Patents Assigned to SanDisk Technologies LLC
  • Patent number: 12105137
    Abstract: To provide more test data during the manufacture of non-volatile memories and other integrated circuits, machine learning is used to generate virtual test values. Virtual test results are interpolated for one set of tests for devices on which the test is not performed based on correlations with other sets of tests. In one example, machine learning determines a correlation study between bad block values determined at die sort and photo-limited yield (PLY) values determined inline during processing. The correlation can be applied to interpolate virtual inline PLY data for all of the memory dies, allowing for more rapid feedback on the processing parameters for manufacturing the memory dies and making the manufacturing process more efficient and accurate. In another set of embodiments, the machine learning is used to extrapolate limited metrology (e.g., critical dimension) test data to all of the memory die through interpolated virtual metrology data values.
    Type: Grant
    Filed: June 28, 2021
    Date of Patent: October 1, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Yusuke Ikawa, Tsuyoshi Sendoda, Kei Samura, Masaaki Higashitani
  • Patent number: 12106790
    Abstract: A magnetoresistive memory cell includes a magnetoresistive layer stack containing a reference layer, a nonmagnetic spacer layer, and a free layer. A ferroelectric material layer having two stable ferroelectric states is coupled to a strain-modulated ferromagnetic layer to alter a sign of magnetic exchange coupling between the strain-modulated ferromagnetic layer and the free layer. The strain-modulated ferromagnetic layer may be the reference layer or a perpendicular magnetic anisotropy layer that is located proximate to the ferroelectric material layer. The magnetoresistive memory cell may be configured as a three-terminal device or as a two-terminal device, and may be configured as a tunneling magnetoresistance (TMR) device or as a giant magnetoresistance (GMR) device.
    Type: Grant
    Filed: March 24, 2022
    Date of Patent: October 1, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Alan Kalitsov, Derek Stewart, Ananth Kaushik, Gerardo Bertero
  • Patent number: 12108597
    Abstract: A semiconductor structure includes a memory die bonded to a logic die. The memory die includes an alternating stack of insulating layers and electrically conductive layers, a semiconductor material layer located on a distal surface of the alternating stack, a dielectric spacer layer located on a distal surface of the semiconductor material layer, memory opening fill structures vertically extending through the alternating stack, through the semiconductor material layer, and at least partly through the dielectric spacer layer, and a source layer located on a distal surface of the dielectric spacer layer and contacting pillar portions of the vertical semiconductor channels that are embedded within the dielectric spacer layer.
    Type: Grant
    Filed: March 2, 2022
    Date of Patent: October 1, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Teruo Okina, Shinsuke Yada, Ryo Yoshimoto
  • Patent number: 12105963
    Abstract: An apparatus includes a control circuit configured to connect to NAND strings that are connected to bit lines, where each bit line is connected to a plurality of NAND strings in a corresponding plurality of regions of a block. The control circuit is configured to apply a read voltage in read operations directed to NAND strings of the plurality of regions of the block and subsequently adjust the read voltage by a first predetermined amount for read operations directed to NAND strings of a first region of the block. The control circuit is further configured to adjust the read voltage by a second predetermined amount for read operations directed to NAND strings of a second region of the block. The first and second predetermined amounts are based on respective locations of the first and second regions in the block.
    Type: Grant
    Filed: September 8, 2022
    Date of Patent: October 1, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Yi Song, Jiahui Yuan, Yanjie Wang
  • Publication number: 20240321379
    Abstract: Non-volatile memory cells are programmed by raising a voltage applied to a selected word line to a program voltage during a first time period of a programming process for selected non-volatile memory cells connected to the selected word line; programming the selected non-volatile memory cells using the program voltage during a second time period after the first time period; testing, during the first time period, whether the voltage applied to the selected word line is greater than one or more intermediate voltages; and elongating the first time period during the first time period if the voltage applied to the selected word line is not greater than one or more of the intermediate voltages.
    Type: Application
    Filed: July 26, 2023
    Publication date: September 26, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Sai Gautham Thoppa, Parth Amin, Long Pham
  • Publication number: 20240319888
    Abstract: In NAND memory, data sanitization allows a relatively small unit of data (e.g., less than a block) to be effectively destroyed by increasing threshold voltages of memory cells from their programmed threshold voltage to the highest threshold state. To reduce the amount of disturb on memory cells not selected for data sanitization, prior to applying a program voltage to a target word line, a hole based pre-charge operation is performed. More specifically, for NAND strings having a memory cell selected for data sanitation, prior to applying a programming pulse to the corresponding word line, a soft erase operation is performed. After biasing the memory cells and select gates of the NAND strings to a low voltage, a soft erase voltage pulse is applied to the source lines and bit line to pre-charge the NAND string channels with holes.
    Type: Application
    Filed: July 3, 2023
    Publication date: September 26, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Wei Cao, Jiacen Guo, Xiang Yang
  • Publication number: 20240321371
    Abstract: An apparatus is provided that includes a memory cell having a reversible resistance-switching memory element coupled in series with a selector element. The selector element has a first resistance. The resistance-switching memory element is configured to reversibly switch between a second resistance and a third resistance. The memory cell may be selectively configured as either a re-writeable memory cell or a one-time programmable memory cell. The memory cell functions as a one-time programmable memory cell regardless of whether the resistance-switching memory element has the second resistance, the third resistance, or is electrically shorted.
    Type: Application
    Filed: July 19, 2023
    Publication date: September 26, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Deniz Bozdag, Juan P. Saenz, Dimitri Houssameddine, Mark Lin
  • Publication number: 20240319905
    Abstract: A memory system performs an erase process for the non-volatile memory cells including performing erase verify for the non-volatile memory cells. The erase verify comprises comparing threshold voltages of the non-volatile memory cells to an erase verify reference voltage and determining whether an amount of the non-volatile memory cells having a threshold voltage greater than the erase verify reference voltage is less than an allowed bit count. During the erase process, the system compares threshold voltages of the non-volatile memory cells to an intermediate reference voltage that is greater than the erase verify reference voltage and determines an amount of non-volatile memory cells having threshold voltages greater than the intermediate reference voltage. The Allowed Bit Count is increased (during the erase process) by the amount of non-volatile memory cells having threshold voltages greater than the intermediate reference voltage.
    Type: Application
    Filed: July 25, 2023
    Publication date: September 26, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Longju Liu, Yi Song, Sarath Puthenthermadam, Jiahui Yuan
  • Patent number: 12101936
    Abstract: A method of forming a three-dimensional memory device includes forming an alternating stack of insulating layers and sacrificial material layers over a substrate, forming a memory opening extending through the alternating stack, forming a sacrificial memory opening fill structure in the memory opening, replacing the sacrificial material layers with electrically conductive layers, removing the sacrificial memory opening fill structure selective to the electrically conductive layers, and forming a memory opening fill structure the memory opening after replacing the sacrificial material layers with electrically conductive layers and after removing the sacrificial memory opening fill structure. The memory opening fill structure includes a memory film and a vertical semiconductor channel.
    Type: Grant
    Filed: November 10, 2021
    Date of Patent: September 24, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Tatsuya Hinoue, Yusuke Mukae, Ryousuke Itou, Masanori Tsutsumi, Akio Nishida, Ramy Nashed Bassely Said
  • Patent number: 12099728
    Abstract: In order to lower the peak and average current through the channel (thereby lowering peak and average power consumption) during program-verify, which exhibits a word line dependency, the inventors propose to program dummy memory cells connected to a dummy word line before programming data memory cells connected to a data word line. The additional resistance in the NAND string introduced by the preprogrammed dummy memory cells will cause the peak current, and power consumption, to be lower. To address the word line dependency, the dummy memory cells connected to the dummy word line can be programmed to different threshold voltages based on which data word line is to be programmed. Thus, prior to programming data non-volatile memory cells connected to a particular data word line, the dummy memory cells are programmed to a threshold voltage that is chosen based on the position of the particular data word line.
    Type: Grant
    Filed: September 28, 2022
    Date of Patent: September 24, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Towhidur Razzak, Ravi Kumar, Abu Naser Zainuddin, Jiahui Yuan
  • Patent number: 12100461
    Abstract: To remedy short term data retention issues, a system creates a gate to channel voltage differential for non-volatile memory cells between programming and verifying in order to accelerate the effects of the short term data retention issue. That is, the gate to channel voltage differential will accelerate the migrating of electrons out of shallow traps. In some embodiments, the gate to channel voltage differential comprises a higher voltage at the channel in comparison to the gate. In some embodiments, the programming comprises applying doses of a programming signal and the gate to channel voltage differential is only created for a subset of the time periods between doses of the programming signal.
    Type: Grant
    Filed: June 29, 2022
    Date of Patent: September 24, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Yi Song, Jiacen Guo, Jiahui Yuan
  • Patent number: 12100458
    Abstract: Systems and methods are provided for correcting errors in unmatched memory devices. Various embodiments herein train a memory interface to determine a duty cycle timing for a clock signal in a data window formed by a data signal in a memory cell. The duty cycle timing identifies an initial trained timing in the data window at which a setup portion and a hold portion of the data window are approximately equal in length when the trigger signal is received at the initial trained timing. The embodiments herein also identify an event that shifts the duty cycle timing away from the initial trained timing, and triggers a retraining of the memory interface based on a determination that at least one of two points defined about the initial trained timing fails a two-point sampling.
    Type: Grant
    Filed: May 27, 2022
    Date of Patent: September 24, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Venkatesh Prasad Ramachandra, Jang Woo Lee, Srinivas Rajendra, Anil Pai
  • Patent number: 12093812
    Abstract: An MRAM-based vector multiplication device, such as can be used for inferencing in a neural network, is presented that is ultralow power, low cost, and does not require special on-chip programming. A crosspoint array has an MRAM cell at each crosspoint junction and periphery array circuitry capable of supplying independent input voltages to each word line and reading current on each bit line. Vector multiplication is performed as an in-array multiplication of a vector of input voltages with matrix weight values encoded by the MRAM cell states. The MRAM cells can be individually programmed using a combination of input voltages and an external magnetic field. The external magnetic field is chosen so that a write voltage of one polarity reduces the anisotropy sufficiently to align the cell state with the external field, but is insufficient to align the cell if only half of the write voltage is applied.
    Type: Grant
    Filed: October 2, 2020
    Date of Patent: September 17, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Michael Grobis, Michael Nicolas Albert Tran
  • Patent number: 12094537
    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: September 17, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Yi Song, Dengtao Zhao, Sarath Puthenthermadam, Jiahui Yuan
  • Patent number: 12094943
    Abstract: A semiconductor structure includes an alternating stack of insulating layers and electrically conductive layers, a memory opening vertically extending through the alternating stack, and a memory opening fill structure located in the memory opening and including a vertical semiconductor channel, a memory film in contact with the vertical semiconductor channel, and a vertical stack of tubular dielectric spacers laterally surrounding the memory film. The tubular dielectric spacers may include tubular graded silicon oxynitride portions having a composition gradient such that an atomic concentration of nitrogen decreases with a lateral distance from an outer sidewall of the memory film, or may include tubular composite dielectric spacers including a respective tubular silicon oxide spacer and a respective tubular dielectric metal oxide spacer. Each of the electrically conductive layers has a hammerhead-shaped vertical cross-sectional profile.
    Type: Grant
    Filed: January 28, 2022
    Date of Patent: September 17, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Tomohiro Kubo, Yuki Kasai
  • Patent number: 12094944
    Abstract: A field effect transistor includes a gate dielectric and a gate electrode overlying an active region and contacting a sidewall of a trench isolation structure. The transistor may be a fringeless transistor in which the gate electrode does not overlie a portion of the trench isolation region. A planar dielectric spacer plate and a conductive gate cap structure may overlie the gate electrode. The conductive gate cap structure may have a z-shaped vertical cross-sectional profile to contact the gate electrode and to provide a segment overlying the planar dielectric spacer plate. Alternatively or additionally, a conductive gate connection structure may be provided to provide electrical connection between two electrodes of adjacent field effect transistors.
    Type: Grant
    Filed: May 10, 2021
    Date of Patent: September 17, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Dai Iwata, Hiroshi Nakatsuji, Hiroyuki Ogawa, Eiichi Fujikura
  • Patent number: 12096632
    Abstract: Two types of support pillar structures are formed in a staircase region of an alternating stack of insulating layers and sacrificial material layers. First-type support pillar structures are formed in areas distal from backside trenches to be subsequently formed, and second-type support pillar structures may be formed in areas proximal to the backside trenches. The second-type support pillar structures may be formed as dielectric support pillar structures, or may be formed with at least one additional dielectric spacer.
    Type: Grant
    Filed: April 29, 2021
    Date of Patent: September 17, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Koichi Matsuno, Johann Alsmeier
  • Patent number: 12096636
    Abstract: A semiconductor structure includes semiconductor devices located over a substrate, bit lines electrically connected to the semiconductor devices and having a respective reentrant vertical cross-sectional profile within a vertical plane that is perpendicular to a lengthwise direction along which the bit lines laterally extend, and dielectric portions that are interlaced with the bit lines along a horizontal direction that is perpendicular to the lengthwise direction. The dielectric portions may contain air gaps. A bit-line-contact via structure can be formed on top of a bit line. In some embodiments, dielectric cap strips may be located on top surface of the dielectric portions and may cover peripheral regions of the top surfaces of the bit lines without covering middle regions of the top surfaces of the bit lines.
    Type: Grant
    Filed: September 20, 2021
    Date of Patent: September 17, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Adarsh Rajashekhar, Raghuveer S. Makala, Rahul Sharangpani, Fei Zhou
  • Patent number: 12094546
    Abstract: In order to decrease the width of threshold voltage distributions of programmed memory cells without unreasonably increasing the time needed to complete programming, a non-volatile memory uses a zone based program speed adjustment. The non-volatile memory starts programming a first set of the non-volatile memory cells until a minimum number of memory cells of the first set of non-volatile memory cells reach a first threshold voltage. In response to the minimum number of memory cells reaching the first threshold voltage, the first set of non-volatile memory cells are categorized into zones/groups based on threshold voltage. The speed of programming is then adjusted differently for each zone/group and programming is completed for the first set of non-volatile memory cells.
    Type: Grant
    Filed: January 31, 2022
    Date of Patent: September 17, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Yi Song, Jiahui Yuan, Yanjie Wang
  • Patent number: 12093069
    Abstract: Systems and methods are provided for generating a stable DC reference voltage that has low sensitivity to operating temperature and supply voltage variations and is stable across process corners using complimentary metal-on-semiconductor field-effect transistors (MOSFETS). In an example implementation, a reference voltage generator circuit is provided that includes complimentary MOSFETs including a first complimentary MOSFET connected to a first node and having a first threshold voltage, and a second complimentary MOSFET connected to a second node and having a second threshold voltage that is greater than the first threshold voltage. The reference voltage generator circuit feeds the first node a first current based on mirroring a second current at the second node and outputs a stable DC reference voltage based on the first and second complimentary MOSFETs and configured operating in respective saturation regions.
    Type: Grant
    Filed: September 6, 2022
    Date of Patent: September 17, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Mohammad Reza Mahmoodi, Martin Lueker-Boden