Patents by Inventor Dengtao Zhao

Dengtao Zhao 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: 11062780
    Abstract: Method(s) and structure(s) for a two-page read operation are described and provide a multiple page read. The two page read operation provides for reading two pages with in a block without reducing the control gates to a low voltage level. The two page read can read the first page using an incrementing voltage level at discrete steps and starting the second page read at the high state for the control gates from the first page read. The second page read then decrements the control gate voltages level through the steps. This should reduce energy consumption. The two-page read operation will also reduce the time as the time period to reset the control gates to a low state are not required in between the page read operations.
    Type: Grant
    Filed: December 30, 2019
    Date of Patent: July 13, 2021
    Inventors: Zhiping Zhang, Huai-Yuan Tseng, Jiahui Yuan, Dengtao Zhao, Deepanshu Dutta
  • Publication number: 20210202011
    Abstract: Method(s) and structure(s) for a two-page read operation are described and provide a multiple page read. The two page read operation provides for reading two pages with in a block without reducing the control gates to a low voltage level. The two page read can read the first page using an incrementing voltage level at discrete steps and starting the second page read at the high state for the control gates from the first page read. The second page read then decrements the control gate voltages level through the steps. This should reduce energy consumption. The two-page read operation will also reduce the time as the time period to reset the control gates to a low state are not required in between the page read operations.
    Type: Application
    Filed: December 30, 2019
    Publication date: July 1, 2021
    Applicant: SanDisk Technologies LLC
    Inventors: Zhiping Zhang, Huai-Yuan Tseng, Jiahui Yuan, Dengtao Zhao, Deepanshu Dutta
  • Publication number: 20210159169
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, where the electrically conductive layers comprise word lines located between a source select gate electrode and a drain select gate electrode, a memory opening vertically extending through each layer of the alternating stack to a top surface of the substrate, a memory film and vertical semiconductor channel having a doping of a first conductivity type located in the memory opening, and an active region having a doping of a second conductivity type that is an opposite of the first conductivity type and adjoined to an end portion of the vertical semiconductor channel to provide a p-n junction. The end portion of the vertical semiconductor channel has a first thickness, and a middle portion of the vertical semiconductor channel has a second thickness which is less than the first thickness.
    Type: Application
    Filed: November 27, 2019
    Publication date: May 27, 2021
    Inventors: Dengtao ZHAO, Zhiping ZHANG, Peng ZHANG, Deepanshu DUTTA
  • Publication number: 20210134369
    Abstract: A method of concurrently programming a memory. Various methods include: applying a non-negative voltage on a first bit line coupled to a first memory cell; applying a negative voltage on a second bit line coupled to a second memory cell, where the negative voltage is generated using triple-well technology; then applying a programming pulse to the first and second memory cells concurrently; and in response, programming the first and second memory cells to different states. The methods also include applying a quick pass write operation to the first and second memory cells, by: applying a quick pass write voltage to the first bit line coupled to the fist memory cell, where the quick pass write voltage is higher than the non-negative voltage; applying a negative quick pass write voltage to the second bit line coupled to the first memory cell, where the negative quick pass write voltage is generated using triple-well technology.
    Type: Application
    Filed: October 30, 2019
    Publication date: May 6, 2021
    Applicant: SanDisk Technologies LLC
    Inventors: Zhiping Zhang, Muhammad Masuduzzaman, Huai-Yuan Tseng, Dengtao Zhao, Deepanshu Dutta
  • Publication number: 20210134372
    Abstract: A method reading memory using bi-directional sensing, including programming first memory cells coupled to a first word-line using a normal programming order; programming second memory cells coupled to a second word-line using a normal programming order; reading data from the first memory cells by applying a normal sensing operation to the first word-line; and reading data from the second memory cells by applying a reverse sensing operation to the second word-line. Methods also include receiving an error associated with reading data from the first memory cells; and then reading the data from the first memory cells by applying a reverse sensing operation to the first word-line. Method also include receiving an error associated with reading the data from the second memory cells; and then reading the data from the second memory cells by applying a normal sensing operation to the second word-line.
    Type: Application
    Filed: November 6, 2019
    Publication date: May 6, 2021
    Applicant: SanDisk Technologies LLC
    Inventors: Zhiping Zhang, Muhammad Masuduzzaman, Huai-Yuan Tseng, Peng Zhang, Dengtao Zhao, Deepanshu Dutta
  • Publication number: 20210134370
    Abstract: A method of concurrently programming a memory. Various methods include: applying a non-negative voltage on a first bit line coupled to a first memory cell; applying a negative voltage on a second bit line coupled to a second memory cell, where the negative voltage is generated using triple-well technology; then applying a programming pulse to the first and second memory cells concurrently; and in response, programming the first and second memory cells to different states. The methods also include applying a quick pass write operation to the first and second memory cells, by: applying a quick pass write voltage to the first bit line coupled to the first memory cell, where the quick pass write voltage is higher than the non-negative voltage; applying a negative quick pass write voltage to the second bit line coupled to the first memory cell, where the negative quick pass write voltage is generated using triple-well technology.
    Type: Application
    Filed: December 3, 2019
    Publication date: May 6, 2021
    Applicant: SanDisk Technologies LLC
    Inventors: Zhiping Zhang, Muhammad Masuduzzaman, Huai-Yuan Tseng, Dengtao Zhao, Deepanshu Dutta
  • Patent number: 10832785
    Abstract: Program disturb is a condition that includes the unintended programming of a memory cell while performing a programming process for other memory cells. Such unintended programming can cause an error in the data being stored. In some cases, program disturb can result from electrons trapped in the channel being accelerated from one side of a selected word line to another side of the selected word line and redirected into the selected word line. To prevent such program disturb, it is proposed to open the channel from one side of a selected word line to the other side of the selected word line after a sensing operation for program verify and prior to a subsequent programming voltage being applied.
    Type: Grant
    Filed: April 3, 2020
    Date of Patent: November 10, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Dengtao Zhao, Peng Zhang, Nan Lu, Deepanshu Dutta
  • Patent number: 10825513
    Abstract: A memory system includes a sense system configured to control parasitic noise sources by increasing selected bit line or channel voltages during sense stages. The increase may be tied to a triggering threshold voltage level. That is, while performing a memory operation, the sense system may increase the selected bit line voltage level dependent on a reference voltage level or memory state associated with a sense stage being above the triggering threshold level.
    Type: Grant
    Filed: June 26, 2018
    Date of Patent: November 3, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Dengtao Zhao, Deepanshu Dutta, Zhenming Zhou
  • Publication number: 20200258558
    Abstract: An apparatus includes a plurality of NAND strings in a block with word lines connected to cells of the NAND strings and select lines connected to select gate transistors of the NAND strings. A control circuit is configured to, after a read operation of memory cells of the block apply substantially zero volts to the global word lines to discharge the word lines to substantially zero volts. The control circuit is further configured to turn off the select gate transistors to isolate channels, turn off the block select transistors to isolate the word lines from the global word lines, and with the block select transistors turned off, apply a low positive voltage on the global word lines.
    Type: Application
    Filed: May 17, 2019
    Publication date: August 13, 2020
    Applicant: Western Digital Technologies, Inc.
    Inventors: Abhijith Prakash, Anubhav Khandelwal, Deepanshu Dutta, Huai-Yuan Tseng, Wei Zhao, Dengtao Zhao
  • Patent number: 10734070
    Abstract: Non-volatile memory strings may include multiple selection devices for coupling memory cell devices to a bit line. Different programming operations may be used to program various individual selection devices in a non-volatile memory cells string. For example, a control circuit may set a threshold voltage of a particular selection device to a value greater than a threshold voltage of another selection device. In another example, the control circuit may program the selection device using an initial sense time. Subsequent to programming the selection device using the initial sense time, the control circuit may program the selection device using a different sense time that is shorter than the initial sense time.
    Type: Grant
    Filed: June 26, 2018
    Date of Patent: August 4, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Xiang Yang, Dengtao Zhao, Huai-Yuan Tseng, Deepanshu Dutta, Zhongguang Xu, Yanli Zhang, Jin Liu
  • Patent number: 10726891
    Abstract: An apparatus includes a plurality of NAND strings in a block with word lines connected to cells of the NAND strings and select lines connected to select gate transistors of the NAND strings. A control circuit is configured to, after a read operation of memory cells of the block apply substantially zero volts to the global word lines to discharge the word lines to substantially zero volts. The control circuit is further configured to turn off the select gate transistors to isolate channels, turn off the block select transistors to isolate the word lines from the global word lines, and with the block select transistors turned off, apply a low positive voltage on the global word lines.
    Type: Grant
    Filed: May 17, 2019
    Date of Patent: July 28, 2020
    Assignee: Western Digital Technologies, Inc.
    Inventors: Abhijith Prakash, Anubhav Khandelwal, Deepanshu Dutta, Huai-Yuan Tseng, Wei Zhao, Dengtao Zhao
  • Publication number: 20200234778
    Abstract: Program disturb is a condition that includes the unintended programming of a memory cell while performing a programming process for other memory cells. Such unintended programming can cause an error in the data being stored. In some cases, program disturb can result from electrons trapped in the channel being accelerated from one side of a selected word line to another side of the selected word line and redirected into the selected word line. To prevent such program disturb, it is proposed to open the channel from one side of a selected word line to the other side of the selected word line after a sensing operation for program verify and prior to a subsequent programming voltage being applied.
    Type: Application
    Filed: April 3, 2020
    Publication date: July 23, 2020
    Applicant: SANDISK TECHNOLOGIES LLC
    Inventors: Dengtao Zhao, Peng Zhang, Nan Lu, Deepanshu Dutta
  • Patent number: 10643718
    Abstract: Program disturb is a condition that includes the unintended programming of a memory cell while performing a programming process for other memory cells. Such unintended programming can cause an error in the data being stored. In some cases, program disturb can result from electrons trapped in the channel being accelerated from one side of a selected word line to another side of the selected word line and redirected into the selected word line. To prevent such program disturb, it is proposed to open the channel from one side of a selected word line to the other side of the selected word line after a sensing operation for program verify and prior to a subsequent programming voltage being applied.
    Type: Grant
    Filed: June 7, 2018
    Date of Patent: May 5, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Dengtao Zhao, Peng Zhang, Nan Lu, Deepanshu Dutta
  • Patent number: 10580504
    Abstract: Program disturb is a condition that includes the unintended programming of a memory cell while performing a programming process for other memory cells. Such unintended programming can cause an error in the data being stored. In some cases, program disturb can result from electrons trapped in the channel being accelerated from one side of a selected word line to another side of the selected word line and redirected into the selected word line. To prevent such program disturb, it is proposed to open the channel from one side of a selected word line to the other side of the selected word line after a sensing operation for program verify and prior to a subsequent programming voltage being applied.
    Type: Grant
    Filed: June 7, 2018
    Date of Patent: March 3, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Dengtao Zhao, Peng Zhang, Nan Lu, Deepanshu Dutta
  • Patent number: 10553298
    Abstract: Program disturb is a condition that includes the unintended programming while performing a programming process for other memory cells. Such unintended programming can cause an error in the data being stored. In some cases, program disturb can result from electrons trapped in the channel being accelerated from one side of a dummy word line to another side of the dummy word line and redirected into a select gate. To prevent such program disturb, it is proposed to open the channel from one side of the dummy word line to the other side of the dummy word line after a sensing operation for program verify and prior to a subsequent programming voltage being applied. For example, the channel can be opened up by applying a voltage to the dummy word line prior to pre-charging unselected memory cells.
    Type: Grant
    Filed: July 27, 2018
    Date of Patent: February 4, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Dengtao Zhao, Deepanshu Dutta
  • Publication number: 20200035312
    Abstract: Program disturb is a condition that includes the unintended programming while performing a programming process for other memory cells. Such unintended programming can cause an error in the data being stored. In some cases, program disturb can result from electrons trapped in the channel being accelerated from one side of a dummy word line to another side of the dummy word line and redirected into a select gate. To prevent such program disturb, it is proposed to open the channel from one side of the dummy word line to the other side of the dummy word line after a sensing operation for program verify and prior to a subsequent programming voltage being applied. For example, the channel can be opened up by applying a voltage to the dummy word line prior to pre-charging unselected memory cells.
    Type: Application
    Filed: July 27, 2018
    Publication date: January 30, 2020
    Applicant: SANDISK TECHNOLOGIES LLC
    Inventors: Dengtao Zhao, Deepanshu Dutta
  • Patent number: 10541037
    Abstract: Program disturb is a condition that includes the unintended programming of a memory cell while performing a programming process for other memory cells. Such unintended programming can cause an error in the data being stored. In some cases, program disturb can result from electrons trapped in the channel being accelerated from one side of a selected word line to another side of the selected word line and redirected into the selected word line. To prevent such program disturb, it is proposed to open the channel from one side of a selected word line to the other side of the selected word line after a sensing operation for program verify and prior to a subsequent programming voltage being applied.
    Type: Grant
    Filed: June 7, 2018
    Date of Patent: January 21, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Dengtao Zhao, Deepanshu Dutta
  • Publication number: 20190392894
    Abstract: A memory system includes a sense system configured to control parasitic noise sources by increasing selected bit line or channel voltages during sense stages. The increase may be tied to a triggering threshold voltage level. That is, while performing a memory operation, the sense system may increase the selected bit line voltage level dependent on a reference voltage level or memory state associated with a sense stage being above the triggering threshold level.
    Type: Application
    Filed: June 26, 2018
    Publication date: December 26, 2019
    Applicant: SanDisk Technologies LLC
    Inventors: Dengtao Zhao, Deepanshu Dutta, Zhenming Zhou
  • Publication number: 20190392893
    Abstract: Non-volatile memory strings may include multiple selection devices for coupling memory cell devices to a bit line. Different programming operations may be used to program various individual selection devices in a non-volatile memory cells string. For example, a control circuit may set a threshold voltage of a particular selection device to a value greater than a threshold voltage of another selection device. In another example, the control circuit may program the selection device using an initial sense time. Subsequent to programming the selection device using the initial sense time, the control circuit may program the selection device using a different sense time that is shorter than the initial sense time.
    Type: Application
    Filed: June 26, 2018
    Publication date: December 26, 2019
    Inventors: Xiang Yang, Dengtao Zhao, Huai-Yuan Tseng, Deepanshu Dutta, Zhongguang Xu, Yanli Zhang, Jin Liu
  • Publication number: 20190378579
    Abstract: Program disturb is a condition that includes the unintended programming of a memory cell while performing a programming process for other memory cells. Such unintended programming can cause an error in the data being stored. In some cases, program disturb can result from electrons trapped in the channel being accelerated from one side of a selected word line to another side of the selected word line and redirected into the selected word line. To prevent such program disturb, it is proposed to open the channel from one side of a selected word line to the other side of the selected word line after a sensing operation for program verify and prior to a subsequent programming voltage being applied.
    Type: Application
    Filed: June 7, 2018
    Publication date: December 12, 2019
    Applicant: SANDISK TECHNOLOGIES LLC
    Inventors: Dengtao Zhao, Deepanshu Dutta