Patents by Inventor Henry Chin

Henry Chin 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: 20190348129
    Abstract: A non-volatile memory system includes a control circuit connected to non-volatile memory cells. The control circuit is configured to simultaneously program memory cells connected to different word lines that are in different sub-blocks of different blocks in different planes of a die.
    Type: Application
    Filed: June 28, 2018
    Publication date: November 14, 2019
    Applicant: SANDISK TECHNOLOGIES LLC
    Inventors: Henry Chin, Zhenming Zhou
  • Publication number: 20190348127
    Abstract: A non-volatile memory system includes a control circuit connected to non-volatile memory cells. The control circuit is configured to simultaneously program memory cells connected to different word lines that are in different sub-blocks of different blocks in different planes of a die.
    Type: Application
    Filed: June 28, 2018
    Publication date: November 14, 2019
    Applicant: SANDISK TECHNOLOGIES LLC
    Inventors: Henry Chin, Zhenming Zhou
  • Publication number: 20190333581
    Abstract: Systems, methods, and devices of the various embodiments provide both “string-sharing” drain select gate electrodes and “string-selective” drain select gate electrodes in vertical NAND strings. Various embodiments may provide two or more vertical NAND strings sharing a common drain select gate electrode while also having separate additional drain select gate electrodes not electrically connected across the two or more vertical NAND strings.
    Type: Application
    Filed: June 21, 2018
    Publication date: October 31, 2019
    Inventors: Vinh DIEP, Ching Huang LU, Henry CHIN, Changyuan CHEN
  • Patent number: 10297330
    Abstract: Disturbs are reduced during programming and read operations for drain-side memory cells in a string by controlling dummy word line portions separately in selected and unselected sub-blocks. One or more of the dummy word line layers are separated so that they can be driven with different voltages. This allows the channel gradient to be optimized to reduce the likelihood of disturbs. In another aspect, a stack of alternating conductive and dielectric layers is formed in two parts, with lower pillars which comprise select gate transistors, source-side dummy memory cells and data memory cells, below upper pillars which comprise drain-side dummy memory cells and select gate transistors. The upper pillars are relatively narrow to provide a more compact structure. Moreover, the centerline of some upper pillars can be offset from the centerline of corresponding lower pillars to provide room for an isolation region.
    Type: Grant
    Filed: June 7, 2017
    Date of Patent: May 21, 2019
    Assignee: SanDisk Technologies LLC
    Inventors: Zhengyi Zhang, Henry Chin, Yingda Dong
  • Publication number: 20180358102
    Abstract: Disturbs are reduced during programming and read operations for drain-side memory cells in a string by controlling dummy word line portions separately in selected and unselected sub-blocks. One or more of the dummy word line layers are separated so that they can be driven with different voltages. This allows the channel gradient to be optimized to reduce the likelihood of disturbs. In another aspect, a stack of alternating conductive and dielectric layers is formed in two parts, with lower pillars which comprise select gate transistors, source-side dummy memory cells and data memory cells, below upper pillars which comprise drain-side dummy memory cells and select gate transistors. The upper pillars are relatively narrow to provide a more compact structure. Moreover, the centerline of some upper pillars can be offset from the centerline of corresponding lower pillars to provide room for an isolation region.
    Type: Application
    Filed: June 7, 2017
    Publication date: December 13, 2018
    Applicant: SanDisk Technologies LLC
    Inventors: Zhengyi Zhang, Henry Chin, Yingda Dong
  • Patent number: 10038005
    Abstract: Techniques are provided to boost current in channels of memory strings during sensing operations based on a data pattern or a pattern of physical non-uniformities, such as non-uniform channel widths. In one aspect, sense circuits are modified for memory strings which typically store meta data in a high programmed state. A bit line clamping transistor in these sense circuits can be configured with a relatively low threshold voltage, resulting in a relatively high clamping voltage which in turn causes a higher string current during sensing. The lower threshold voltage can be achieved by at least one of a shorter control gate length, a smaller oxide thickness, a lower oxide dielectric constant, or a greater source and/or drain doping concentration. In another aspect, memory strings which expected to typically store high state data are fabricated with a relatively thicker channel and/or greater doping concentration.
    Type: Grant
    Filed: June 12, 2017
    Date of Patent: July 31, 2018
    Assignee: SanDisk Technologies LLC
    Inventors: Zhengyi Zhang, Henry Chin, Yingda Dong
  • Patent number: 10025661
    Abstract: Technology is described herein for operating non-volatile storage. In one embodiment, the memory system tracks which adjustments to default values for hard bit read reference voltages are most frequently successful to decode data in non-volatile memory cells. In response to a process that uses only hard bits failing to successfully decode data in a group of the non-volatile memory cells, the memory system attempts to decode the data in the group of non-volatile memory cells using dynamic hard bit read reference voltages and dynamic soft bit read reference voltages that correspond to only a subset of the most frequently successful adjustments to the default values for the hard bit read reference voltages. By only using a subset of the most frequently successful adjustments to the default values for the hard bit read reference voltages time and power is saved.
    Type: Grant
    Filed: December 27, 2016
    Date of Patent: July 17, 2018
    Assignee: SanDisk Technologies LLC
    Inventors: Pitamber Shukla, Joanna Lai, Henry Chin, Deepak Raghu, Abhilash Kashyap
  • Publication number: 20180181462
    Abstract: Technology is described herein for operating non-volatile storage. In one embodiment, the memory system tracks which adjustments to default values for hard bit read reference voltages are most frequently successful to decode data in non-volatile memory cells. In response to a process that uses only hard bits failing to successfully decode data in a group of the non-volatile memory cells, the memory system attempts to decode the data in the group of non-volatile memory cells using dynamic hard bit read reference voltages and dynamic soft bit read reference voltages that correspond to only a subset of the most frequently successful adjustments to the default values for the hard bit read reference voltages. By only using a subset of the most frequently successful adjustments to the default values for the hard bit read reference voltages time and power is saved.
    Type: Application
    Filed: December 27, 2016
    Publication date: June 28, 2018
    Applicant: SanDisk Technologies LLC
    Inventors: Pitamber Shukla, Joanna Lai, Henry Chin, Deepak Raghu, Abhilash Kashyap
  • Publication number: 20180173447
    Abstract: Apparatuses, systems, methods, and computer program products are disclosed for dynamic read table generation. One apparatus includes a set of non-volatile storage cells. A controller for a set of non-volatile storage cells is configured to, in response to unsuccessfully reading a storage cell of the set of non-volatile storage cells using a parameter, read the storage cell using one or more shifted values. A controller for a set of non-volatile storage cells is configured to, in response to successfully reading a storage cell using one or more shifted values, add the one or more shifted values to a storage device.
    Type: Application
    Filed: December 16, 2016
    Publication date: June 21, 2018
    Applicant: SanDisk Technologies LLC
    Inventors: Henry Chin, Sateesh Desireddi, Dana Lee, Ashwin D T, Harshul Gupta, Parth Amin, Jia Li
  • Patent number: 9978456
    Abstract: Techniques are presented to reduce the amount of read disturb on partially written blocks of NAND type non-volatile memory, both for when determining the last written word line in a block and also for data read. In both cases, non-selected word lines that are unwritten or, in the case of finding the last written word line, may be unwritten are biased with a lower read-pass voltage then is typically used. The result of such reads can also be applied to an algorithm for finding the last written word by skipping a varying number of word lines. Performance in a last written page determination can also be improved by use of shorter bit line settling times than for a standard read.
    Type: Grant
    Filed: November 17, 2014
    Date of Patent: May 22, 2018
    Assignee: SanDisk Technologies LLC
    Inventors: Anubhav Khandelwal, Dana Lee, Abhijeet Manohar, Henry Chin, Gautam Dusija, Daniel Tuers, Chris Avila, Cynthia Hsu
  • Patent number: 9633738
    Abstract: A storage system includes a controller that is configured to make host data inaccessible. To do so, the controller may control power control circuitry to supply pulses to storage locations storing host data. The pulses may include flash write pulses but no erase pulses, or a combination of flash write pulses and erase pulses. If erase pulses are supplied, the number of the erase pulses may be less than the number supplied for performance of a default erase operation.
    Type: Grant
    Filed: June 28, 2016
    Date of Patent: April 25, 2017
    Assignee: SanDisk Technologies LLC
    Inventors: Zelei Guo, Pao-Ling Koh, Henry Chin, Pitamber Shukla, Deepak Raghu, Dana Lee
  • Patent number: 9620238
    Abstract: Non-volatile storage systems, and methods for programming non-volatile storage elements of non-volatile storage systems, are described herein. A method for programming a non-volatile storage element, wherein a loop number is incremented with each program-verify iteration includes performing a plurality of program-verify iterations for the non-volatile storage element. This includes inhibiting programming of the non-volatile storage element when the loop number is less than a loop number threshold corresponding to a target data state that the storage element is being programmed to. This also includes enabling programming of the non-volatile storage element when the the loop number is greater than or equal to the loop number threshold corresponding to the target data state that the storage element is being programmed to.
    Type: Grant
    Filed: September 22, 2014
    Date of Patent: April 11, 2017
    Assignee: SanDisk Technologies LLC
    Inventors: Anubhav Khandelwal, Dana Lee, Henry Chin, LanLan Gu
  • Patent number: 9552171
    Abstract: A number of complimentary techniques for the read scrub process using adaptive counter management are presented. In one set of techniques, in addition to maintaining a cumulative read counter for a block, a boundary word line counter can also be maintained to track the number of reads to most recently written word line or word lines of a partially written block. Another set of techniques used read count threshold values that vary with the number of program/erase cycles that a block has undergone. Further techniques involve setting the read count threshold for a closed (fully written) block based upon the number reads it experienced prior to being closed. These techniques can also be applied at a sub-block, zone level.
    Type: Grant
    Filed: October 29, 2014
    Date of Patent: January 24, 2017
    Assignee: SanDisk Technologies LLC
    Inventors: Yichao Huang, Chris Avila, Dana Lee, Henry Chin, Deepanshu Dutta, Sarath Puthenthermadam, Deepak Raghu
  • Patent number: 9552885
    Abstract: A non-volatile memory system mitigates the effects of open block reading by analyzing the un-programmed region of a block before programming to determine a potential for read disturbance. The system may determine a read count value associated with open block reading of the memory block and/or perform partial block erase verification. To mitigate the effects of open block read disturbance, the system performs partial block erase for the un-programmed region of the memory block and/or limits programming in the un-programmed region.
    Type: Grant
    Filed: July 8, 2015
    Date of Patent: January 24, 2017
    Assignee: SanDisk Technologies LLC
    Inventors: Pitamber Shukla, Henry Chin, Dana Lee, Cynthia Hsu
  • Patent number: 9548124
    Abstract: A memory device includes memory cells arranged in word lines. Due to variations in the fabrication process, with width and spacing between word lines can vary, resulting in widened threshold voltage distributions. In one approach, a programming parameter is optimized for each word line based on a measurement of the threshold voltage distributions in an initial programming operation. An adjustment to the programming parameter of a word line can be based, e.g., on measurements from adjacent word lines, and a position of the word line in a set of word lines. The programming parameter can include a programming mode such as a number of programming passes. Moreover, the programming parameters from one set of word lines can be used for another set of word lines having a similar physical layout due to the variations in the fabrication process.
    Type: Grant
    Filed: October 14, 2015
    Date of Patent: January 17, 2017
    Assignee: SanDisk Technologies LLC
    Inventors: Arash Hazeghi, Gerrit Jan Hemink, Dana Lee, Henry Chin, Bo Lei, Zhenming Zhou
  • Patent number: 9455038
    Abstract: A storage module and method are provided for using healing effects of a quarantine process. In one embodiment, a storage module is provided comprising a controller and a memory. The controller is configured to identify a set of memory cells in the memory that contains a bit error rate above a threshold, wherein the bit error rate is above the threshold due to trapped charge in dielectrics of the memory cells. The controller is also configured to quarantine the set of memory cells for a period of time, wherein while the set of memory cells is quarantined, heat generated by the storage module anneals the set of memory cells to at least partially remove the trapped charge.
    Type: Grant
    Filed: October 9, 2014
    Date of Patent: September 27, 2016
    Assignee: SanDisk Technologies LLC
    Inventors: Daniel E. Tuers, Dana Lee, Henry Chin, Abhijeet Manohar
  • Patent number: 9379120
    Abstract: High-density semiconductor memory utilizing metal control gate structures and air gap electrical isolation between discrete devices in these types of structures are provided. During gate formation and definition, etching the metal control gate layer(s) is separated from etching the charge storage layer to form protective sidewall spacers along the vertical sidewalls of the metal control gate layer(s). The sidewall spacers encapsulate the metal control gate layer(s) while etching the charge storage material to avoid contamination of the charge storage and tunnel dielectric materials. Electrical isolation is provided, at least in part, by air gaps that are formed in the row direction and/or air gaps that are formed in the column direction.
    Type: Grant
    Filed: July 22, 2013
    Date of Patent: June 28, 2016
    Assignee: SanDisk Technologies Inc.
    Inventors: Vinod Robert Purayath, Tuan Pham, Hiroyuki Kinoshita, Yuan Zhang, Henry Chin, James K Kai, Takashi W Orimoto, George Matamis, Henry Chien
  • Publication number: 20160172045
    Abstract: A non-volatile memory system mitigates the effects of open block reading by analyzing the un-programmed region of a block before programming to determine a potential for read disturbance. The system may determine a read count value associated with open block reading of the memory block and/or perform partial block erase verification. To mitigate the effects of open block read disturbance, the system performs partial block erase for the un-programmed region of the memory block and/or limits programming in the un-programmed region.
    Type: Application
    Filed: July 8, 2015
    Publication date: June 16, 2016
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: Pitamber Shukla, Henry Chin, Dana Lee, Cynthia Hsu
  • Patent number: 9361030
    Abstract: A memory system or flash card may be exposed to elapsed time or increased temperature conditions which may degrade the memory. For example, extended time periods or high temperature conditions may hinder data retention in a memory device. An estimate of elapsed time and temperature conditions may be useful for memory management. An algorithm that periodically identifies one or more sentinel blocks in the memory device and measures the data retention shift in those sentinel blocks can calculate a scalar value that approximates the combined effect of elapsed time and/or temperature conditions.
    Type: Grant
    Filed: October 9, 2014
    Date of Patent: June 7, 2016
    Assignee: SanDisk Technologies Inc.
    Inventors: Daniel E. Tuers, Dana Lee, Henry Chin, Abhijeet Manohar
  • Patent number: RE47226
    Abstract: A process is performed periodically or in response to an error in order to dynamically and adaptively optimize read compare levels based on memory cell threshold voltage distribution. One embodiment of the process includes determining threshold voltage distribution data for a population of non-volatile storage elements, smoothing the threshold voltage distribution data using a weighting function to create an interim set of data, determining a derivative of the interim set of data, and identifying and storing negative to positive zero crossings of the derivative as read compare points.
    Type: Grant
    Filed: March 31, 2014
    Date of Patent: February 5, 2019
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Nima Mokhlesi, Henry Chin