Patents Assigned to SanDisk Technologies
  • Patent number: 11837296
    Abstract: A control circuit connected to non-volatile memory cells applies a programming signal to a plurality of the non-volatile memory cells in order to program the plurality of the non-volatile memory cells to a set of data states. The control circuit performs program verification for the non-volatile memory cells, including applying bit line voltages during program verification based on word line position and data state being verified.
    Type: Grant
    Filed: October 19, 2021
    Date of Patent: December 5, 2023
    Assignee: SanDisk Technologies LLC
    Inventors: Yu-Chung Lien, Jiahui Yuan, Ohwon Kwon
  • Publication number: 20230386580
    Abstract: An apparatus that comprises a plurality of memory cells and a control circuit coupled to the plurality of memory cells is disclosed. The control circuit is configured to perform a read operation. The read operation includes determining a read condition of a memory cell, where the read condition is of a plurality of read conditions and determining a boost timing for the memory cell, where the boost timing corresponds to the read condition.
    Type: Application
    Filed: May 25, 2022
    Publication date: November 30, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Peng Wang, Jia Li, Behrang Bagheri, Keyur Payak, Bo Lei, Long Pham, Jun Wan
  • Publication number: 20230386568
    Abstract: A method for programming a memory array of a non-volatile memory structure, wherein the memory array comprises a population of MLC NAND-type memory cells, and the method comprises: (1) in a first program pulse, programming selected memory cells according to a first programmable state and a second programmable state, and (2) in a second program pulse, programming the selected memory cells according to a third programmable state.
    Type: Application
    Filed: May 26, 2022
    Publication date: November 30, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Xiang Yang, Deepanshu Dutta, Muhammad Masuduzzaman, Jiacen Guo
  • Publication number: 20230386543
    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: Application
    Filed: May 25, 2022
    Publication date: November 30, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Michael Nicolas Albert Tran, Michael K. Grobis, Ward Parkinson, Nathan Franklin
  • Publication number: 20230386585
    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: Application
    Filed: May 31, 2022
    Publication date: November 30, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Jiacen Guo, Xiang Yang, Xiaochen Zhu
  • Publication number: 20230386586
    Abstract: The memory device that includes a plurality of memory cells that are arranged in a plurality of word lines. A controller is in electrical communication with the plurality of memory cells. During programming, the controller detects a temperature of the memory device. The controller then programs the memory cells of a selected word line of the plurality of word lines in a plurality of program loops until programming is completed or until the plurality of program loops is greater than a maximum number of program loops. The maximum number of program loops is dependent on the temperature that is detected.
    Type: Application
    Filed: May 27, 2022
    Publication date: November 30, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Sujjatul Islam, Ravi Kumar
  • Publication number: 20230386569
    Abstract: A method for programming a memory array of a non-volatile memory structure, the memory comprising a population of MLC NAND-type memory cells, wherein the method comprises applying: (1) an inhibit condition to one or more bit lines of the memory array, and (2) a zero voltage condition to one or more bit lines of the memory array such that less than half of the adjacent bit lines of the memory array experience a voltage swing between the inhibit condition and the zero voltage condition.
    Type: Application
    Filed: May 26, 2022
    Publication date: November 30, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Xiang Yang, Muhammad Masuduzzaman, Jiacen Guo
  • Patent number: 11830564
    Abstract: Apparatuses and techniques are presented for detecting bit line open circuits and short circuits in a memory device in which a memory die is inverted and bonded to a control die. In one approach, the control die comprises a set of bit lines which are connected to a set of bit lines of the memory die, and the set of bit lines of the control die comprise ground transistors, e.g., transistors connected to a ground node. Ground transistors of even-numbered bit lines may be commonly controlled, while ground transistors of odd-numbered bit lines are commonly controlled. The ground transistors may be controlled to detect open circuits and short circuits in the bit lines of the control die and the memory die. A laser scanning technique can also be used to determine a physical location of a defect of a bit line.
    Type: Grant
    Filed: August 30, 2021
    Date of Patent: November 28, 2023
    Assignee: SanDisk Technologies LLC
    Inventor: Brian Murphy
  • Patent number: 11829281
    Abstract: Technology is disclosed herein for semi receiver side write training in a non-volatile memory system. The transmitting device has delay taps that control the delay between a data strobe signal and data signals sent on the communication bus. The delay taps on the transmitting device are more precise that can typically be fabricated on the receiving device (e.g., NAND memory die). However, the receiving device performs the comparisons between test data and expected data, which alleviates the need to read back the test data. After the different delays have been tested, the receiving device informs the transmitting device of the shortest and longest delays for which data was validly received. The transmitting device then sets the delay taps based on this information. Moreover, the write training can be performed in parallel on many receiving devices, which is very efficient.
    Type: Grant
    Filed: June 16, 2021
    Date of Patent: November 28, 2023
    Assignee: SanDisk Technologies LLC
    Inventors: Jang Woo Lee, Srinivas Rajendra, Anil Pai, Venkatesh Ramachandra
  • Publication number: 20230377643
    Abstract: A controller is configured to program the memory cells to a first set of data states in a first programming pass and to a greater second set of data states in a second programming pass. The controller performs the first programming pass on the first word line. The controller then repeats the process of programming a portion of another word line and then comparing an upper tail of an erased data state of the first word line to a critical voltage until the upper tail of the erased data state of the first word line exceeds the critical voltage by a threshold. In response to the upper tail of the erased data state exceeding the critical voltage by the threshold, the controller then alternates between the first and second programming passes until the first programming pass is completed on the remaining word lines of the memory block.
    Type: Application
    Filed: May 23, 2022
    Publication date: November 23, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Huiwen Xu, Jun Wan, Bo Lei
  • Publication number: 20230377655
    Abstract: The memory device that includes a memory block memory cells arranged in word lines. A controller is in electrical communication with the memory cells and is configured to program the memory cells to a first set of data states in a first programming pass and then to a greater second set of data states in a second programming pass. During programming of a first set of memory cells in at least one of the first and second programming passes, the controller is further configured to determine programming statuses of a second set of memory cells that is adjacent the first set of memory cells. The controller is further configured to read the first set of memory cells using a read voltage that is adjusted from a base read voltage based on the determined programming statuses of the second set of memory cells.
    Type: Application
    Filed: May 18, 2022
    Publication date: November 23, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Huiwen Xu, Nidhi Agrawal, Zhenni Wan, Bo Lei, Jun Wan
  • Publication number: 20230377657
    Abstract: A memory apparatus and method of operation are provided. The apparatus includes memory cells each connected to word lines and disposed in strings and configured to retain a threshold voltage. The memory apparatus also includes a charge pump configured to ramp up to a program voltage in a pump setting process and supply the program voltage to the word lines during a program operation and ramp down from the program voltage in a pump resetting process. A control means is configured to successively apply one of a series of pulses of the program voltage from the charge pump to each selected one of the word lines to program the memory cells during the program operation. The control means is also configured to skip the pump setting process and the pump resetting process of the charge pump in between each of the series of pulses of the program voltage.
    Type: Application
    Filed: May 23, 2022
    Publication date: November 23, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Xiang Yang, Chin-Yi Chen, Deepanshu Dutta
  • Patent number: 11823744
    Abstract: A method of operating a memory device. The method includes the step of preparing a memory device that includes a first group of the memory holes with full SGD transistors and a second group of the memory holes with partial SGD transistors. The second group includes both a set of selected partial SGD transistors and a set of unselected partial SGD transistors. The method proceeds with electrically floating a first unselected partial SGD transistor of the set of unselected partial SGD transistors. With the at least one first unselected partial SGD transistor electrically floating, the method continues with reducing a voltage applied to at least one transistor or memory cell adjacent the first unselected partial SGD transistor such that a voltage of the first unselected partial SGD transistor is decreased through a capacitance coupling effect.
    Type: Grant
    Filed: September 28, 2021
    Date of Patent: November 21, 2023
    Assignee: SanDisk Technologies LLC
    Inventor: Xiang Yang
  • Publication number: 20230368850
    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: erase a block; verify, using a first erase verify level, that the block was properly erased; verify, using a second erase verify level, that the block was properly erased; determine whether there are any mismatches in a plurality of verify statuses between neighboring wordlines of the block from verifying the block using the second erase verify level; and identify, based on the determination, whether the block has failed.
    Type: Application
    Filed: May 10, 2022
    Publication date: November 16, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Huiwen Xu, Bo Lei, Jun Wan
  • Publication number: 20230368847
    Abstract: Technology is disclosed herein for a memory system that regulates charge pump current during a ramp up of the output voltage. The memory systems operates the charge pump in a current regulation mode while the charge pump output voltage ramps up. After the output voltage crosses a threshold voltage, the charge pump is operated in a voltage regulation mode in which the output voltage is regulated to a target output voltage. In one aspect, the memory system generates a random duty cycle clock in the current regulation mode. The memory system determines a target duty cycle for the random duty cycle clock that will regulate the input current of the charge pump to a target current, given the present output voltage. A clock based on the random duty cycle clock is provided to a clock input of the charge pump to regulate the charge pump current.
    Type: Application
    Filed: May 11, 2022
    Publication date: November 16, 2023
    Applicant: SanDisk Technologies LLC
    Inventor: Hiroki Yabe
  • Publication number: 20230368852
    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: Application
    Filed: May 16, 2022
    Publication date: November 16, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Kei Kitamura, Iris Lu, Tai-Yuan Tseng
  • Publication number: 20230368851
    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: Application
    Filed: May 10, 2022
    Publication date: November 16, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Ke Zhang, Minna Li, Li Liang
  • Publication number: 20230367944
    Abstract: The memory device includes a die with a first set of planes and a second set of planes. The planes are rectangular in shape with a major dimension and a minor dimension. The die includes a CMOS layer with at least one common peripheral circuitry area, and each of the planes includes a non-common peripheral circuitry area in the CMOS layer. Each plane of the first set of planes is oriented such that its major dimension extends in a first direction, and each plane of the second set of planes is oriented such that its major dimension extends in a second direction that is different than the first direction such that the non-common peripheral circuitry area of each plane is immediately adjacent the at least one common peripheral circuitry area in the CMOS layer.
    Type: Application
    Filed: May 10, 2022
    Publication date: November 16, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Yuki Mizutani, Masaaki Higashitani
  • Publication number: 20230368844
    Abstract: A method of operating a non-volatile semiconductor memory device is disclosed. The method comprises: during a first pre-read cycle of a read operation, ramping up a control signal on a wordline selected for the read operation to a first target pre-read voltage and ramping up a control signal on a drain-side select (SGD) transistor of an unselected string of the plurality of strings to a second target pre-read voltage. The method further comprises during a second pre-read cycle of the read operation, ramping down the control signal on the wordline to a target read voltage and ramping down the control signal on the SGD transistor of the unselected string to a third target pre-read voltage after a delay period after the triggering edge of the second pre-read cycle.
    Type: Application
    Filed: May 11, 2022
    Publication date: November 16, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Yanjie Wang, Guirong Liang
  • Publication number: 20230368846
    Abstract: Technology is disclosed herein for a memory system that compensates for different programming speeds in two sets of memory cells when reading those two sets of memory cells. The memory system programs a group of the memory cells to one or more data states. In one aspect, the memory cells are not verified during programming. The group has a first set of memory cells that program at a first speed and a second set of memory cells that program at a second speed. The memory system reads the first set of the memory cells with a first set of read parameters and reads the second set of the memory cells with a second set of read parameters. The first set of read parameters are different from the second set of read parameters to compensate for the different programming speeds.
    Type: Application
    Filed: May 10, 2022
    Publication date: November 16, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Jiacen Guo, Xiaochen Zhu, Xiang Yang, Lito De La Rama, Yi Song, Jiahui Yuan