Patents by Inventor Alexander Kwok-Tung Mak

Alexander Kwok-Tung Mak 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: 9760307
    Abstract: An array of non-volatile memory cells includes a first plurality of nonvolatile memory cells and a second plurality of non-volatile memory cells. The first plurality of memory cells, which have first diameters of memory holes, are assigned to store portions of data that are not frequently read. The second plurality of memory cells, which have second diameters of memory holes, are assigned to store portions of data that are frequently read. The first diameters are smaller than the second diameters.
    Type: Grant
    Filed: September 22, 2015
    Date of Patent: September 12, 2017
    Assignee: SanDisk Technologies LLC
    Inventors: Chris Avila, Yingda Dong, Alexander Kwok-Tung Mak, Steven T. Sprouse
  • Publication number: 20160026410
    Abstract: In a nonvolatile memory array, such as a three-dimensional array of charge-storage memory cells, data is scrubbed according to a scheme which weights particular data that is exposed to potentially damaging voltages. Data that may cause damage to other data is moved to a location where such potential damage is reduced.
    Type: Application
    Filed: September 22, 2015
    Publication date: January 28, 2016
    Inventors: Chris Avila, Yingda Dong, Alexander Kwok-Tung Mak, Steven T. Sprouse
  • Patent number: 9240241
    Abstract: A 3D NAND stacked non-volatile memory device, comprising: a string comprising a plurality of non-volatile storage elements, the string comprises a channel and extends vertically through layers of the 3D stacked non-volatile memory device, and the plurality of storage elements are subdivided into different groups based on group assignments, each group of the different groups comprises multiple adjacent storage elements of the plurality of storage elements; and a control circuit in communication with the string, the control circuit, to perform a Pseudo Block Operation Mode.
    Type: Grant
    Filed: December 8, 2014
    Date of Patent: January 19, 2016
    Assignee: SanDisk Technologies Inc.
    Inventors: Xiying Costa, Alexander Kwok-Tung Mak, Chris Avila, Gautam Dusija, Man Mui
  • Patent number: 9230656
    Abstract: In a nonvolatile memory array in which a NAND string includes a back gate that has a charge storage element, the threshold voltage of the back gate is monitored, and if the threshold voltage deviates from a desired threshold voltage range, charge is added to, or removed from the charge storage element to return the threshold voltage to the desired threshold voltage range.
    Type: Grant
    Filed: June 26, 2013
    Date of Patent: January 5, 2016
    Assignee: SanDisk Technologies Inc.
    Inventors: Chris Nga Yee Avila, Gautam Ashok Dusija, Yingda Dong, Jian Chen, Man Lung Mui, Alexander Kwok-Tung Mak, Seungpil Lee
  • Patent number: 9218890
    Abstract: When data from a portion of a three dimensional NAND memory array is determined to be uncorrectable by Error Correction Code (ECC), a determination is made as to whether data is uncorrectable by ECC throughout some unit that is larger than the portion. If modified read conditions provide ECC correctable data, the modified read conditions are recorded for subsequent reads of the larger unit.
    Type: Grant
    Filed: June 3, 2013
    Date of Patent: December 22, 2015
    Assignee: SanDisk Technologies Inc.
    Inventors: Chris Nga Yee Avila, Gautam Ashok Dusija, Jian Chen, Yingda Dong, Man Lung Mui, Seungpil Lee, Alexander Kwok-Tung Mak
  • Patent number: 9183086
    Abstract: Portions of data stored in a three dimensional memory array are selected based on their locations for calculation of redundancy data. Locations are selected so that no two portions in a set of portions for a given calculation are likely to become uncorrectable at the same time. Selected portions may be separated by at least one word line and separated by at least one string in a block.
    Type: Grant
    Filed: June 3, 2013
    Date of Patent: November 10, 2015
    Assignee: SanDisk Technologies Inc.
    Inventors: Chris Nga Yee Avila, Gautam Ashok Dusija, Jian Chen, Yingda Dong, Man Lung Mui, Seungpil Lee, Alexander Kwok-Tung Mak
  • Patent number: 9171620
    Abstract: In a nonvolatile memory array, such as a three-dimensional array of charge-storage memory cells, data is scrubbed according to a scheme which weights particular data that is exposed to potentially damaging voltages. Data that may cause damage to other data is moved to a location where such potential damage is reduced.
    Type: Grant
    Filed: March 13, 2013
    Date of Patent: October 27, 2015
    Assignee: SanDisk Technologies Inc.
    Inventors: Chris Nga Yee Avila, Yingda Dong, Alexander Kwok-Tung Mak, Steven T. Sprouse
  • Patent number: 9070481
    Abstract: A method of operation in a non-volatile memory device, including executing a memory operation with respect to a portion of a non-volatile memory device, and measuring a current corresponding to current drawn by at least the portion of the non-volatile memory device during the memory operation. An age metric is determined for at least the portion of the non-volatile memory device based on age criteria including a characteristic of the measured current. In accordance with a determination that the age metric satisfies one or more predefined threshold criteria, one or more configuration parameters associated with the non-volatile memory device are adjusted. After the adjusting, data is read from and data to the portion of the non-volatile memory device according to the one or more adjusted configuration parameters.
    Type: Grant
    Filed: June 6, 2014
    Date of Patent: June 30, 2015
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Robert W. Ellis, James M. Higgins, Alexander Kwok-Tung Mak
  • Patent number: 9063671
    Abstract: Data that is stored in a higher error rate format in a nonvolatile memory is backed up in a lower error rate format. Data to be stored may be transferred once to on-chip data latches where it is maintained while it is programmed in both the high error rate format and the low error rate format without being resent to the nonvolatile memory. High error rate format may be MLC format and programming in the high error rate format may program both lower page and upper page data together in a full sequence programming scheme that is suitable for handling high data volume.
    Type: Grant
    Filed: July 2, 2013
    Date of Patent: June 23, 2015
    Assignee: SanDisk Technologies Inc.
    Inventors: Chris Nga Yee Avila, Gautam Ashok Dusija, Jian Chen, Alexander Kwok-Tung Mak, Seungpil Lee, Mrinal Kochar, Pao-Ling Koh
  • Patent number: 9058881
    Abstract: Multiple bits of data are programmed together to each cell of a segment of a word line while other segments of the same word line are unprogrammed. Subsequently, additional segments are similarly programmed. Data is read from a partially programmed word line (with a mix of programmed and unprogrammed segments) using a single reading scheme.
    Type: Grant
    Filed: December 5, 2013
    Date of Patent: June 16, 2015
    Assignee: SanDisk Technologies Inc.
    Inventors: Gautam A. Dusija, Chris Avila, Deepak Raghu, Yingda Dong, Man Mui, Alexander Kwok-Tung Mak, Pao-Ling Koh
  • Publication number: 20150162086
    Abstract: Multiple bits of data are programmed together to each cell of a segment of a word line while other segments of the same word line are unprogrammed. Subsequently, additional segments are similarly programmed. Data is read from a partially programmed word line (with a mix of programmed and unprogrammed segments) using a single reading scheme.
    Type: Application
    Filed: December 5, 2013
    Publication date: June 11, 2015
    Applicant: SanDisk Technologies Inc.
    Inventors: Gautam A. Dusija, Chris Avila, Deepak Raghu, Yingda Dong, Man Mui, Alexander Kwok-Tung Mak, Pao-Ling Koh
  • Publication number: 20150121156
    Abstract: Memory hole diameter in a three dimensional memory array may be calculated from characteristics that are observed during programming. Suitable operating parameters may be selected for operating a block based on memory hole diameters. Hot counts of blocks may be adjusted according to memory hole size so that blocks that are expected to fail earlier because of small memory holes are more lightly used than blocks with larger memory holes.
    Type: Application
    Filed: October 28, 2013
    Publication date: April 30, 2015
    Applicant: SanDisk Technologies Inc.
    Inventors: Deepak Raghu, Gautam A. Dusija, Chris Avila, Yingda Dong, Man Mui, Alexander Kwok-Tung Mak, Pao-Ling Koh
  • Publication number: 20150092493
    Abstract: A 3D NAND stacked non-volatile memory device, comprising: a string comprising a plurality of non-volatile storage elements, the string comprises a channel and extends vertically through layers of the 3D stacked non-volatile memory device, and the plurality of storage elements are subdivided into different groups based on group assignments, each group of the different groups comprises multiple adjacent storage elements of the plurality of storage elements; and a control circuit in communication with the string, the control circuit, to perform a Pseudo Block Operation Mode.
    Type: Application
    Filed: December 8, 2014
    Publication date: April 2, 2015
    Applicant: SanDisk Technologies Inc.
    Inventors: Xiying Costa, Alexander Kwok-Tung Mak, Chris Avila, Gautam Dusija, Man Mui
  • Patent number: 8964467
    Abstract: Multiple bits of data are programmed together to each cell of a segment of a word line while other segments of the same word line are unprogrammed. Subsequently, additional segments are similarly programmed. Data is read from a partially programmed word line (with a mix of programmed and unprogrammed segments) using a single reading scheme.
    Type: Grant
    Filed: May 22, 2014
    Date of Patent: February 24, 2015
    Assignee: SanDisk Technologies Inc.
    Inventors: Gautam A. Dusija, Chris Avila, Deepak Raghu, Yingda Dong, Man Mui, Alexander Kwok-Tung Mak, Pao-Ling Koh
  • Publication number: 20150012684
    Abstract: Data that is stored in a higher error rate format in a nonvolatile memory is backed up in a lower error rate format. Data to be stored may be transferred once to on-chip data latches where it is maintained while it is programmed in both the high error rate format and the low error rate format without being resent to the nonvolatile memory. High error rate format may be MLC format and programming in the high error rate format may program both lower page and upper page data together in a full sequence programming scheme that is suitable for handling high data volume.
    Type: Application
    Filed: July 2, 2013
    Publication date: January 8, 2015
    Inventors: Chris Nga Yee Avila, Gautam Ashok Dusija, Jian Chen, Alexander Kwok-Tung Mak, Seungpil Lee, Mrinal Kochar, Pao-Ling Koh
  • Publication number: 20150003161
    Abstract: In a nonvolatile memory array in which a NAND string includes a back gate that has a charge storage element, the threshold voltage of the back gate is monitored, and if the threshold voltage deviates from a desired threshold voltage range, charge is added to, or removed from the charge storage element to return the threshold voltage to the desired threshold voltage range.
    Type: Application
    Filed: June 26, 2013
    Publication date: January 1, 2015
    Applicant: SanDisk Technologies Inc.
    Inventors: Chris Nga Yee Avila, Gautam Ashok Dusija, Yingda Dong, Jian Chen, Man Lung Mui, Alexander Kwok-Tung Mak, Seungpil Lee
  • Patent number: 8924626
    Abstract: A method and system for phasing power-intensive operations is disclosed. A non-volatile storage device controller detects a power reset. The controller is in communication with non-volatile memories in the non-volatile storage device. In response to detecting a power reset, the controller determines a current consumption necessary to reset the non-volatile memories in the non-volatile storage device. The controller simultaneously resets all of the non-volatile memories when the determined current consumption is less than a current consumption threshold. If the determined current consumption is greater than the current consumption threshold, the controller resets a first subset of the plurality of non-volatile memories, and after a predetermined delay, resets a second subset of the non-volatile memories. Therefore, a power-intensive operation may be performed without exceeding a current consumption threshold by dividing the operation into a sequence of steps that do not exceed the threshold.
    Type: Grant
    Filed: April 29, 2010
    Date of Patent: December 30, 2014
    Assignee: SanDisk Technologies Inc.
    Inventors: Steven S. Cheng, Dennis Ea, Jianmin Huang, Alexander Kwok-Tung Mak, Farookh Moogat
  • Publication number: 20140369123
    Abstract: A 3D NAND stacked non-volatile memory device, comprising: a string comprising a plurality of non-volatile storage elements, the string comprises a channel and extends vertically through layers of the 3D stacked non-volatile memory device, and the plurality of storage elements are subdivided into different groups based on group assignments, each group of the different groups comprises multiple adjacent storage elements of the plurality of storage elements; and a control circuit in communication with the string, the control circuit, to perform a Pseudo Block Operation Mode.
    Type: Application
    Filed: May 9, 2014
    Publication date: December 18, 2014
    Applicant: SanDisk Technologies Inc.
    Inventors: Xiying Costa, Alexander Kwok-Tung Mak, Chris Avila, Gautam Dusija, Man Mui
  • Publication number: 20140369122
    Abstract: A 3D NAND stacked non-volatile memory device, comprising: a string comprising a plurality of non-volatile storage elements, the string comprises a channel and extends vertically through layers of the 3D stacked non-volatile memory device, and the plurality of storage elements are subdivided into different groups based on group assignments, each group of the different groups comprises multiple adjacent storage elements of the plurality of storage elements; and a control circuit in communication with the string, the control circuit, to perform a Pseudo Block Operation Mode.
    Type: Application
    Filed: January 10, 2014
    Publication date: December 18, 2014
    Applicant: SanDisk Technologies Inc.
    Inventors: Xiying Costa, Alexander Kwok-Tung Mak, Chris Avila, Gautam Dusija, Man Mui
  • Patent number: 8913431
    Abstract: A 3D NAND stacked non-volatile memory device, comprising: a string comprising a plurality of non-volatile storage elements, the string comprises a channel and extends vertically through layers of the 3D stacked non-volatile memory device, and the plurality of storage elements are subdivided into different groups based on group assignments, each group of the different groups comprises multiple adjacent storage elements of the plurality of storage elements; and a control circuit in communication with the string, the control circuit, to perform a Pseudo Block Operation Mode.
    Type: Grant
    Filed: May 9, 2014
    Date of Patent: December 16, 2014
    Assignee: SanDisk Technologies Inc.
    Inventors: Xiying Costa, Alexander Kwok-Tung Mak, Chris Avila, Gautam Dusija, Man Mui