Patents by Inventor Dana Lee

Dana Lee 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: 20170090822
    Abstract: A device includes a memory device and a controller. The controller is coupled to the memory device. The controller is configured to, in response to receiving a request to perform a memory access at the memory device, determine that the memory device has a characteristic indicative of a temperature crossing. The controller is also configured to, in response to the determination, increase a temperature of the memory device by performing memory operations on the memory device until detecting a condition related to the temperature.
    Type: Application
    Filed: March 4, 2016
    Publication date: March 30, 2017
    Inventors: Preeti Yadav, Prasanna Desai Sudhir Rao, Smita Aggarwal, Dana Lee
  • Publication number: 20170091015
    Abstract: A device includes a memory device and a controller. The memory device includes read/write circuitry and a plurality of memory dies. The controller is coupled to the memory device. The controller is configured to, responsive to determining that at least one storage element of a first die of the plurality of memory dies has a characteristic indicative of an aging condition, increase the temperature of the first die by performing memory operations on the first die until detecting a condition related to the temperature.
    Type: Application
    Filed: September 28, 2015
    Publication date: March 30, 2017
    Inventors: PREETI YADAV, PRASANNA DESAI SUDHIR RAO, SMITA AGGARWAL, DANA LEE
  • Publication number: 20170032846
    Abstract: A split gate NAND flash memory structure is formed on a semiconductor substrate of a first conductivity type. The NAND structure comprises a first region of a second conductivity type in the substrate with a second region of the second conductivity type in the substrate, spaced apart from the first region. A continuous first channel region is defined between the first region and the second region. A plurality of floating gates are spaced apart from one another with each positioned over a separate portion of the channel region. A plurality of control gates are provided with each associated with and adjacent to a floating gate. Each control gate has two portions: a first portion over a portion of the channel region and a second portion over the associated floating gate and capacitively coupled thereto.
    Type: Application
    Filed: August 26, 2016
    Publication date: February 2, 2017
    Inventors: Yuniarto Widjaja, John W. Cooksey, Changyuan Chen, Feng Gao, Ya-Fen Lin, Dana Lee
  • 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: 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: 9548130
    Abstract: A non-volatile memory system comprises a plurality of memory cells arranged in a three dimensional structure and one or more control circuits in communication with the memory cells. The one or more control circuits are configured to program and verify programming for the memory cells. The verifying programming of the plurality of memory cells includes verifying programming for a first data state using a verify operation for a second data state. In one embodiment, the one or more control circuits are also configured to sense whether different memory cells of the plurality of memory cells are in different data states by applying different bit line voltages to the different memory cells.
    Type: Grant
    Filed: August 4, 2015
    Date of Patent: January 17, 2017
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Deepanshu Dutta, Huai-Yuan Tseng, Dana Lee, Ken Oowada, Shih-Chung Lee
  • 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: 9501400
    Abstract: In a block-erasable nonvolatile memory array, blocks are categorized as bad blocks, prime blocks, and sub-prime blocks. Sub-prime blocks are identified from their proximity to bad blocks or from testing. Sub-prime blocks are configured for limited operation (e.g. only storing non-critical data, or data copied elsewhere, or using some additional or enhanced redundancy scheme).
    Type: Grant
    Filed: November 13, 2013
    Date of Patent: November 22, 2016
    Assignee: SanDisk Technologies LLC
    Inventors: Chun Sum Yeung, Jian Chen, Aaron Lee, Abhijeet Manohar, Chris Avila, Dana Lee, Jianmin Huang
  • Publication number: 20160300620
    Abstract: A non-volatile memory system comprises a plurality of memory cells arranged in a three dimensional structure and one or more control circuits in communication with the memory cells. The one or more control circuits are configured to program and verify programming for the memory cells. The one or more control circuits are configured to apply a reference voltage to the memory cells. While applying the reference voltage to the plurality of memory cells, the one or more control circuits are configured to sense whether different memory cells of the plurality of memory cells are in different data states by applying different bit line voltages to different bit lines connected to the different memory cells.
    Type: Application
    Filed: August 4, 2015
    Publication date: October 13, 2016
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: Deepanshu Dutta, Huai-Yuan Tseng, Dana Lee, Ken Oowada, Shih-Chung Lee
  • Publication number: 20160300619
    Abstract: A non-volatile memory system comprises a plurality of memory cells arranged in a three dimensional structure and one or more control circuits in communication with the memory cells. The one or more control circuits are configured to program and verify programming for the memory cells. The verifying programming of the plurality of memory cells includes verifying programming for a first data state using a verify operation for a second data state. In one embodiment, the one or more control circuits are also configured to sense whether different memory cells of the plurality of memory cells are in different data states by applying different bit line voltages to the different memory cells.
    Type: Application
    Filed: August 4, 2015
    Publication date: October 13, 2016
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: Deepanshu Dutta, Huai-Yuan Tseng, Dana Lee, Ken Oowada, Shih-Chung Lee
  • Patent number: 9460799
    Abstract: Techniques for recovery of partially programmed blocks in non-volatile storage are disclosed. After programming memory cells in an open region of a partially programmed block, a fail bit count with respect to programming the memory cells is performed. If the fail bit count is above a threshold, then a recovery operation is performed of other memory cells in the partially programmed block. The recovery operation (such as erase) may remove charges that are trapped in the tunnel dielectric of memory cells in the open region of the partially programmed block. Note that this erase operation may be performed on memory cells in the open region that are already erased. The erase operation may remove trapped charges from the tunnel dielectric. In a sense, this “resets” the memory cells. Thus, the memory cells can now be programmed more effectively. Both programming and date retention may be improved.
    Type: Grant
    Filed: November 24, 2015
    Date of Patent: October 4, 2016
    Assignee: SanDisk Technologies LLC
    Inventors: Xiying Costa, Dana Lee, Zhenming Zhou
  • Patent number: 9459881
    Abstract: A storage controller is configured to find a last-written page in a block in a memory by sending a command to the memory to read a page of data, receiving at least some of the data from that page, and analyzing the at least some of the data from that page to determine if that page is a written page. In one embodiment, the storage controller instructs the memory to read the page of data using a sense time that is shorter than a sense time used to read a page of data in response to a read request from a host controller. Additionally or alternatively, the amount of the data received by the storage controller can be less than the amount of data received when reading a page of data in response to a read request from a host controller.
    Type: Grant
    Filed: May 15, 2014
    Date of Patent: October 4, 2016
    Assignee: SanDisk Technologies LLC
    Inventors: Daniel E. Tuers, Dana Lee, Abhijeet Manohar, Yosief Ataklti
  • 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: 9449693
    Abstract: A split gate NAND flash memory structure is formed on a semiconductor substrate of a first conductivity type. The NAND structure comprises a first region of a second conductivity type in the substrate with a second region of the second conductivity type in the substrate, spaced apart from the first region. A continuous first channel region is defined between the first region and the second region. A plurality of floating gates are spaced apart from one another with each positioned over a separate portion of the channel region. A plurality of control gates are provided with each associated with and adjacent to a floating gate. Each control gate has two portions: a first portion over a portion of the channel region and a second portion over the associated floating gate and capacitively coupled thereto.
    Type: Grant
    Filed: June 27, 2014
    Date of Patent: September 20, 2016
    Assignee: Silicon Storage Technology, Inc.
    Inventors: Yuniarto Widjaja, John W. Cooksey, Changyuan Chen, Feng Gao, Ya-Fen Lin, Dana Lee
  • Patent number: 9430322
    Abstract: A system for improving the management and usage of blocks based on intrinsic endurance may be used to improve memory usage for flash memory, such as a memory card. The overall card endurance may be extended by cycling blocks with higher intrinsic endurance over the lowest endurance target of the worst block. This may be accomplished by managing blocks with different intrinsic endurance values internally or by partitioning the blocks with different intrinsic endurance values externally for different usage.
    Type: Grant
    Filed: August 2, 2012
    Date of Patent: August 30, 2016
    Assignee: SanDisk Technologies LLC
    Inventors: Jonathan Wolfman, Dana Lee, Jonathan Hsu
  • 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
  • Publication number: 20160162353
    Abstract: A method of operating a data storage device having a memory includes reading error location data associated with a first region of the memory. The memory includes the first region and a second region. The method also includes generating one or more parameters based on the error location data. The method includes receiving data to be written to the memory and encoding the data to produce a codeword. The method also includes partitioning the codeword based on the one or more parameters to generate a first portion and a second portion. The method further includes performing a write operation to store the first portion at the first region and to store the second portion at the second region.
    Type: Application
    Filed: March 16, 2015
    Publication date: June 9, 2016
    Inventors: ABHIJEET MANOHAR, DANIEL EDWARD TUERS, DANA LEE
  • 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: 9355713
    Abstract: In a Multi Level Cell (MLC) memory array block in which lower pages are written first, before any upper pages, the lower page data is subject to an exclusive OR (XOR) operation so that if any lower page becomes uncorrectable by ECC (UECC) then the page can be recovered using XOR. Lower pages in such blocks may be written in nonsequential order.
    Type: Grant
    Filed: October 30, 2014
    Date of Patent: May 31, 2016
    Assignee: SanDISK Technologies Inc.
    Inventors: Jianmin Huang, Bo Lei, Jun Wan, Gerrit Jan Hemink, Steven T. Sprouse, Dana Lee
  • Patent number: D763293
    Type: Grant
    Filed: January 20, 2015
    Date of Patent: August 9, 2016
    Assignee: Microsoft Corporation
    Inventors: Dana Lee, Jose Alberto Rodriguez, Conroy Williamson