Patents by Inventor Xiang Yang

Xiang Yang has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • 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: 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
  • Patent number: 11881266
    Abstract: A memory apparatus and method of operation are provided. The memory apparatus includes memory cells connected to word lines and disposed in memory holes organized in rows grouped in strings. The memory cells are configured to retain a threshold voltage. The rows include full circle rows and semi-circle rows in which the memory holes are partially cut by a slit half etch. The memory holes of the semi-circle rows are coupled semi-circle bit lines and the memory holes of the full circle rows are coupled to full circle bit lines. A control means is configured to erase the memory cells in an erase operation. During the erase operation, the control means creates a capacitive coupling between each of the semi-circle bit lines and at least one neighboring one of the full circle bit lines to increase a semi-circle erase voltage applied to each of the semi-circle bit lines.
    Type: Grant
    Filed: February 8, 2022
    Date of Patent: January 23, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Xiang Yang, Kou Tei, Ohwon Kwon
  • 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
  • Patent number: 11871580
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, an array of memory opening fill structures located within an array of memory openings vertically extending through the alternating stack, and a drain-select-level isolation structure vertically extending through drain-select-level electrically conductive layers between two rows of memory opening fill structures. The drain-select-level isolation structure may comprise a low-k dielectric material or an air gap.
    Type: Grant
    Filed: May 11, 2021
    Date of Patent: January 9, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Peng Zhang, Yanli Zhang, Xiang Yang, Koichi Matsuno, Masaaki Higashitani, Johann Alsmeier
  • Patent number: 11862249
    Abstract: In order to inhibit memory cells from programming and mitigate program disturb, the memory pre-charges channels of NAND strings connected to a common set of control lines by applying positive voltages to the control lines and applying voltages to a source line and bit lines connected to the NAND strings. The control lines include word lines and select lines. The word lines include an edge word line. The memory ramps down the positive voltages applied to the control lines, including ramping down control lines on a first side of the edge word line, ramping down the edge word line, and performing a staggered ramp down of three or more control lines on a second side of the edge word line. After the pre-charging, unselected NAND strings have their channel boosted to prevent programming and selected NAND strings experience programming on selected memory cells.
    Type: Grant
    Filed: November 16, 2021
    Date of Patent: January 2, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Xiang Yang, Fanqi Wu, Jiacen Guo, Jiahui Yuan
  • Publication number: 20230409230
    Abstract: Memory die management based on biasing voltages. Some memory dies are formed of memory holes having a semi-circular shape. This semi-circular shape results in a decrease in biasing voltage compared to memory holes having a circular shape. Systems and methods described herein organize memory dies into memory die groups according to their biasing voltages. During operation, data is relocated between the memory die groups based on how often the data is read. Data may be scrambled within their respective memory die groups to maintain appropriate storage space.
    Type: Application
    Filed: May 17, 2022
    Publication date: December 21, 2023
    Inventors: Abhijith Prakash, Xiang Yang
  • Publication number: 20230410906
    Abstract: An apparatus includes a control circuit configured to connect to memory cells connected in series in NAND strings. Each NAND string includes a plurality of data memory cells coupled to a plurality of data word lines in series with a plurality of dummy memory cells connected to a plurality of dummy word lines. The control circuit configured to apply a first dummy word line voltage to one or more dummy word lines of the plurality of dummy word lines in a verify step of a program operation to program data memory cells. The control circuit is configured to apply a second dummy word line voltage to the one or more dummy word lines in a read operation to read the data memory cells.
    Type: Application
    Filed: May 25, 2022
    Publication date: December 21, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Yi Song, Jiahui Yuan, Xiang Yang
  • Publication number: 20230410921
    Abstract: An apparatus is provided that includes a plurality of memory cells, logic circuits coupled to the memory cells and configured to store 4-bit data in each of the memory cells, and a control circuit coupled to the memory cells and the logic circuits. The control circuit configured to cause the logic circuits to store 3-bit data in each of the memory cells.
    Type: Application
    Filed: June 21, 2022
    Publication date: December 21, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Xiang Yang, Deepanshu Dutta, Jiacen Guo, Takayuki Inoue, Hua-Ling Hsu
  • Publication number: 20230410912
    Abstract: A memory apparatus and method of operation are provided. The apparatus includes drain-side select gate transistors for coupling to a drain-side of each of a plurality of memory holes of memory cells and configured to retain a transistor threshold voltage. The memory apparatus also includes a control means coupled to the drain-side select gate transistor of each of the plurality of memory holes. The control means is configured to select the transistor threshold voltage of the drain-side select gate transistors as a stable transistor threshold voltage for a grouping of the memory cells to minimize shifting of the transistor threshold voltage following a plurality of read operations of the memory cells. The control means is also configured to program the transistor threshold voltage of the drain-side select gate transistor of the plurality of memory holes associated with the grouping of the memory cells to the stable transistor threshold voltage.
    Type: Application
    Filed: June 15, 2022
    Publication date: December 21, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Abhijith Prakash, Xiang Yang
  • Publication number: 20230410922
    Abstract: A memory apparatus and method of operation are provided. The apparatus includes memory cells each connected to word lines. The memory cells are disposed in strings and 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 targeted for each of the memory cells during a program-verify portion of a program operation. The control means is also configured to trim the program verify voltages for each of the data states for a grouping of the memory cells based on quantities of the memory cells having the threshold voltage crossing over between the data states in crossovers in a verify level trimming process.
    Type: Application
    Filed: June 15, 2022
    Publication date: December 21, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Abhijith Prakash, Xiang Yang
  • Patent number: 11848059
    Abstract: A method of erasing memory cells in a memory device is provided. The method includes grouping a plurality of word lines into a first group, which does not include edge word lines, and a second group, which does include edge word lines. An erase operation is performed on the memory cells of the first and second groups until erase-verify of the memory cells of the first group passes. It is then determined if further erase of the memory cells of the second group is necessary. In response to it being determined that the additional erase operation is necessary, an additional erase operation is performed on at least some of the memory cells of the second group until erase-verify of the memory cells of the second group passes.
    Type: Grant
    Filed: November 18, 2021
    Date of Patent: December 19, 2023
    Assignee: SanDisk Technologies LLC
    Inventors: Jiacen Guo, Xiang Yang, Abhijith Prakash
  • Publication number: 20230402105
    Abstract: The memory device includes a memory block with a plurality of memory cells, which are programmed to multiple bits per memory cell, arranged in a plurality of word lines. Control circuitry is provided and is configured to read the memory cells of a selected word line. The control circuitry separates the memory cells of the selected word line into a first group of memory cells, which are located on a side of the word line are near a voltage driver, and a second group of memory cells, which are located on an opposite side of the word line from the voltage driver. The control circuitry reads the memory cells of the first group using a first read mode and reads the memory cells of the second group using a second read mode that is different than the first read mode to reduce a fail bit count during read.
    Type: Application
    Filed: June 10, 2022
    Publication date: December 14, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Jiacen Guo, Xiang Yang
  • Patent number: 11840927
    Abstract: A method may include determining, during a first time step within an iterative simulation process, various pseudo-pressure values based on model data. The method may include determining, during the first time step, a first set of skin factor values for the wellbore radial grid portions using the pseudo-pressure values. The method may include simulating, during the first time step, a first well production rate for a well within a reservoir region of interest using the first set of skin factor values and a first pressure distribution for the reservoir region of interest. The method may include simulating, during a second time step within the iterative simulation process, a second well production rate for the well using a second set of skin factor values and a second pressure distribution for the reservoir region of interest.
    Type: Grant
    Filed: September 18, 2020
    Date of Patent: December 12, 2023
    Assignee: SAUDI ARABIAN OIL COMPANY
    Inventors: Ali Haydar Dogru, Xiang Yang Ding
  • Patent number: 11837297
    Abstract: A method for dynamically adjusting an erase voltage level to be applied in a subsequent erase cycle, comprising: in a current erase cycle, initiating a current erase/verify loop by applying an initial stored erase voltage level according to an erase sequence in which each successive erase/verify loop is incremented by a pre-determined voltage amount, storing an erase/verify loop count, and determining whether the current erase cycle is complete according to a pass criterion. If the erase cycle is complete, a determination is made as to whether the stored erase/verify loop count equals a pre-defined threshold count. Further, if the stored count does not equal the pre-defined threshold count, the initial stored erase voltage level is adjusted such that, upon applying the adjusted erase voltage level in a subsequent erase cycle, an erase/verify loop count will now equal the pre-defined threshold count.
    Type: Grant
    Filed: June 10, 2021
    Date of Patent: December 5, 2023
    Assignee: SanDisk Technologies LLC
    Inventor: Xiang Yang
  • Patent number: 11837292
    Abstract: A memory apparatus and method of operation are provided. The memory apparatus includes memory cells connected to word lines and disposed in memory holes. The memory cells are connected in series between a drain-side select gate transistor on a drain-side and connected to one of a plurality of bit lines and a source line on a source-side. A control means is configured to apply a first and a second select gate voltage to the drain-side select gate transistor while applying a predetermined source line voltage to the source line of selected ones of the memory holes in a predetermined grouping and a read level voltage to at least one of the word lines associated with the predetermined grouping. The control means counts the memory cells conducting during each of a first and a second read operation and adjusts the predetermined source line voltage accordingly.
    Type: Grant
    Filed: December 23, 2021
    Date of Patent: December 5, 2023
    Assignee: San Disk Technologies LLC
    Inventors: Jiacen Guo, Xiang Yang
  • 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: 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: 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
  • 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