Patents by Inventor Muhammad Masuduzzaman

Muhammad Masuduzzaman 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: 20240078028
    Abstract: Technology is disclosed herein for managing timing parameters when programming memory cells. Timing parameters used sub-clocks in an MLC program mode may also be used for those same sub-clocks in a first SLC program mode. However, in a second SLC program mode a different set of timing parameters may be used for that set of sub-clocks. Using the same set of timing parameters for the MLC program mode and the first SLC program mode saves storage space. However, the timing parameters for the MLC program mode may be slower than desired for SLC programming. A different set of timing parameters may be used for the second SLC program mode to provide for faster program operation. Moreover, the different set of timing parameters used for the faster SLC program mode do not require storage of a separate set of timing parameters.
    Type: Application
    Filed: September 1, 2022
    Publication date: March 7, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Chin-Yi Chen, Muhammad Masuduzzaman, Xiang Yang
  • Publication number: 20240071524
    Abstract: Technology is disclosed herein for smart verify in a memory system that has a four bit per cell program mode (or X4 mode) and also a three bit per cell program mode (or X3 mode). The X3 mode uses a three-bit gray code that is based on a four-bit gray code of the X4 mode. The memory system skips verify of states in the X3 mode, while using a considerable portion of the programming logic from the X4 mode. In one X3 mode the memory system skips B-state verify while the number of memory cells having a Vt above an A-state verify voltage is below a threshold. In one X3 mode the memory system determines whether to skip verify for a first set of data states based on a first test and determines whether to skip verify for a second set of data states based on a second test.
    Type: Application
    Filed: August 25, 2022
    Publication date: February 29, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Xiang Yang, Henry Chin, Erika Penzo, Muhammad Masuduzzaman
  • Patent number: 11887677
    Abstract: The memory device includes a controller that is configured to program the memory cells of a selected word line in a plurality of program-verify iterations. During a verify portion at least one of the program-verify iterations, the controller determines a threshold voltage of at least one memory cell relative to a first verify low voltage VL1, a second verify low voltage VL2, and a verify high voltage VH associated with a data state being programmed. The controller also maintains a count of program-verify iterations since the at least one memory cell passed a verify high voltage of a previously programmed data state or discharges a sense node through a channel including the at least one memory cell and compares a discharge time to predetermined sense times associated with the first and second verify low voltages and with the verify high voltage.
    Type: Grant
    Filed: March 22, 2022
    Date of Patent: January 30, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Muhammad Masuduzzaman, Deepanshu Dutta, Gerrit Jan Hemink
  • 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: 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: 11830555
    Abstract: A storage device is provided that performs constant biasing in priority blocks, such as OTP memory blocks (fuse ROM) and flash memory blocks having a threshold number of P/E cycles. The storage device includes an OTP memory, a flash memory, and a controller. The OTP memory includes a block having a word line and a plurality of cells coupled to the word line. The flash memory includes another block having a word line and a plurality of cells coupled to this word line. The controller is configured to apply a constant bias to the word line of the OTP memory block and, in some cases to the word line of the flash memory block, between execution of host commands. As a result, lower bit error rates due to wider Vt margins may occur while system power may be saved through selective application of constant biasing.
    Type: Grant
    Filed: June 25, 2021
    Date of Patent: November 28, 2023
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Muhammad Masuduzzaman, Deepanshu Dutta
  • 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: 11776634
    Abstract: A storage device is provided that applies pulsed biasing during power-up or read recovery. The storage device includes a memory and a controller. The memory includes a block having a word line and cells coupled to the word line. The controller applies a voltage pulse to the word line during power-up or in response to a read error. The voltage pulse may include an amplitude and a pulse width that are each a function of a number of P/E cycles of the block. The controller may also perform pulsed biasing during both power-up and read recovery by applying one or more first voltage pulses to the word line during power-up and one or more second voltage pulses to the word line in response to a read error. As a result, lower bit error rates due to wider Vt margins may occur and system power may be saved over constant biasing.
    Type: Grant
    Filed: June 25, 2021
    Date of Patent: October 3, 2023
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Muhammad Masuduzzaman, Deepanshu Dutta
  • Publication number: 20230307072
    Abstract: The memory device includes a controller that is configured to program the memory cells of a selected word line in a plurality of program-verify iterations. During a verify portion at least one of the program-verify iterations, the controller determines a threshold voltage of at least one memory cell relative to a first verify low voltage VL1, a second verify low voltage VL2, and a verify high voltage VH associated with a data state being programmed. The controller also maintains a count of program-verify iterations since the at least one memory cell passed a verify high voltage of a previously programmed data state or discharges a sense node through a channel including the at least one memory cell and compares a discharge time to predetermined sense times associated with the first and second verify low voltages and with the verify high voltage.
    Type: Application
    Filed: March 22, 2022
    Publication date: September 28, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Muhammad Masuduzzaman, Deepanshu Dutta, Gerrit Jan Hemink
  • Patent number: 11574693
    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 corresponding to one of a plurality of memory states. A control circuit is coupled to the plurality of word lines and strings and is configured to erase the memory cells using a stripe erase operation in response to determining a cycle count is less than a predetermined cycle count maximum threshold. The control circuit is also configured to perform a dummy cycle operation in response to determining the cycle count is not less than the predetermined cycle count maximum threshold.
    Type: Grant
    Filed: June 15, 2021
    Date of Patent: February 7, 2023
    Assignee: SanDisk Technologies LLC
    Inventors: Chin-Yi Chen, Muhammad Masuduzzaman, Dengtao Zhao, Anubhav Khandelwal, Ravi Kumar
  • Publication number: 20220415402
    Abstract: A storage device is provided that performs constant biasing in priority blocks, such as OTP memory blocks (fuse ROM) and flash memory blocks having a threshold number of P/E cycles. The storage device includes an OTP memory, a flash memory, and a controller. The OTP memory includes a block having a word line and a plurality of cells coupled to the word line. The flash memory includes another block having a word line and a plurality of cells coupled to this word line. The controller is configured to apply a constant bias to the word line of the OTP memory block and, in some cases to the word line of the flash memory block, between execution of host commands. As a result, lower bit error rates due to wider Vt margins may occur while system power may be saved through selective application of constant biasing.
    Type: Application
    Filed: June 25, 2021
    Publication date: December 29, 2022
    Inventors: Muhammad MASUDUZZAMAN, Deepanshu Dutta
  • Publication number: 20220415406
    Abstract: A storage device is provided that applies pulsed biasing during power-up or read recovery. The storage device includes a memory and a controller. The memory includes a block having a word line and cells coupled to the word line. The controller applies a voltage pulse to the word line during power-up or in response to a read error. The voltage pulse may include an amplitude and a pulse width that are each a function of a number of PIE cycles of the block. The controller may also perform pulsed biasing during both power-up and read recovery by applying one or more first voltage pulses to the word line during power-up and one or more second voltage pulses to the word line in response to a read error. As a result, lower bit error rates due to wider Vt margins may occur and system power may be saved over constant biasing.
    Type: Application
    Filed: June 25, 2021
    Publication date: December 29, 2022
    Inventors: Muhammad MASUDUZZAMAN, Deepanshu Dutta
  • Publication number: 20220413761
    Abstract: A storage device is provided that conditionally performs read refresh in blocks having higher P/E cycles or older programming times, while refraining from performing read refreshes in blocks having lower P/E cycles or recent programming times. The storage device includes a memory and a controller. The memory includes a block having cells. The controller performs a read refresh on the cells when a number of P/E cycles of the block exceeds an age threshold or after a threshold amount time has elapsed since data was programmed in the block. The controller may also refrain from performing read refreshes on the cells until the number of P/E cycles exceeds the age threshold or until a threshold amount of time has elapsed since the data is programmed. As a result, lower BER may occur due to wider Vt margins, while power and system overhead may be saved.
    Type: Application
    Filed: June 25, 2021
    Publication date: December 29, 2022
    Inventors: Muhammad MASUDUZZAMAN, Deepanshu Dutta, Abhijith Prakash
  • Publication number: 20220399066
    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 corresponding to one of a plurality of memory states. A control circuit is coupled to the plurality of word lines and strings and is configured to erase the memory cells using a stripe erase operation in response to determining a cycle count is less than a predetermined cycle count maximum threshold. The control circuit is also configured to perform a dummy cycle operation in response to determining the cycle count is not less than the predetermined cycle count maximum threshold.
    Type: Application
    Filed: June 15, 2021
    Publication date: December 15, 2022
    Applicant: SanDisk Technologies LLC
    Inventors: Chin-Yi Chen, Muhammad Masuduzzaman, Dengtao Zhao, Anubhav Khandelwal, Ravi Kumar
  • Publication number: 20220359024
    Abstract: The non-volatile memory includes a control circuitry that is communicatively coupled to an array of memory cells that are arranged word lines. The control circuitry is configured to program the memory cells using a multi-pass programming operation which includes a first pass and a second pass. The first pass programs the memory cells to a first number of data states, and the second pass programs the memory cells to a greater second number of data states. For at least one word line, during the second pass, a voltage that is applied to at least one memory cell is reduced from a verify voltage by an offset which is determined as a function of a data state of an adjacent memory cell of an adjacent word line and wherein the first pass but not the second pass has been completed in the adjacent word line.
    Type: Application
    Filed: May 4, 2021
    Publication date: November 10, 2022
    Applicant: SanDisk Technologies LLC
    Inventors: Xue Pitner, Muhammad Masuduzzaman, Ravi Kumar
  • Patent number: 11475967
    Abstract: The non-volatile memory includes a control circuitry that is communicatively coupled to an array of memory cells that are arranged word lines. The control circuitry is configured to program the memory cells using a multi-pass programming operation which includes a first pass and a second pass. The first pass programs the memory cells to a first number of data states, and the second pass programs the memory cells to a greater second number of data states. For at least one word line, during the second pass, a voltage that is applied to at least one memory cell is reduced from a verify voltage by an offset which is determined as a function of a data state of an adjacent memory cell of an adjacent word line and wherein the first pass but not the second pass has been completed in the adjacent word line.
    Type: Grant
    Filed: May 4, 2021
    Date of Patent: October 18, 2022
    Assignee: SanDisk Technologies LLC
    Inventors: Xue Pitner, Muhammad Masuduzzaman, Ravi Kumar
  • Patent number: 11423993
    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: Grant
    Filed: November 6, 2019
    Date of Patent: August 23, 2022
    Assignee: SanDisk Technologies LLC
    Inventors: Zhiping Zhang, Muhammad Masuduzzaman, Huai-Yuan Tseng, Peng Zhang, Dengtao Zhao, Deepanshu Dutta
  • Patent number: 11417393
    Abstract: A method for programming a non-volatile memory structure with four-page data, wherein the method comprises, in a first stage, selecting four programmable states of a segment of MLC NAND-type memory cells, programming at least a first of the four programmable states with two pages of a four-page data at a first step voltage level, between programming at least two neighboring programmable states of the four programmable states, increasing the first step voltage level to a second step voltage level for a single program pulse and according to a pre-determined magnitude, and programming a latter of the at least two neighboring programmable states at the first step voltage level.
    Type: Grant
    Filed: January 6, 2021
    Date of Patent: August 16, 2022
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Sujjatul Islam, Muhammad Masuduzzaman, Ravi Kumar
  • Publication number: 20220215873
    Abstract: A method for programming a non-volatile memory structure with four-page data, wherein the method comprises, in a first stage, selecting four programmable states of a segment of MLC NAND-type memory cells, programming at least a first of the four programmable states with two pages of a four-page data at a first step voltage level, between programming at least two neighboring programmable states of the four programmable states, increasing the first step voltage level to a second step voltage level for a single program pulse and according to a pre-determined magnitude, and programming a latter of the at least two neighboring programmable states at the first step voltage level.
    Type: Application
    Filed: January 6, 2021
    Publication date: July 7, 2022
    Applicant: SanDisk Technologies LLC
    Inventors: Sujjatul Islam, Muhammad Masuduzzaman, Ravi Kumar
  • Patent number: 11322213
    Abstract: A method comprises determining a verify voltage for a next iteration of a verify operation to be performed on memory cells a first set of memory cells of a selected word line, and determining data states for a second set of memory cells of at least one neighboring word line. The method further comprises determining, based on the data states, a verify voltage configuration that includes bit line voltage biases or sense times, and performing the next iteration of the verify operation on the selected word line by using the verify voltage configuration to iteratively verify whether respective memory cells, of the second set of memory cells, have threshold voltages above the verify voltage, wherein determining the data states, determining the verify voltage configuration, and performing the next iteration are to be repeated until a program stop condition is satisfied.
    Type: Grant
    Filed: June 12, 2020
    Date of Patent: May 3, 2022
    Assignee: SanDisk Technologies LLC
    Inventors: Muhammad Masuduzzaman, Deepanshu Dutta