for refreshing threshold switching selectors in programmable resistance memory cells in cross-point memory arrays. The Vt of the threshold switching selector may drift over time. The memory system resets the Vt of the threshold switching selectors with a selector refresh operation and uses a separate data refresh operation to refresh data in programmable resistance memory elements. The data refresh operation itself may also refresh the selector. However, the threshold switching selector refresh operation is faster than the data refresh operation. Moreover, the selector refresh operation consumes much less power and/or current then the data refresh operation. The selector refresh operation may thus be performed at a higher rate than the data refresh operation.
    Type: Grant
    Filed: May 25, 2022
    Date of Patent: April 30, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Michael Nicolas Albert Tran, Michael K. Grobis, Ward Parkinson, Nathan Franklin
  • Patent number: 11972822
    Abstract: Technology is disclosed for a fast ECC engine for a mixed read of MRAM cells. A codeword read from MRAM cells using a referenced read is decoded using a first ECC mode. If decoding passes, results are provided to a host. If decoding fails, a self-referenced read (SRR) is performed. The data read using the SRR is decoded with a second ECC mode that is capable of correcting a greater number of bits than the first ECC mode. The second ECC mode may have a higher mis-correction rate than the first ECC mode (for a given raw bit error rate (RBER)). However, the RBER may be lower when using the second ECC mode. Therefore, the first and second ECC modes may result in about the same probability of an undetectable error (or mis-correction).
    Type: Grant
    Filed: December 15, 2021
    Date of Patent: April 30, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Martin Hassner, Michael Nicolas Albert Tran, Ward Parkinson, Michael Grobis, Nathan Franklin, Raj Ramanujan
  • Patent number: 11972819
    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: Grant
    Filed: July 25, 2022
    Date of Patent: April 30, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Jiacen Guo, Peng Zhang, Xiang Yang, Yanli Zhang
  • Patent number: 11972820
    Abstract: Memory cells are arranged as NAND strings to form a block divided into sub-blocks, and each NAND string includes a dummy memory cell connected to a dummy word line. Memory cells are programmed by applying programming pulses to a selected word line in a selected sub-block with program-verify performed between pulses. Unselected NAND strings are inhibited from programming by boosting channels of the unselected NAND strings in the selected sub-block from a positive pre-charge voltage to a boosted voltage. The pre-charging of the channels of unselected NAND strings is performed while lowering voltages at the end of program-verify by applying overdrive voltages to data word lines in a sub-block closer to the source line than the selected sub-block and lowering to a resting voltage a dummy word line between the sub-blocks prior to lowering to a resting voltage the data word lines in the sub-block closer to the source line.
    Type: Grant
    Filed: August 30, 2022
    Date of Patent: April 30, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Jiacen Guo, Dengtao Zhao, Xiang Yang
  • Patent number: 11973026
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, memory openings located in a memory array region and vertically extending through the alternating stack, memory opening fill structures located in the memory openings, and laterally-isolated contact via assemblies located in a contact region. Each of the laterally-isolated contact via assemblies includes a contact via structure contacting a top surface of a respective one of the electrically conductive layers and an insulating spacer laterally surrounding the contact via structure and having an outer surface having a corrugated vertical cross-sectional profile in which first portions of the insulating spacer located at levels of the electrically conductive layers laterally protrude outward relative to second portions of the insulating spacer located at levels of the insulating layers.
    Type: Grant
    Filed: March 2, 2022
    Date of Patent: April 30, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Michiaki Sano, Koichi Ito
  • Patent number: 11973044
    Abstract: An integrated memory assembly comprises a control die bonded to a memory die. The memory die includes multiple non-volatile memory structures (e.g., planes, arrays, groups of blocks, etc.), each comprising a stack of alternating conductive and dielectric layers forming staircases at one or more edges of the non-volatile memory structures. The non-volatile memory structures are positioned with gaps between the non-volatile memory structures such that the gaps separate the staircases of adjacent non-volatile memory structures. Metal interlayer segments positioned in the gaps are connected to a top metal layer positioned above non-volatile memory structures and to one or more electrical circuits on the control die via zero, one or more other metal layers/segments.
    Type: Grant
    Filed: December 23, 2021
    Date of Patent: April 30, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Shiqian Shao, Fumiaki Toyama, Tuan Pham
  • Patent number: 11972817
    Abstract: A memory apparatus and method of operation are provided. The apparatus includes memory cells connected to word lines. The memory cells are disposed in strings and are configured to retain a threshold voltage corresponding to data states. A control means is configured to apply verification pulses of program verify voltages each associated with one of the data states to selected ones of the word lines to determine whether the memory cells connected thereto have the threshold voltage above each of the program verify voltages associated with the data states targeted for each of the memory cells being programmed during verify loops of a program-verify operation. The control means slows the memory cells targeted for a selected one of the data states identified as being faster to program than other ones of the memory cells during one of verify loops associated with an earlier one of data states.
    Type: Grant
    Filed: June 10, 2022
    Date of Patent: April 30, 2024
    Assignee: SanDisk Technologies, LLC
    Inventors: Ke Zhang, Ming Wang, Liang Li
  • Patent number: 11971829
    Abstract: For a non-volatile memory that uses hard bit and a soft bit data in error correction operations, an on-the-fly compression scheme is used for the soft bit data. As soft bit data is transferred to a memory's input-output interface, the soft bit data is compressed prior to transmission to the an ECC engine memory controller, while hard bit data is transferred in un-compressed form.
    Type: Grant
    Filed: December 21, 2021
    Date of Patent: April 30, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Hua-Ling Cynthia Hsu, A. Harihara Sravan, YenLung Li
  • Patent number: 11971826
    Abstract: For a non-volatile memory that uses hard bit and a soft bit data in error correction operations, architectures are introduced for the compression of the soft bit data to reduce the amount of data transferred over the memory's input-output interface. For a memory device with multiple planes of memory cells, the internal global data bus is segmented and a data compression circuit associated with each segment. This allows soft bit data from a cache buffer of a plane using one segment to transfer data between the cache buffer and the associated compression circuit concurrently with transferring data from a cache buffer of another plane using another segment, either for compression or transfer to the input-output interface.
    Type: Grant
    Filed: December 21, 2021
    Date of Patent: April 30, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Hua-Ling Cynthia Hsu, A. Harihara Sravan, YenLung Li
  • Publication number: 20240136001
    Abstract: A memory system programs memory cells connected to a selected word line by applying doses of programming and performing program-verify between doses. An efficient and low current program-verify operation includes: while scanning the results of a previous program-verify operation, ramp up voltages on the select lines for the next program-verify operation without waiting for the scan to complete and ramp up voltages on unselected word lines for the next program-verify operation following a step signal (so that voltage applied to the unselected word lines rise in steps) without waiting for the scan to complete.
    Type: Application
    Filed: July 23, 2023
    Publication date: April 25, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Abu Naser Zainuddin, Jiahui Yuan, Toru Miwa
  • Patent number: 11968826
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers, memory openings extending through the alternating stack, and memory opening fill structures located in the memory openings and containing a respective vertical semiconductor channel and a respective memory film. Each of the electrically conductive layers includes a tubular metallic liner in contact with a respective outer sidewall segment of a respective one of the memory opening fill structures, an electrically conductive barrier layer contacting the respective tubular metallic liner and two of the insulating layers, and a metallic fill material layer contacting the electrically conductive barrier layer, and not contacting the tubular metallic liner or any of the insulating layers. The memory opening fill structures are formed after performing a halogen outgassing anneal through the memory openings to reduce or eliminate the halogen outgassing damage in the layers of the memory film.
    Type: Grant
    Filed: April 29, 2021
    Date of Patent: April 23, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Ramy Nashed Bassely Said, Raghuveer S. Makala, Senaka Kanakamedala, Rahul Sharangpani
  • Patent number: 11968827
    Abstract: An alternating stack of insulating layers and sacrificial material layers is formed over a substrate. The sacrificial material layers include a stack of word-line-level sacrificial material layers and at least one drain-select-level sacrificial material layer. Drain-select-level openings are formed through the at least one drain-select-level sacrificial material layer, which is replaced with at least one drain-select-level electrically conductive layer. Memory openings are formed by vertically extending the drain-select-level openings through the word-line-level sacrificial material layers. Memory opening fill structures are formed within the memory openings. The word-line-level sacrificial material layers are replaced with word-line-level electrically conductive layers.
    Type: Grant
    Filed: September 2, 2021
    Date of Patent: April 23, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventor: Tatsuya Hinoue
  • Patent number: 11968834
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, memory openings vertically extending through the alternating stack and having lateral protrusions at levels of the electrically conductive layers, and memory opening fill structures located in the memory openings. Each of the memory opening fill structures includes a vertical semiconductor channel, a dielectric material liner laterally surrounding the vertical semiconductor channel, and a vertical stack of discrete memory elements laterally surrounding the dielectric material liner and located within volumes of the lateral protrusions. Each discrete memory element includes a vertical inner sidewall and a convex or stepped outer sidewall.
    Type: Grant
    Filed: March 4, 2021
    Date of Patent: April 23, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Ramy Nashed Bassely Said, Raghuveer S. Makala, Senaka Kanakamedala, Fei Zhou
  • Patent number: 11968825
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and word-line-level electrically conductive layers located over a substrate, and a vertical layer stack located over the alternating stack, the vertical layer stack including an insulating cap layer, drain select electrodes, and a drain-select-level insulating layer. The drain select electrodes are laterally spaced apart from each other by drain-select-level isolation structures. Memory stack structures including a respective vertical semiconductor channel and a respective memory film vertically extend through the alternating stack and the vertical layer stack. Each of the vertical semiconductor channels includes a word-line-level semiconductor channel portion extending through the alternating stack, a connection channel portion contacting a top end of the word-line-level semiconductor channel, and a drain-select-level semiconductor channel portion vertically extending through the vertical layer stack.
    Type: Grant
    Filed: December 18, 2020
    Date of Patent: April 23, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Zhen Chen, Yanli Zhang
  • Patent number: 11968839
    Abstract: A memory device includes a semiconductor channel, a gate electrode, and a stack located between the semiconductor channel and the gate electrode. The stack includes, from one side to another, a first ferroelectric material portion, a second ferroelectric material portion, and a gate dielectric portion that contacts the semiconductor channel.
    Type: Grant
    Filed: September 6, 2022
    Date of Patent: April 23, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Yanli Zhang, Johann Alsmeier
  • Patent number: 11966621
    Abstract: Technology is disclosed for a non-volatile memory system that decouples dataload from program execution. A memory controller transfers data for a program operation and issues a first type of program execution command. When in a coupled mode, the die programs the data in response to the first type of program execution command. When in a decoupled mode, rather than program the data into non-volatile memory cells the die enters a wait state. Optionally, the memory controller can instruct another die to execute a memory operation while the first die is in the wait state. In response to receiving a second type of program execution command from the memory controller when in the wait state, the first die will program the data into non-volatile memory cells. The memory controller may issue the second type of program execution command in response to determining that sufficient power resources (or thermal budget) exist.
    Type: Grant
    Filed: February 17, 2022
    Date of Patent: April 23, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Hua-Ling Cynthia Hsu, Aaron Lee
  • Patent number: 11967626
    Abstract: A field effect transistor includes at least one line trench extending downward from a top surface of a channel region which laterally surrounds or underlies the at least one line trench, a gate dielectric contacting all surfaces of the at least one line trench and including a planar gate dielectric portion that extends over an entirety of a top surface of the channel region, a gate electrode, a source region, and a drain region.
    Type: Grant
    Filed: September 14, 2021
    Date of Patent: April 23, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Mitsuhiro Togo, Takashi Kobayashi, Sudarshan Narayanan