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).

  • 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: 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
  • Publication number: 20230343400
    Abstract: A memory apparatus and method of operation are provided. The apparatus includes memory cells connected to word lines and disposed in strings. A control means is coupled to the word lines and the strings and is configured to ramp a voltage applied to a selected one of the word lines from a verify voltage to a reduced voltage during a program-verify portion of a program operation. The control means successively ramps voltages applied to each of a plurality of neighboring ones of the word lines from a read pass voltage to the reduced voltage beginning with ones of the plurality of neighboring ones of the word lines immediately adjacent the selected one of the word lines and progressing to ones of the plurality of neighboring others of the word lines disposed increasingly remotely from the selected one of the word lines during the program-verify portion of the program operation.
    Type: Application
    Filed: April 20, 2022
    Publication date: October 26, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Jiacen Guo, Xiang Yang, Abhijith Prakash
  • Patent number: 11798625
    Abstract: An apparatus includes a control circuit configured to connect to first word lines of a first vertical sub-block and second word lines of a second vertical sub-block. The first vertical sub-block and the second vertical sub-block include memory cells connected in series in NAND strings, each NAND string including memory cells coupled to the first word lines in series with memory cells connected to the second word lines. The control circuit is configured to program or sense memory cells along a selected first word line of the first vertical sub-block while applying a first voltage to second word lines that are connected to programmed memory cells and applying a second voltage to second word lines that are connected to unprogrammed memory cells.
    Type: Grant
    Filed: September 8, 2021
    Date of Patent: October 24, 2023
    Assignee: SanDisk Technologies LLC
    Inventors: Xiang Yang, Deepanshu Dutta, Gerrit Jan Hemink
  • Patent number: 11798638
    Abstract: Technology for mitigating interference to select transistors in 3D memory is disclosed. In one aspect, a control circuit pre-charges a first set of bit lines to a first voltage and pre-charges a second set of bit lines to a second voltage greater than the first voltage. The control circuit may increase the voltage on the first set of bit lines to the second voltage while the second set of bit lines are floating to couple up the voltages on the second set of bit lines to a voltage greater than the second voltage. The higher voltage on the second set of bit lines compensates for interference that some of the select transistors may experience from an adjacent select line. For example, the higher voltage can prevent a leakage current in the select transistors from occurring. Preventing the leakage current can improve boosting of NAND channel voltages, thereby preventing program disturb.
    Type: Grant
    Filed: September 24, 2021
    Date of Patent: October 24, 2023
    Assignee: SanDisk Technologies LLC
    Inventors: Xiang Yang, Kou Tei, Ohwon Kwon
  • Publication number: 20230326530
    Abstract: A memory apparatus and method of operation is provided. The apparatus includes memory cells connected to word lines. The memory cells are disposed in memory holes and grouped into a plurality of tiers. The memory cells are configured to retain a threshold voltage corresponding to one of a plurality of data states to store one bit as single-level cells and a plurality of bits as multi-level cells. The apparatus also includes a control means coupled to the word lines and the memory holes and configured to select a predetermined strobe quantity of the plurality of tiers of the memory cells separately for the memory cells operating as the single-level cells and the memory cells operating as the multi-level cells. The control means is also configured to trigger sensing of the predetermined strobe quantity of the plurality of tiers of the memory cells during a verify operation.
    Type: Application
    Filed: April 7, 2022
    Publication date: October 12, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Chin-Yi Chen, Muhammad Masuduzzaman, Kou Tei, Deepanshu Dutta, Hiroyuki Mizukoshi, Jiahui Yuan, Xiang Yang
  • Patent number: 11783903
    Abstract: A memory apparatus and method of operation are provided. The apparatus includes memory cells connected to one of a plurality of word lines and arranged in strings and configured to retain a threshold voltage. A control means is coupled to the plurality of word lines and the strings. The control means is configured to apply a primary predetermined voltage to a primary location of the memory apparatus following an erase operation of the memory cells while simultaneously applying a secondary predetermined voltage being lower than the primary predetermined voltage to a secondary location of the memory apparatus and measuring a leak current at the primary location. The control means then determines the erase operation passed in response to the leak current measured not being greater than a predetermined leak threshold.
    Type: Grant
    Filed: October 27, 2021
    Date of Patent: October 10, 2023
    Assignee: SanDisk Technologies LLC
    Inventors: Xiang Yang, Xiaochen Zhu
  • Patent number: 11776628
    Abstract: The following disclosure is directed to mitigating issues related to semi-circle drain side select gate (SC-SGD) memory holes in memory structures. When a memory hole is cut, the channel and the charge trap layer of the memory hole cut. Further, the outer dielectric layer (used to shield the channel and the charge trap layer) is cut and partially removed. When the selected SC-SGD is selected for an operation (e.g., programming), the channel and the charge trap layer are exposed to neighboring electrical field from bias voltage applied to an unselected SC-SGD. To prevent or mitigate the effects of this electrical field, a negative bias voltage is applied to the unselected SC-SGD. Additionally, this disclosure is directed to self-compensating techniques for SC-SGD. For example, the memory structure can utilize the neighboring electric field during verify, program, and read operations, whether the neighboring electric field is relatively strong or weak.
    Type: Grant
    Filed: June 17, 2021
    Date of Patent: October 3, 2023
    Assignee: SanDisk Technologies LLC
    Inventors: Xiang Yang, Kazuki Isozumi, Parth Amin
  • Patent number: 11776643
    Abstract: Non-volatile memory systems and method for managing P/E cycling is disclosed. Memory systems include multi-plane (e.g., 2-plane or 4-plane) programming operations in which new blocks within a plane replace faulty/bad blocks. Existing blocks, having undergone several P/E cycles more than the new block(s), require a lower programming voltage and are programmed using an adaptive (reduced) programming voltage. New block(s) require an additional voltage, and a delta voltage is added to the programming voltage to increase the gate-to-channel voltage. To prevent the delta voltage from over-programming the existing blocks, a voltage equal to the delta voltage is applied bit lines of the existing blocks, thereby reducing the effective gate-to-channel voltage on the existing blocks.
    Type: Grant
    Filed: June 3, 2021
    Date of Patent: October 3, 2023
    Assignee: SanDisk Technologies LLC
    Inventor: Xiang Yang
  • Publication number: 20230304042
    Abstract: This disclosure provides replication-incompetent adenoviral vectors useful in vaccine development and gene therapy. The disclosed vectors comprise a selective deletion of E3 and are particularly useful for preparation of vaccines development and for gene therapy using toxic transgene products that result in vector instability that occurs when the entire E3 domain is deleted.
    Type: Application
    Filed: May 31, 2023
    Publication date: September 28, 2023
    Inventors: Hildegund C.J. Ertl, Xiang Yang Zhou
  • Publication number: 20230307070
    Abstract: A memory apparatus and method of operation are provided. The apparatus includes memory cells connected to word lines and disposed in memory holes organized in rows grouped in strings and configured to retain a threshold voltage. The memory cells are connected in series between a drain-side select gate transistor on a drain-side of each of the memory holes and a source-side select gate transistor on a source-side of each of the memory holes. A control means determines whether a downshift recovery trigger event has occurred in memory operations. In response to determining the downshift recovery trigger event has occurred, the control means inserts at least one of a predetermined idle time in the memory operations and a recovery pulse of a negative voltage to the drain-side select gate transistor of the memory holes of the strings for a predetermined pulse period of time during one of the memory operations.
    Type: Application
    Filed: February 8, 2022
    Publication date: September 28, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Abhijith Prakash, Xiang Yang
  • Publication number: 20230298667
    Abstract: An apparatus is provided that includes a word line coupled to a word line driver circuit, bit lines, a plurality of non-volatile memory cells each coupled to the word line and a corresponding one of the bit lines, and a control circuit coupled to the word line and the bit lines. The control circuit is configured to program the memory cells by causing the word line driver to apply a program pulse to the word line, and biasing each bit line to a corresponding bit line voltage that has a value that varies based on a distance between the word line driver and the corresponding bit line.
    Type: Application
    Filed: March 17, 2022
    Publication date: September 21, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Jiacen Guo, Xiang Yang, Xiaochen Zhu
  • Publication number: 20230290419
    Abstract: The memory device includes a plurality of memory cells which are arranged in an array. The memory device further includes a plurality of bit lines that are coupled with the memory cells and a controller. The controller is configured to program the memory cells from an erased data state to three programmed data states in a programming operation that includes three programming pulses and zero verify operations using different patterns to dictate the application of inhibit voltages to the bit lines during each of the three programming pulses. The patterns include two pre-established patterns and additional patterns that are derived from the pre-established patterns using logic operations.
    Type: Application
    Filed: March 9, 2022
    Publication date: September 14, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Xiang Yang, Takayuki Inoue, Jiacen Guo
  • Publication number: 20230282288
    Abstract: The memory device includes a chip with circuitry, a plurality of memory blocks, and a plurality of bit lines. The memory blocks include an array of memory cells, and the circuitry either overlies or underlies the array of memory cells. The bit lines are divided into two portions that are electrically connected with one another via at least one transistor so that at least one portion of each bit line can be charged independently of the other portion of the same bit line. During some read operations, this allows the memory device to operate with lower power requirements.
    Type: Application
    Filed: March 3, 2022
    Publication date: September 7, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Xiang Yang, Deepanshu Dutta, Ohwon Kwon, James Kai, Yuki Mizutani
  • Publication number: 20230253053
    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: Application
    Filed: February 8, 2022
    Publication date: August 10, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Xiang Yang, Kou Tei, Ohwon Kwon
  • Publication number: 20230253056
    Abstract: A memory apparatus and method of operation are provided. The apparatus includes memory cells connected to word lines including a dummy word line and other data word lines. The memory cells are disposed in memory holes and configured to retain a threshold voltage. A control means is coupled to the word lines and the memory holes and is configured to determine whether one of the word lines being programmed in a program operation is a particular one of the word lines adjacent the dummy word line needing a dummy positioning operation. The control means is also configured to program the memory cells connected to the dummy word line to adjust the threshold voltage to a predetermined position threshold voltage in the dummy positioning operation in response to determining the one of the plurality of word lines being programmed in the program operation is the particular one of the word lines.
    Type: Application
    Filed: February 4, 2022
    Publication date: August 10, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Xiang Yang, Abhijith Prakash
  • Publication number: 20230238062
    Abstract: The memory device includes a block with a plurality of memory cells arranged in a plurality of data word lines, which are arranged in sub-blocks that are not separated from one another by physical joints or by dummy word lines. A controller is configured to erase the memory cells of a selected sub-block of the plurality of sub-blocks without erasing the memory cells of the unselected sub-blocks. The controller reads data of the edge one word lines of the unselected sub-blocks adjacent the selected sub-block and stores this data in a temporary location external of the block before erasing the memory cells of the selected sub-block. The controller then re-programs the data that is being temporarily stored back into the memory cells of the edge word lines of the unselected sub-blocks after erase of the selected sub-block is completed.
    Type: Application
    Filed: January 25, 2022
    Publication date: July 27, 2023
    Applicant: SanDisk Technologies LLC
    Inventor: Xiang Yang
  • Patent number: 11702675
    Abstract: This disclosure provides replication-incompetent adenoviral vectors useful in vaccine development and gene therapy. The disclosed vectors comprise a selective deletion of E3 and are particularly useful for preparation of vaccines development and for gene therapy using toxic transgene products that result in vector instability that occurs when the entire E3 domain is deleted.
    Type: Grant
    Filed: September 30, 2020
    Date of Patent: July 18, 2023
    Assignee: The Wistar Institute
    Inventors: Hildegund C. J. Ertl, Xiang Yang Zhou
  • Patent number: 11699495
    Abstract: A method for programming a memory block of a non-volatile memory structure, comprising determining whether a number of programming/erase cycles previously applied to the block exceeds a first programming/erase cycle threshold and, if the first threshold is exceeded, determining whether the number of programming/erase cycles previously applied to the block exceeds an extended programming/erase cycle threshold. Further, if the determination is made that the extended threshold is not exceeded, the method comprises applying a two-pulse per programming loop scheme to each of the outermost strings of the block and applying a single-pulse per programming loop scheme to all other strings of the block. Alternatively, or in addition thereto, relative to a programming/erase cycle threshold, one or more outermost strings of the block may be unpermitted to be further programmed, and a “sub-block” comprised of all valid strings of the block may be defined and permitted for further programming.
    Type: Grant
    Filed: June 16, 2021
    Date of Patent: July 11, 2023
    Assignee: SanDisk Technologies LLC
    Inventor: Xiang Yang
  • Publication number: 20230207021
    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: Application
    Filed: December 23, 2021
    Publication date: June 29, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Jiacen Guo, Xiang Yang