Patents Assigned to SanDisk Technologies LLC
  • Patent number: 11925027
    Abstract: A semiconductor structure includes a memory array including first and second bit lines and a sense amplifier circuit. The sense amplifier circuit includes a first sense amplifier array containing first active sense amplifier transistors that each have an active region having a first width, where the first active sense amplifier transistors are electrically connected to the first bit lines, and a second sense amplifier array including second active sense amplifier transistors that each have the active region having the first width, where the second active sense amplifier transistors are electrically connected to the second bit lines, and dummy active regions which are electrically inactive located between columns of the second active sense amplifier transistors.
    Type: Grant
    Filed: December 27, 2021
    Date of Patent: March 5, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Takuma Takimoto, Masayuki Hiroi, Hiroyuki Ogawa, Masatoshi Okumura
  • Patent number: 11923321
    Abstract: A memory die includes dielectric isolation rails embedded within a substrate semiconductor layer, laterally spaced apart along a first horizontal direction, and each laterally extending along a second horizontal direction that is perpendicular to the first horizontal direction, and alternating stacks of insulating layers and electrically conductive layers located over the substrate semiconductor layer. The alternating stacks are laterally spaced apart along the second horizontal direction by line trenches that laterally extend along the first horizontal direction. Arrays of memory stack structures are provided such that each array of memory stack structures among the arrays of memory stack structures vertically extends through a respective alternating stack. Each of the memory stack structures includes a respective vertical stack of memory elements and a respective vertical semiconductor channel.
    Type: Grant
    Filed: January 12, 2022
    Date of Patent: March 5, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Shin Sakiyama, Genta Mizuno, Kenzo Iizuka, Takayuki Yokoyama, Toshiyuki Sega
  • Patent number: 11923019
    Abstract: The present disclosure provides for improving data retention reliability. During a programming operation associated with a memory cell, after the memory cell passes verification of a first verification voltage level, a second verification voltage level can be applied to the memory cell. Based on a comparison of the voltage in the memory cell with the second verification voltage level, a bit line voltage may be applied. Based on the applied bit line voltage, fast bits associated with the memory cell can be upshifted to an upper portion of a final voltage distribution associated with the programming operation. Upshifting the fast bits counteracts the downshifting effect in a final voltage distribution that may be caused by charge leakage or electron loss.
    Type: Grant
    Filed: February 14, 2022
    Date of Patent: March 5, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Xiaojia Jia, Swaroop Kaza, Laidong Wang, Jiacen Guo
  • Publication number: 20240071529
    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: Application
    Filed: August 30, 2022
    Publication date: February 29, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Jiacen Guo, Dengtao Zhao, Xiang Yang
  • Publication number: 20240071482
    Abstract: Technology is disclosed herein for mixed lockout verify. In a first programming phase, prior to a pre-determined data state completing verification, a no-lockout program verify is performed. After the pre-determined data state has completed verification, a lockout program verify is performed. The no-lockout verify may include charging all bit lines associated with the group to a sensing voltage to perform. The lockout verify may include selectively charging to the sensing voltage only bit lines associated with memory cells in the group to be verified. Bit lines associated with memory cells in the group that are not to be verified may be grounded to perform the lockout verify. The lockout verify saves considerable current and/or power. However, performing the lockout verify during the first programming phase may slow performance due to a need to scan the content in a remote set of data latches.
    Type: Application
    Filed: August 25, 2022
    Publication date: February 29, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Xiang Yang, Hua-Ling Cynthia Hsu
  • Publication number: 20240071533
    Abstract: An apparatus is provided that includes a block of memory cells having a NAND string that includes a first select transistor, 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 based on the first count a first drain-to-gate voltage of the first select transistor, wherein the first drain-to-gate voltage is configured to cause the first select transistor to generate a first gate-induced drain leakage current, and applying a first erase pulse to the first select transistor based on the determined first drain-to-gate voltage.
    Type: Application
    Filed: August 31, 2022
    Publication date: February 29, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Yihang Liu, Xiaochen Zhu, Lito De La Rama, Feng Gao
  • Publication number: 20240071509
    Abstract: The techniques include a memory device receiving a data write instruction. The memory device programs the memory cells of the memory blocks to a one bit per memory cell (SLC) format with a first and second SLC data states. In response to the data programmed to the memory cells of the memory blocks reaching an SLC limit prior to completion of the data write instruction, without erasing the memory cells, the memory device programs at least some of the memory cells from the SLC format to a two bits per memory cell (MLC) format. When programming from the SLC format to the MLC format, the memory device inhibits programming of some of the memory cells in the first and second SLC data states to form a first MLC data state and programs other memory cells of the SLC data states to form second, third, and fourth MLC data states.
    Type: Application
    Filed: August 29, 2022
    Publication date: February 29, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Xiang Yang, Jiacen Guo, Shubhajit Mukherjee
  • Publication number: 20240071544
    Abstract: To reduce spikes in the current used by a NAND memory die, different ramp rates are used for the pass voltage applied to unselected word lines during a program operation depending on whether data is stored in a multi-level cell (MLC) format or in a single level cell (SLC) format. These ramp rates can be determined through device characterization and stored as parameter values on the memory die. Different ramp rate interval values can also be used for the pass voltage applied to unselected word lines during a program operation depending on whether data is stored in an MLC format or in an SLC format.
    Type: Application
    Filed: August 29, 2022
    Publication date: February 29, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Abu Naser Zainuddin, Jiahui Yuan, Dong-il Moon
  • Publication number: 20240071525
    Abstract: A memory apparatus and operating method are provided. The apparatus includes memory cells connected to word lines and disposed in memory holes and configured to retain a threshold voltage. The memory holes are organized in rows grouped in strings and the strings comprise a plurality of blocks which comprise planes. A control means is configured to program the memory cells connected to one of the word lines and associated with one of the strings in each of the plurality of planes and acquire a smart verify programming voltage individually for each of the planes in a smart verify operation. The control means concurrently programs at least some of the memory cells connected to each of the word lines in each of the planes in a program operation using the smart verify programming voltage individually acquired for each of the planes in the smart verify operation.
    Type: Application
    Filed: August 25, 2022
    Publication date: February 29, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Ke Zhang, Liang Li
  • Publication number: 20240071508
    Abstract: The memory device includes a plurality of memory blocks, each including a plurality of memory cells arranged in a plurality of word lines. Control circuitry is in communication with the plurality of memory blocks. In operation, the control circuitry receives a data write instruction and programs the memory cells of the memory blocks to a one bit per memory cell (SLC) format. In response to the data programmed to the memory cells of the memory blocks in the SLC format reaching an SLC limit prior to completion of the data write instruction, without erasing the memory cells programmed to the SLC format, the control circuitry programs the memory cells of at least some of the plurality of memory blocks from the SLC format to a two bits per memory cell (MLC) format.
    Type: Application
    Filed: August 26, 2022
    Publication date: February 29, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Xiang Yang, Jiacen Guo, Takayuki Inoue
  • Publication number: 20240071493
    Abstract: To reduce spikes in the current used by a NAND memory die, different ramp rates for different regions, or zones, of word lines are used for the pass voltage applied to unselected word lines during a program operation. The properties of the word lines, such as their resistance and capacitance (RC) values, vary across the NAND memory array. By determining the RC values of the word lines across the array, the word lines can be broken into multiple zones based on these properties. The zones can then be individually assigned different ramp rates for applying a pass voltage to the unselected word lines, where a parameter for the ramp rates can be stored as a register value on the memory die.
    Type: Application
    Filed: August 29, 2022
    Publication date: February 29, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Abu Naser Zainuddin, Jiahui Yuan, Towhidur Razzak
  • Publication number: 20240071527
    Abstract: A 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. A controller, coupled to the non-volatile memory, configured to: determine, based on a stage of a product lifetime of the non-volatile memory, a negative word line setting for implementing during performance of a first operation; perform the first operation, the first operation including adjusting, based on the negative word line setting, a negative word line relative parameter; determine, based on another stage of the product lifetime of the non-volatile memory, another negative word line setting for implementing during performance of a second operation; and perform the second operation, the second operation including adjusting, based on the other negative word line setting, another negative word line relative parameter.
    Type: Application
    Filed: August 26, 2022
    Publication date: February 29, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Xiaoyu Che, Yanjie Wang, Runchen Fang
  • Publication number: 20240071433
    Abstract: An apparatus includes a control circuit that is configured to connect to an array of non-volatile memory cells. The control circuit includes a first plurality of data latches configured to connect to non-volatile memory cells of a first plane and a second plurality of data latches configured to connect to non-volatile memory cells of a second plane. The control circuit also includes a shared data transfer data latch configured for transfer of data with the first plurality of data latches and the second plurality of data latches.
    Type: Application
    Filed: August 31, 2022
    Publication date: February 29, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Hua-Ling Cynthia Hsu, YenLung Li, Siddarth Naga Murty Bassa, Jeongduk Sohn
  • Publication number: 20240071526
    Abstract: A memory apparatus and operating method are provided. The apparatus includes memory cells connected to word lines and disposed in strings and configured to retain a threshold voltage corresponding to data states. A control means is configured to program and verify the memory cells during a program operation. The memory cells associated with predetermined ones of the data states are not verified until the memory cells associated with specific prior ones of the data states finish programming to define verify windows ranging between each one of the specific prior ones of the data states and each one of the predetermined ones. The control means adjusts the verify windows in response to the memory cells associated with one of the specific prior ones of the data states not finishing programming before the one of the predetermined ones of the at least one of the verify windows is verified.
    Type: Application
    Filed: August 25, 2022
    Publication date: February 29, 2024
    Applicant: SanDisk Technologies LLC
    Inventor: Kazuki Yamauchi
  • Publication number: 20240071524
    Abstract: Technology is disclosed herein for smart verify in a memory system that has a four bit per cell program mode (or X4 mode) and also a three bit per cell program mode (or X3 mode). The X3 mode uses a three-bit gray code that is based on a four-bit gray code of the X4 mode. The memory system skips verify of states in the X3 mode, while using a considerable portion of the programming logic from the X4 mode. In one X3 mode the memory system skips B-state verify while the number of memory cells having a Vt above an A-state verify voltage is below a threshold. In one X3 mode the memory system determines whether to skip verify for a first set of data states based on a first test and determines whether to skip verify for a second set of data states based on a second test.
    Type: Application
    Filed: August 25, 2022
    Publication date: February 29, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Xiang Yang, Henry Chin, Erika Penzo, Muhammad Masuduzzaman
  • Publication number: 20240069803
    Abstract: The memory device has a plurality of memory blocks including a plurality of memory cells arranged in a plurality of word lines. The memory device also includes control circuitry that is in communication with the plurality of memory blocks. The control circuitry is configured to receive a data write instruction. The control circuitry is further configured to program the memory cells of the memory blocks to an SLC format. In response to the data programmed to the memory cells of the memory blocks in the SLC format reaching an SLC limit prior to completion of the data write instruction, without erasing the memory cells programmed to the SLC format, the control circuitry is configured to program the memory cells of at least some of the plurality of memory blocks from the SLC format to a TLC format.
    Type: Application
    Filed: August 30, 2022
    Publication date: February 29, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Xiang Yang, Wei Cao
  • Patent number: 11916549
    Abstract: Improved voltage level shifters are disclosed capable of achieving substantially higher data transfer speeds with reduced static current than existing cross-coupled voltage level shifters. The voltage level shifters disclosed herein include first stage that translates input voltage signals received from a core circuitry in a first voltage domain to intermediate output voltage signals an intermediate voltage domain, and second stage circuitry that translates the intermediate output voltage signals received from the first stage circuitry in the intermediate voltage domain to output voltage signals in a second voltage domain. The disclosed voltage level shifters are scalable to support various logic voltage levels in the second voltage domain.
    Type: Grant
    Filed: August 29, 2022
    Date of Patent: February 27, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Shiv Harit Mathur, Sai Ravi Teja Konakalla
  • Patent number: 11915769
    Abstract: A non-volatile memory device includes a control circuit configured to connect to a bit line that is connected to one or more non-volatile memory cells. The control circuit includes a first plurality of data latches connected to a first local data bus to store first program-verify pass/fail bits and a second plurality of data latches connected to a second local data bus to store second program-verify pass/fail bits for second non-volatile memory cells. The non-volatile memory device further includes a shared isolation latch and one or more interface circuits connected to the first local data bus and the second local data bus. The one or more interface circuits are configured to selectively block the first program-verify pass/fail bits from the first plurality of latches and the second program-verify pass/fail bits from the second plurality of latches according to an indicator bit stored in the shared isolation latch.
    Type: Grant
    Filed: May 16, 2022
    Date of Patent: February 27, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Kei Kitamura, Iris Lu, Tai-Yuan Tseng
  • Patent number: 11907545
    Abstract: For a non-volatile memory that uses hard bit and soft bit data in error correction operations, to reduce the amount of soft bit data that needs to be transferred from a memory to the controller and improve memory system performance, the soft bit data can be compressed before transfer. After the soft bit data is read and stored into the internal data latches associated with the sense amplifiers, it is compressed within these internal data latches. The compressed soft bit data can then be transferred to the transfer data latches of a cache buffer, where the compressed soft bit data can be consolidated and transferred out over an input-output interface. Within the input-output interface, the compressed data can be reshuffled to put into logical user data order if needed.
    Type: Grant
    Filed: April 28, 2022
    Date of Patent: February 20, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: YenLung Li, Siddarth Naga Murty Bassa, Chen Chen, Hua-Ling Cynthia Hsu
  • Patent number: 11907200
    Abstract: Apparatuses, systems, methods, and computer program products are disclosed for persistent memory management. Persistent memory management may include replicating a persistent data structure in volatile memory buffers of at least two non-volatile storage devices. Persistent memory management may include preserving a snapshot copy of data in association with completion of a barrier operation for the data. Persistent memory management may include determining which interface of a plurality of supported interfaces is to be used to flush data from a processor complex.
    Type: Grant
    Filed: September 29, 2020
    Date of Patent: February 20, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Nisha Talagala, Swaminathan Sundararaman, David Flynn