Patents by Inventor Yingda Dong

Yingda Dong 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: 10650898
    Abstract: An apparatus having an erase controller configured to perform a two-sided gate-induced drain leakage (GIDL) erase of non-volatile memory cells is disclosed. The erase controller is configured to apply a first voltage pulse having a first value for a voltage pulse attribute to the first end of a first pathway. The erase controller is configured to apply a second voltage pulse having a second value for the voltage pulse attribute to the first end of a second pathway. The first value and the second value are configured to compensate for different impedances such that a first erase voltage at a first select transistor is substantially symmetric with a second erase voltage at a second select transistor.
    Type: Grant
    Filed: November 6, 2018
    Date of Patent: May 12, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Peter Rabkin, Kwang-Ho Kim, Masaaki Higashitani, Yingda Dong
  • Publication number: 20200143889
    Abstract: An apparatus comprising an impedance compensation circuit is disclosed. The impedance compensation circuit compensates for impedance differences between a first pathway connected to a first transistor and a second pathway connected to a second transistor. However, rather than making a compensation based on a signal (e.g., voltage) applied to either the first or the second pathway, a compensation is made based on the signals (e.g., voltage pulses) applied to third and fourth pathways connected to the transistors.
    Type: Application
    Filed: December 27, 2018
    Publication date: May 7, 2020
    Applicant: SanDisk Technologies LLC
    Inventors: Peter Rabkin, Kwang-Ho Kim, Masaaki Higashitani, Yingda Dong
  • Publication number: 20200143888
    Abstract: An apparatus having an erase controller configured to perform a two-sided gate-induced drain leakage (GIDL) erase of non-volatile memory cells is disclosed. The erase controller is configured to apply a first voltage pulse having a first value for a voltage pulse attribute to the first end of a first pathway. The erase controller is configured to apply a second voltage pulse having a second value for the voltage pulse attribute to the first end of a second pathway. The first value and the second value are configured to compensate for different impedances such that a first erase voltage at a first select transistor is substantially symmetric with a second erase voltage at a second select transistor.
    Type: Application
    Filed: November 6, 2018
    Publication date: May 7, 2020
    Applicant: SanDisk Technologies LLC
    Inventors: Peter Rabkin, Kwang-Ho Kim, Masaaki Higashitani, Yingda Dong
  • Patent number: 10636488
    Abstract: Methods and systems for improving the reliability of stored data in the presence of cross-temperature variation are described. To reduce the number of data errors caused by cross-temperature variation, two or more sensing passes may be performed corresponding with two or more different sensing times. The amount of shifting in the memory cell threshold voltages may be determined on a per-bit basis or on a cell-by-cell basis based on the sensing operations performed during the two or more sensing passes. The stored data states may be assigned based on the amount of shifting in the memory cell threshold voltages during the two or more sensing passes and the type of cross-temperature variation present (e.g., whether the memory cells were programmed at a temperature above 65 degrees Celsius and read back at a temperature below 25 degrees Celsius).
    Type: Grant
    Filed: September 24, 2018
    Date of Patent: April 28, 2020
    Assignee: Western Digital Technologies, Inc.
    Inventors: Lei Lin, Wei Zhao, Henry Chin, Yingda Dong
  • Patent number: 10636500
    Abstract: Techniques for reducing read disturb of memory cells in a two-tier stack having a lower tier and an upper tier separated by an interface. In a read operation, the channels of NAND strings are discharged before reading the selected memory cells. The discharge involves ramping up the word line voltages and grounding the ends of the NAND strings. To increase the discharge, a ramp up rate may be greater for the selected word line and for dummy memory cells adjacent to the interface, compared to the ramp up rate for the unselected word lines. In an option, the greater ramp up rate is also used for the word lines between the selected word line and the interface. In another option, the greater ramp up rate is used for the word lines in the same tier as the selected word line.
    Type: Grant
    Filed: December 20, 2018
    Date of Patent: April 28, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Hong-Yan Chen, Wei Zhao, Yingda Dong
  • Publication number: 20200075631
    Abstract: A memory element is provided that includes a portion of a bit line plug, a portion of a source line plug, a portion of a word line, a portion of a vertical semiconductor pillar disposed between the bit line plug, the source line plug and adjacent the word line, and a gate oxide including a ferroelectric material disposed between the vertical semiconductor pillar and the word line.
    Type: Application
    Filed: September 3, 2019
    Publication date: March 5, 2020
    Applicant: SANDISK TECHNOLOGIES LLC
    Inventors: Yingda Dong, James Kai, Christopher J. Petti
  • Patent number: 10559588
    Abstract: A three-dimensional memory device includes alternating stacks of insulating strips and electrically conductive strips laterally spaced apart among one another by line trenches and a two-dimensional array of memory stack structures and a two-dimensional array of dielectric pillar structures located in the line trenches. Each line trench is filled with laterally alternating sequence of memory stack structures and dielectric pillar structures. Each memory stack structure contains a vertical semiconductor channel, a pair of blocking dielectrics contacting outer sidewalls of the vertical semiconductor channel, a pair of charge storage layers contacting outer sidewalls of the pair of blocking dielectrics, and a pair of tunneling dielectrics contacting outer sidewalls of the pair of charge storage layers.
    Type: Grant
    Filed: May 4, 2018
    Date of Patent: February 11, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Yingda Dong, Yangyin Chen, James Kai
  • Patent number: 10541035
    Abstract: Apparatuses and techniques are provided for accurately reading memory cells by compensating for lateral charge diffusion between adjacent memory cells. A selected memory cell is read with a compensation which is based on classifying the threshold voltages of adjacent memory cells into bins. In one aspect, the compensation is based on the level of the current control gate voltage of the selected word line. In another aspect, the classifying of the threshold voltages of the adjacent memory cells can be a function of temperature. In another aspect, a memory cell can be read with compensation after a previous read operation without compensation results in an uncorrectable error. In another aspect, the classifying uses more bins for a selected edge word line.
    Type: Grant
    Filed: June 28, 2018
    Date of Patent: January 21, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Ching-Huang Lu, Han-Ping Chen, Chung-Yao Pai, Yingda Dong
  • Publication number: 20200020704
    Abstract: A non-volatile memory system is provided that includes a plurality of NAND strings of non-volatile storage elements, each non-volatile storage element including a control gate, a tunneling layer, a floating gate, and a blocking layer including a ferroelectric material. The tunneling layer is disposed between the control gate and the floating gate, and the floating gate is disposed between the tunneling layer and the blocking layer.
    Type: Application
    Filed: September 24, 2019
    Publication date: January 16, 2020
    Applicant: SanDisk Technologies LLC
    Inventors: Yingda Dong, Yangyin Chen, Yukihiro Sakotsubo
  • Publication number: 20200005878
    Abstract: Apparatuses and techniques are provided for accurately reading memory cells by compensating for lateral charge diffusion between adjacent memory cells. A selected memory cell is read with a compensation which is based on classifying the threshold voltages of adjacent memory cells into bins. In one aspect, the compensation is based on the level of the current control gate voltage of the selected word line. In another aspect, the classifying of the threshold voltages of the adjacent memory cells can be a function of temperature. In another aspect, a memory cell can be read with compensation after a previous read operation without compensation results in an uncorrectable error. In another aspect, the classifying uses more bins for a selected edge word line.
    Type: Application
    Filed: June 28, 2018
    Publication date: January 2, 2020
    Applicant: SanDisk Technologies LLC
    Inventors: Ching-Huang Lu, Han-Ping Chen, Chung-Yao Pai, Yingda Dong
  • Publication number: 20200006375
    Abstract: A three-dimensional memory device includes alternating stacks of insulating strips and electrically conductive strips located over a substrate and laterally spaced apart among one another by line trenches. The line trenches laterally extend along a first horizontal direction and are spaced apart along a second horizontal direction. Each line trench fill structure includes a laterally undulating dielectric rail having a laterally undulating width along the second horizontal direction and extending along the first horizontal direction and a row of memory stack structures located at neck regions of the laterally undulating dielectric rail.
    Type: Application
    Filed: June 27, 2018
    Publication date: January 2, 2020
    Inventors: Fei Zhou, Yingda Dong, Raghuveer S. Makala
  • Patent number: 10522232
    Abstract: Apparatuses and techniques are described for reducing an injection type of program disturb in a memory device. A voltage on a selected word line is increased in a first step from an initial level such as 0 V to an intermediate, pass level such as Vpass, and in a second step from Vpass to a peak program level of Vpgm. A voltage on an adjacent unselected word line can be increased from the initial level to Vpass and then temporarily increased to an elevated level of Vpass_el during the second step increase on the selected word line. This helps reduce the magnitude of a channel gradient between the selected word line and the adjacent word line. The increase to Vpass_el may be implemented for program loops in the later part of a program operation, when Vpgm and the risk of program disturb is relatively high.
    Type: Grant
    Filed: May 18, 2018
    Date of Patent: December 31, 2019
    Assignee: SanDisk Technologies LLC
    Inventors: Hong-Yan Chen, Yingda Dong
  • Publication number: 20190371402
    Abstract: Methods and systems for improving the reliability of stored data in the presence of cross-temperature variation are described. To reduce the number of data errors caused by cross-temperature variation, two or more sensing passes may be performed corresponding with two or more different sensing times. The amount of shifting in the memory cell threshold voltages may be determined on a per-bit basis or on a cell-by-cell basis based on the sensing operations performed during the two or more sensing passes. The stored data states may be assigned based on the amount of shifting in the memory cell threshold voltages during the two or more sensing passes and the type of cross-temperature variation present (e.g., whether the memory cells were programmed at a temperature above 65 degrees Celsius and read back at a temperature below 25 degrees Celsius).
    Type: Application
    Filed: September 24, 2018
    Publication date: December 5, 2019
    Applicant: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Lei Lin, Wei Zhao, Henry Chin, Yingda Dong
  • Patent number: 10497711
    Abstract: A three-dimensional non-volatile memory is provided with reduced programming variation across word lines. The gate lengths of word lines decrease from the top to the bottom of the memory hole. Increased programming speeds due to a narrow memory hole are offset by a smaller gate length at corresponding positions. A blocking dielectric thickness may also be varied, independently or in combination with a variable word line thickness. The blocking dielectric is formed with a horizontal thickness that is larger at regions adjacent to the lower word line layers and smaller at regions adjacent to the upper word line layers. The larger thickness at the lower word line layers reduces the programming speed in the memory hole for the lower word lines relative to the upper word lines. A variance in programming speed resulting from differences in memory hole diameter may be offset by a corresponding variance in blocking dielectric thickness.
    Type: Grant
    Filed: December 19, 2017
    Date of Patent: December 3, 2019
    Assignee: SanDisk Technologies LLC
    Inventors: Ashish Baraskar, Liang Pang, Yanli Zhang, Raghuveer Makala, Yingda Dong
  • Publication number: 20190355429
    Abstract: Apparatuses and techniques are described for reducing an injection type of program disturb in a memory device. A voltage on a selected word line is increased in a first step from an initial level such as 0 V to an intermediate, pass level such as Vpass, and in a second step from Vpass to a peak program level of Vpgm. A voltage on an adjacent unselected word line can be increased from the initial level to Vpass and then temporarily increased to an elevated level of Vpass_el during the second step increase on the selected word line. This helps reduce the magnitude of a channel gradient between the selected word line and the adjacent word line. The increase to Vpass_el may be implemented for program loops in the later part of a program operation, when Vpgm and the risk of program disturb is relatively high.
    Type: Application
    Filed: May 18, 2018
    Publication date: November 21, 2019
    Applicant: SanDisk Technologies LLC
    Inventors: Hong-Yan Chen, Yingda Dong
  • Patent number: 10461095
    Abstract: A non-volatile storage element is provided that includes a control gate, a blocking layer including a ferroelectric material, a charge storage region, and a tunneling layer. The blocking layer is disposed between the control gate and the charge storage region, and the charge storage region is disposed between the tunneling layer and the blocking layer.
    Type: Grant
    Filed: March 28, 2018
    Date of Patent: October 29, 2019
    Assignee: SanDisk Technologies LLC
    Inventors: Yingda Dong, Yangyin Chen, Yukihiro Sakotsubo
  • Patent number: 10453862
    Abstract: A memory cell is provided that includes a control gate, a tunneling layer, a charge storage region, a blocking layer including a ferroelectric material, a semiconductor channel, and a source region and a drain region each disposed adjacent the semiconductor channel. The tunneling layer is disposed between the control gate and the charge storage region, the charge storage region is disposed between the tunneling layer and the blocking layer, and the blocking layer is disposed above the semiconductor channel.
    Type: Grant
    Filed: March 28, 2018
    Date of Patent: October 22, 2019
    Assignee: SanDisk Technologies LLC
    Inventors: Yingda Dong, Yangyin Chen, Yukihiro Sakotsubo
  • Patent number: 10453861
    Abstract: A non-volatile storage element including a control gate, a tunneling layer, a charge storage region, and a blocking layer including a ferroelectric material. The tunneling layer is disposed between the control gate and the charge storage region, and the charge storage region is disposed between the tunneling layer and the blocking layer.
    Type: Grant
    Filed: March 28, 2018
    Date of Patent: October 22, 2019
    Assignee: SanDisk Technologies LLC
    Inventors: Yingda Dong, Yangyin Chen, Yukihiro Sakotsubo
  • Patent number: 10446244
    Abstract: Apparatuses and techniques are described for programming memory cells with a narrow threshold voltage (Vth) distribution in a memory device. In one approach, the final pass of a multi-pass program operation on a word line WLn includes applying a variable voltage to WLn+1 during verify tests on WLn. The variable voltage (Vread) can be an increasing function of the verify voltage on WLn, and thus a function of the data state for which the verify test is performed. In one approach, Vread on WLn+1 is stepped up with each increase in the verify voltage on WLn. The step size in Vread can be the same as, or different than, the step size in the verify voltage. Vread can be different for each different verify voltage, or multiple verify voltages can be grouped for use with a common Vread.
    Type: Grant
    Filed: April 9, 2018
    Date of Patent: October 15, 2019
    Assignee: SanDisk Technologies LLC
    Inventors: Vinh Diep, Ching-Huang Lu, Zhengyi Zhang, Yingda Dong
  • Publication number: 20190311772
    Abstract: Apparatuses and techniques are described for programming memory cells with a narrow threshold voltage (Vth) distribution in a memory device. In one approach, the final pass of a multi-pass program operation on a word line WLn includes applying a variable voltage to WLn+1 during verify tests on WLn. The variable voltage (Vread) can be an increasing function of the verify voltage on WLn, and thus a function of the data state for which the verify test is performed. In one approach, Vread on WLn+1 is stepped up with each increase in the verify voltage on WLn. The step size in Vread can be the same as, or different than, the step size in the verify voltage. Vread can be different for each different verify voltage, or multiple verify voltages can be grouped for use with a common Vread.
    Type: Application
    Filed: April 9, 2018
    Publication date: October 10, 2019
    Applicant: SanDisk Technologies LLC
    Inventors: Vinh Diep, Ching-Huang Lu, Zhengyi Zhang, Yingda Dong