Threshold Setting (e.g., Conditioning) Patents (Class 365/185.24)
  • Patent number: 8913437
    Abstract: A method includes selecting a first memory cell located along a first bit line and a first word line of a memory array. The method further includes selecting a second memory cell located along (i) the first word line, (ii) a second word line that is adjacent to the first word line, or (iii) a second bit line that is adjacent to the first bit line. A location of the second memory cell is selected based on a predetermined sequence of programming the memory cells. The method further includes writing data in the first memory cell, subsequently writing data in the second memory cell, and reading the first memory cell and the second memory cell. The method further includes detecting one or more states of the second memory causing interference to the first memory cell.
    Type: Grant
    Filed: December 13, 2012
    Date of Patent: December 16, 2014
    Assignee: Marvell World Trade Ltd.
    Inventors: Shashi Kiran Chilappagari, Zhengang Chen, Gregory Burd
  • Publication number: 20140362643
    Abstract: A nonvolatile semiconductor memory device according to an embodiment includes a memory cell array having a plurality of electrically rewritable memory transistors arranged therein; and a control unit configured to govern control that repeats a voltage application operation and a step-up operation, the voltage application operation applying an applied voltage to a selected memory transistor to change a threshold voltage at which the selected memory transistor is conductive, and the step-up operation, in the case where a threshold voltage of the selected memory transistor has not changed to a desired value, raising the applied voltage by an amount of a certain step-up value. The control unit is configured to control the step-up operation to monotonically decrease the step-up value as the number of times of the voltage application operations increases.
    Type: Application
    Filed: January 9, 2014
    Publication date: December 11, 2014
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Naoki YASUDA, Yoshiaki FUKUZUMI
  • Patent number: 8908437
    Abstract: The present disclosure includes methods and devices for determining sensing voltages. One such method includes comparing data associated with a number of template distributions to data associated with a first threshold voltage distribution and a second threshold voltage distribution associated with a number of memory cells programmed to particular adjacent program states, determining an intersection of the first and second threshold voltage distributions based on a template distribution of the number template distributions which most closely compares to the first and second threshold voltage distributions, and using the determined intersection to determine a sensing voltage used to sense the number of memory cells programmed to the particular adjacent program states.
    Type: Grant
    Filed: August 6, 2013
    Date of Patent: December 9, 2014
    Assignee: Micron Technology, Inc.
    Inventor: Andre Ghilardelli
  • Patent number: 8902666
    Abstract: A method of programming memory cells (transistors) of a nonvolatile memory device from a first set of (previous) logic states to a second set of (final) logic states. The method includes applying program voltages to selected memory transistors; and applying a pre-verification voltage and a target verification voltage for verifying the current logic state of the selected memory transistors. The voltage interval between logic states of the second set of logic states is less than the voltage interval between logic states of the first set of logic states. A target verification voltage for verifying a first memory transistor is at one logic state of the second set is used as a pre-verification voltage for verifying that a second memory transistor to be programmed to higher logic state of the second set.
    Type: Grant
    Filed: April 10, 2012
    Date of Patent: December 2, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Sangyong Yoon, Kitae Park
  • Patent number: 8902648
    Abstract: Methods for determining a program window and memory devices are disclosed. One such method for determining the program window measures an amount of program disturb experienced by a particular state and determines the program window responsive to the amount of program disturb.
    Type: Grant
    Filed: July 26, 2011
    Date of Patent: December 2, 2014
    Assignee: Micron Technology, Inc.
    Inventors: Tommaso Vali, Giovanni Santin, Massimo Rossini, William H. Radke, Violante Moschiano
  • Patent number: 8897066
    Abstract: A method of programming a nonvolatile memory device includes sequentially programming first to (n?1)th logical pages of all the physical pages of a first memory block of the memory blocks in response to a first program command, a step of loading data of the first to (n?1)th logical pages stored in a first physical page of the first memory block and latching the loaded data in first to (n?1)th latches of each of the page buffers, respectively, when receiving a second program command after programming all the first to (n?1)th logical pages, and latching new program data, received along with the second program command, in an nth latch of the corresponding page buffer and programming the data, stored in the first to nth latches of the page buffer, into a first physical page of a second memory block of the memory blocks.
    Type: Grant
    Filed: December 29, 2011
    Date of Patent: November 25, 2014
    Assignee: Hynix Semiconductor Inc.
    Inventor: Min Joong Jung
  • Patent number: 8897078
    Abstract: Various embodiments include methods, apparatus, and systems for reading an adjacent cell of a memory array in an electronic device to determine a threshold voltage value of the adjacent cell, the adjacent cell being adjacent a target cell, and reading the target cell of the memory array using a wordline voltage value based on the threshold voltage value of the adjacent cell. Additional apparatus, systems, and methods are described.
    Type: Grant
    Filed: June 11, 2013
    Date of Patent: November 25, 2014
    Assignee: Micron Technology, Inc.
    Inventor: Seiichi Aritome
  • Patent number: 8897073
    Abstract: A non-volatile memory device comprises an array of memory cells and a charge pump coupled to the memory cells. The charge pump is dynamically reconfigurable to operate in a bypass mode to provide a first voltage to the memory cells, a program mode to provide the first voltage to the memory cells, and an erase mode to provide a second voltage that has inverse polarity of the first voltage.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: November 25, 2014
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Horacio P. Gasquet, Jeffrey C. Cunningham
  • Patent number: 8891304
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a memory cell array includes blocks, each of the blocks includes NAND strings that each comprise memory cells serially connected in a first direction, word lines respectively connected to memory cell groups arranged in a second direction in the block, and a controller configured to perform a process (A) of verifying one of states in which all of the memory cells included in the block are turned on (pass) and at least one memory cell is turned off (fail) by use of a first read voltage applied to unselected word lines in a data read time, and to perform a process (B) of reading data from the fail block by use of a second read voltage that is higher than the first read voltage and applied to the unselected word lines.
    Type: Grant
    Filed: March 3, 2011
    Date of Patent: November 18, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Hiroyuki Nagashima
  • Patent number: 8891321
    Abstract: The present disclosure includes methods, devices, and systems for outputting data particular quantization of data from memory devices and systems. Outputting data particular quantization of data can include enabling a particular one of a plurality of different quantizations of data. The particular one of the plurality of quantizations of data can then be output.
    Type: Grant
    Filed: May 21, 2013
    Date of Patent: November 18, 2014
    Assignee: Micron Technology, Inc.
    Inventor: Theodore T. Pekny
  • Patent number: 8891312
    Abstract: Memory cells of a nonvolatile memory array are characterized by one of multiple threshold voltage ranges including at least an erased threshold voltage range and a programmed threshold voltage range. Responsive to an erase command to erase a group of memory cells of the nonvolatile memory array, a plurality of phases are performed, including at least a pre-program phase and an erase phase. The pre-program phase programs a first set of memory cells in the group having threshold voltages within the erased threshold voltage range, and does not program a second set of memory cells in the group having threshold voltages within the erased threshold voltage range in the group. By not programming the second set of memory cells, the pre-program phase is performed more quickly than if the second set of memory cells were programmed along with the first set of memory cells.
    Type: Grant
    Filed: April 23, 2012
    Date of Patent: November 18, 2014
    Assignee: Macronix International Co., Ltd.
    Inventors: Chun-Yi Lee, Kuen-Long Chang, Chun-Hsiung Hung
  • Patent number: 8891300
    Abstract: In one embodiment, the method includes overwriting a memory cell storing m-bit data to store n-bit data, where n is less than or equal to m. The memory cell has one of a first plurality of program states when storing the m-bit data, and the memory cell has one of a second plurality of program states when storing the n-bit data. The second plurality of program states include at least one program state not in the first plurality of program states.
    Type: Grant
    Filed: January 22, 2013
    Date of Patent: November 18, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Eun Chu Oh, Jaehong Kim, Jongha Kim, Junjin Kong
  • Patent number: 8885406
    Abstract: A memory device includes: a plurality of nonvolatile memory sections configured to allow one memory cell to record data of a plurality of bits, and to include a corresponding number of pages to the plurality of bits in accordance with a plurality of the memory cells as a write control unit; and a control section configured to control writing and reading data to and from the plurality of nonvolatile memory sections, wherein among the plurality of nonvolatile memory sections, if data is written into one of the nonvolatile memory sections, the data is written for each page in sequence from a low-order page to a high-order page, and when the data is written into the low-order page, control is performed such that the data to be written into the low-order page is written into any area of the other of the nonvolatile memory sections at same timing.
    Type: Grant
    Filed: April 19, 2013
    Date of Patent: November 11, 2014
    Assignee: Sony Corporation
    Inventors: Yuto Hosogaya, Shingo Aso
  • Patent number: 8885415
    Abstract: A system including a read module to perform a first read operation to determine a state of a memory cell, and in response to a first failure to decode data read from the memory cell, perform second and third read operations to determine the state of the memory cell. The memory cell has first and second threshold voltages when programmed to first and second states, respectively. A shift detection module detects, in response to a second failure to decode data read from the memory cell in the second and third read operations, a shift in a distribution of at least one of the first and second threshold voltages. A binning module divides the distribution into a plurality of bins. A log-likelihood ratio (LLR) module generates LLRs for the plurality of bins based on a variance of the distribution and adjusts the LLRs based on an amount of the shift.
    Type: Grant
    Filed: September 9, 2013
    Date of Patent: November 11, 2014
    Assignee: Marvell World Trade Ltd.
    Inventors: Shashi Kiran Chilappagari, Xueshi Yang
  • Patent number: 8885405
    Abstract: A flash memory includes a program voltage generator, plural memory units, a current limiter, and a multi-bit program control unit. The program voltage generator is used for providing a constant program voltage during a detecting cycle and providing a dynamically-adjustable program voltage during a program cycle. The plural memory units output plural drain currents and plural data line voltages to plural data lines. The current limiter is used for receiving a reference current and a reference voltage, thereby controlling the plural drain currents. During the detecting cycle, a specified data line voltage of the plural data line voltages with the minimum voltage level is detected by the multi-bit program control unit. During the program cycle, the specified data line voltage is used as a feedback voltage, and the dynamically-adjustable program voltage is generated by the program voltage generator according to the feedback voltage.
    Type: Grant
    Filed: January 31, 2013
    Date of Patent: November 11, 2014
    Assignee: eMemory Technology Inc.
    Inventors: Che-Wei Chang, Chia-Fu Chang, Yu-Hsiung Tsai, Chia-Jung Hsu
  • Patent number: 8885417
    Abstract: In writing, a first write operation to a first memory cell is executed; and a second write operation for providing a first threshold-voltage distribution to a second memory cell adjacent to the first one, is executed. The first threshold voltage distribution is a lowest threshold-voltage distribution among the positive threshold voltage distributions. It is verified whether a desired threshold voltage distribution has been obtained in the first memory cell or not (first write verify operation), moreover, it is verified whether a first threshold voltage distribution or a threshold voltage distribution having a voltage level larger than the first threshold-voltage distribution has been obtained in the second memory cell or not (second write verify operation). A control circuit outputs results of the first write verify operation and the second write verify operation.
    Type: Grant
    Filed: October 4, 2013
    Date of Patent: November 11, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yasushi Nagadomi, Naoya Tokiwa
  • Patent number: 8879344
    Abstract: Methods and systems for time-based cell decoding for PCM memory. Generally, the higher the PCM element resistance, the longer it takes for a read output to change state. PCM memory output is determined using differentiated timings of read outputs changing state, rather than differentiated values of read outputs. In some single-bit single-ended sensing embodiments, a reference, with resistance between the resistances corresponding to a pair of adjacent logical states, is stored in multiple reference cells; a “vote” unit emits a clock signal when a majority of the reference cell read outputs transition at the vote unit. Timing units produce different binary outputs depending on whether a data read output or the clock signal changes state first at the timing unit. Time-based decoding provides advantages including improved temperature and drift resilience, improved state discrimination, improved reliability of multibit PCM, and fast and reliable sensing.
    Type: Grant
    Filed: April 1, 2014
    Date of Patent: November 4, 2014
    Inventors: Aaron D. Willey, Ryan Jurasek
  • Patent number: 8879325
    Abstract: A flash memory controller, a non-transitory computer readable medium and a method for reading flash memory cells of a flash memory module. The method may include calculating a group of read thresholds to be applied during a reading operation of a set of flash memory cells that belong to a certain row of the flash memory module based upon a compressed representation of reference read thresholds associated with multiple reference rows of the flash memory module; and reading the set of flash memory cells by applying the group of reference read thresholds to provide read results.
    Type: Grant
    Filed: May 30, 2012
    Date of Patent: November 4, 2014
    Assignee: Densbits Technologies Ltd.
    Inventors: Ilan Bar, Hanan Weingarten
  • Patent number: 8879331
    Abstract: Methods for programming and reading memory cells using a shared bit line string architecture are described. In some embodiments, memory cells and select devices may correspond with transistors including a charge storage layer. In some cases, the charge storage layer may be conductive (e.g., a polysilicon layer as used in a floating gate device) or non-conductive (e.g., a silicon nitride layer as used in a SONOS device). In some embodiments, selection of a memory cell in a first string of a pair of strings may include setting an SEO transistor into a conducting state and setting an SGD line controlling drain-side select transistors to a voltage that is greater than a first threshold voltage associated with a first drain-side select transistor of the first string and less than a second threshold voltage associated with a second drain-side select transistor of a second string of the pair of strings.
    Type: Grant
    Filed: March 12, 2013
    Date of Patent: November 4, 2014
    Assignee: Sandisk Technologies Inc.
    Inventors: Jongsun Sel, Seungpil Lee, Kwang-Ho Kim, Tuan Pham
  • Patent number: 8879317
    Abstract: Systems and methods to decode data stored in a data storage device are disclosed. Data bits stored in a first group of storage elements are decoded using data in a second group of storage elements together with physical characteristics of the second group of storage elements to aid in the decoding of the first group of storage elements.
    Type: Grant
    Filed: February 21, 2012
    Date of Patent: November 4, 2014
    Assignee: Sandisk Technologies Inc.
    Inventors: Simon Litsyn, Idan Alrod, Eran Sharon
  • Publication number: 20140321207
    Abstract: The present disclosure includes apparatuses and methods for determining soft data for combinations of memory cells. A number of embodiments include an array of memory cells, wherein the array includes a first memory cell and a second memory cell, wherein the first and second memory cells are each programmable to one of a number of program states, and wherein a combination of the program states of the first and second memory cells corresponds to one of a number of data states. A number of embodiments also include a buffer and/or a controller coupled to the array and configured to determine soft data associated with the program states of the first and second memory cells and determine soft data associated with the data state that corresponds to the combination of the program states of the first and second memory cells based, at least in part, on the soft data associated with the program state of the first memory cell and the soft data associated with the program state of the second memory cell.
    Type: Application
    Filed: April 23, 2014
    Publication date: October 30, 2014
    Applicant: Micron Technology, Inc.
    Inventors: Violante Moschiano, Tommaso Vali, Mark A. Hawes
  • Publication number: 20140321215
    Abstract: Methods and controllers for programming a memory are provided. In one such method, a potential for pillars of the memory that are to be inhibited is lowered, and programming cells of the memory is accomplished while the pillars of the memory that are to be inhibited have the lower potential.
    Type: Application
    Filed: April 24, 2013
    Publication date: October 30, 2014
    Applicant: Micron Technology, Inc.
    Inventor: Koji SAKUI
  • Publication number: 20140321216
    Abstract: Embodiments are provided that include a method including providing a first pulsed gate signal to a selected memory cell, wherein the pulsed gate signal alternates between a first voltage level and a second voltage level during a time period and sensing a data line response to determine data stored on the selected memory of cells. Further embodiments provide a system including a memory device, having a regulator circuit coupled to a plurality of access lines of a NAND memory cell, and a switching circuit configured to sequentially bias at least one of the plurality of the access lines between a first voltage level and a second voltage level based on an input signal.
    Type: Application
    Filed: July 14, 2014
    Publication date: October 30, 2014
    Inventor: Toru Tanzawa
  • Patent number: 8873286
    Abstract: Apparatuses, systems, and methods are disclosed to manage non-volatile media. A method includes determining a configuration parameter for a set of storage cells of a non-volatile recording medium. A method includes reading data from a set of storage cells using a determined configuration parameter. A method includes adjusting a configuration parameter based on read data.
    Type: Grant
    Filed: December 13, 2013
    Date of Patent: October 28, 2014
    Assignee: Intelligent Intellectual Property Holdings 2 LLC
    Inventors: John Strasser, David Flynn, Jeremy Fillingim, Robert Wood, Jea Hyun, Hairong Sun
  • Patent number: 8873300
    Abstract: A semiconductor memory device is provided. The semiconductor memory device includes memory cells having first to fourth middle states corresponding to different threshold voltage distributions. The semiconductor memory device also includes a peripheral circuit configured to perform a first program operation to program memory cells having the third and the fourth middle states to have four upper states and perform a second program operation to program memory cells having the first and the second middle states to have another four upper states.
    Type: Grant
    Filed: December 17, 2012
    Date of Patent: October 28, 2014
    Assignee: SK Hynix Inc.
    Inventor: Tae Hoon Kim
  • Patent number: 8867268
    Abstract: Devices, systems, methods, and other embodiments associated with accessing memory using fractional reference voltage are described. In one embodiment, an apparatus includes comparison logic. The comparison logic compares a threshold voltage of a memory cell to at least one pair of reference voltages that are near an integral reference voltage to generate comparison results. The apparatus includes read logic to determine a bit value of the memory cell based, at least in part, on the comparison results.
    Type: Grant
    Filed: March 22, 2013
    Date of Patent: October 21, 2014
    Assignee: Marvell World Trade Ltd.
    Inventors: Xueshi Yang, Zining Wu
  • Patent number: 8867271
    Abstract: In a 3D stacked non-volatile memory device, the threshold voltages are evaluated and adjusted for select gate, drain (SGD) transistors at drain ends of strings of series-connected memory cells. To optimize and tighten the threshold voltage distribution, the SGD transistors are read at lower and upper levels of an acceptable range. SGD transistors having a low threshold voltage are subject to programming, and SGD transistors having a high threshold voltage are subject to erasing, to bring the threshold voltage into the acceptable range. The evaluation and adjustment can be repeated such as after a specified number of program-erase cycles of an associated sub-block. The condition for repeating the evaluation and adjustment can be customized for different groups of SGD transistors. Aspects include programming SGD transistors with verify and inhibit, erasing SGD transistors with verify and inhibit, and both of the above.
    Type: Grant
    Filed: May 30, 2012
    Date of Patent: October 21, 2014
    Assignee: SanDisk Technologies Inc.
    Inventors: Haibo Li, Xiying Costa, Masaaki Higashitani, Man L. Mui
  • Patent number: 8867280
    Abstract: This invention provides a 3D stacked NAND flash memory array and operation method thereof enabling to operate by LSM (a layer selection by multi-level operation) and to get rid of the waste of unnecessary areas by minimizing the number of SSLs needed for a layer selection though the number of layers vertically stacked is increased.
    Type: Grant
    Filed: February 6, 2013
    Date of Patent: October 21, 2014
    Assignee: Seoul National University R&DB Foundation
    Inventors: Byung-Gook Park, Wandong Kim
  • Patent number: 8867270
    Abstract: A method for performing memory access management includes: with regard to a same Flash cell of a Flash memory, receiving a first digital value outputted by the Flash memory, requesting the Flash memory to output at least one second digital value, wherein the first digital value and the at least one second digital value are utilized for determining information of a same bit stored in the Flash cell, and a number of various possible states of the Flash cell correspond to a possible number of bit(s) stored in the Flash cell; based upon the second digital value, generating/obtaining soft information of the Flash cell, for use of performing soft decoding; and controlling the Flash memory to perform sensing operations by respectively utilizing a plurality of sensing voltages that are not all the same, in order to generate the first digital value and the second digital value.
    Type: Grant
    Filed: July 17, 2013
    Date of Patent: October 21, 2014
    Assignee: Silicon Motion Inc.
    Inventors: Tsung-Chieh Yang, Hsiao-Te Chang, Wen-Long Wang
  • Patent number: 8861278
    Abstract: A cache programming method for a non-volatile memory device includes programming data for a current programming operation into a memory cell array, determining whether the current programming operation has been performed to a threshold point of program completion, and receiving a data for a next programming operation when the current programming operation has been performed to the threshold point of program completion.
    Type: Grant
    Filed: November 8, 2011
    Date of Patent: October 14, 2014
    Assignee: Hynix Semiconductor Inc.
    Inventors: You-Sung Kim, Se-Chun Park
  • Patent number: 8861281
    Abstract: A method of programming a memory is provided. The memory has a first cell, having a first S/D region and a second S/D region shared with a second cell. The second cell has a third S/D region opposite to the second S/D region. When programming the first cell, a first voltage is applied to a control gate of the first cell, a second voltage is applied to a control gate of the second cell to slightly turn on a channel of the second cell, a third and a fourth voltage are respectively applied to the first and the third S/D regions, and the second S/D region is floating. A carrier flows from the third S/D region to the first S/D region, and is injected into a charge storage layer of the first cell by source-side injection.
    Type: Grant
    Filed: May 11, 2011
    Date of Patent: October 14, 2014
    Assignee: MACRONIX International Co., Ltd.
    Inventors: Ping-Hung Tsai, Jyun-Siang Huang, Wen-Jer Tsai
  • Patent number: 8861247
    Abstract: Techniques for providing a direct injection semiconductor memory device are disclosed. In one particular exemplary embodiment, the techniques may be realized as a method for biasing a direct injection semiconductor memory device. The method may comprise applying a first voltage potential to a first N-doped region via a bit line and applying a second voltage potential to a second N-doped region via a source line. The method may also comprise applying a third voltage potential to a word line, wherein the word line is spaced apart from and capacitively coupled to a body region that is electrically floating and disposed between the first N-doped region and the second N-doped region. The method may further comprise applying a fourth voltage potential to a P-type substrate via a carrier injection line.
    Type: Grant
    Filed: August 12, 2013
    Date of Patent: October 14, 2014
    Assignee: Micron Technology, Inc.
    Inventors: Yogesh Luthra, Serguei Okhonin, Mikhail Nagoga
  • Publication number: 20140301147
    Abstract: A storage medium including a plurality of memory cells, a plurality of transmission lines, a driving module and a floating detection module is disclosed. The memory cells store data. The transmission lines are coupled to the memory cells. The driving module accesses the memory cells via the transmission lines. The floating detection module includes a reset unit, a plurality of connectors and a detector. The reset unit is coupled to a detection line. Each of the connectors is coupled between one of the transmission lines and the detection line. The detector determines whether a state of at least one of the transmission lines is a floating state according to a level of the detection line.
    Type: Application
    Filed: April 5, 2013
    Publication date: October 9, 2014
    Applicant: Winbond Electronics Corp.
    Inventor: Chih-Jing LAI
  • Patent number: 8854889
    Abstract: A flash memory device and reading method of the flash memory device. The reading method includes determining a read voltage set of memory cells corresponding to a first word line from at least one of flag cell data of the first word line and flag cell data of a second word line adjacent to the first word line, and reading the memory cells corresponding to the first word line according to the determined read voltage set.
    Type: Grant
    Filed: July 30, 2013
    Date of Patent: October 7, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Boh-chang Kim
  • Patent number: 8854878
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a memory cell array and a controller. The controller is configured to perform a verify operation using a first verification voltage and a second verification voltage (first verification voltage<second verification voltage) when first value data is stored in a first memory cell. The controller is configured to determine whether a write operation to the first memory cell is completed or continued based on write data of a second memory cell adjacent to the first memory cell when a threshold voltage of the first memory cell is greater than or equal to the first verification voltage and less than the second verification voltage.
    Type: Grant
    Filed: September 5, 2012
    Date of Patent: October 7, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Mitsuaki Honma
  • Publication number: 20140293699
    Abstract: A nonvolatile memory recycles previously written blocks by reassigning binary logic states and further programming memory cells with modified parameters. Cells are written twice between erase operations, thus reducing wear, and providing higher endurance. Flags indicate whether blocks are recycled, and what parameters to use in programming and reading the blocks.
    Type: Application
    Filed: April 2, 2013
    Publication date: October 2, 2014
    Applicant: SanDisk Technologies Inc.
    Inventors: Nian Niles Yang, Abhijeet Manohar
  • Patent number: 8848439
    Abstract: Described embodiments provide enhanced read accuracy of a multi-level cell (MLC) flash memory. A read request for desired cells is received by a media controller of the memory. The media controller sets m thresholds to initial values, each threshold corresponding to a cell voltage level of the memory, and measures the cell voltage level of a given cell. For each of the desired cells of the memory, the media controller iteratively, until the measured cell voltage level converges on one of the thresholds, compares the measured cell voltage level to the thresholds. If the measured cell voltage level does not converge on one of the thresholds, the media controller updates the thresholds, remeasures the cell voltage level and compares the remeasured cell voltage level to the updated thresholds. Once the measured cell voltage level converges on a threshold, the media controller determines a binary level of the cell.
    Type: Grant
    Filed: August 24, 2012
    Date of Patent: September 30, 2014
    Assignee: LSI Corporation
    Inventors: Fan Zhang, Ming Jin, Abdel-Hakim S. Alhussien
  • Patent number: 8848453
    Abstract: An apparatuses and methods for inferring threshold voltage distributions associated with memory cells via interpolation. A determining soft data for a group of memory cells each programmed to one of a number of data states, wherein the soft data comprises a number of different soft data values, determining a quantity of memory cells associated with each of the different soft data values, and inferring at least a portion of a threshold voltage distribution associated with the group of memory cells via an interpolation process using the determined quantities of memory cells associated with each of the different soft data values.
    Type: Grant
    Filed: August 31, 2012
    Date of Patent: September 30, 2014
    Assignee: Micron Technology, Inc.
    Inventors: Zhenlei Shen, William H. Radke
  • Patent number: 8848456
    Abstract: Provided is an erasing method of a nonvolatile memory device. The erasing method applies a word line erase voltage to a plurality of word lines connected to the memory cells respectively, applies a specific voltage to a ground selection line connected to the ground selection transistor, applies an erase voltage to a substrate in which the memory string formed during the step applying the specific voltage to the ground selection line, and floats the ground selection line in response to a voltage change of the substrate.
    Type: Grant
    Filed: August 15, 2013
    Date of Patent: September 30, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jinman Han, Doogon Kim
  • Patent number: 8848442
    Abstract: To store input data in a plurality of memory cells, a mapping function of bit sequences to physical parameter states of the cells is provided. The cells are programmed, in accordance with the mapping function, to store the input data, in a way that would store uniformly distributed data with a programming state distribution other than any native state distribution of the mapping function. To store input data in a single memory cell, a mapping function of bit sequences to states of a physical parameter of the cell, such that if uniformly distributed data were stored in a plurality of such memory cells then the states of the physical parameter of the cells would be distributed non-uniformly, is provided. The memory cell is programmed to store the input data in accordance with the mapping function.
    Type: Grant
    Filed: December 23, 2010
    Date of Patent: September 30, 2014
    Assignee: Sandisk IL Ltd.
    Inventors: Eran Sharon, Idan Alrod
  • Patent number: 8848440
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device comprises a memory cell array including memory cell transistors configured to store information in accordance with n (n is an integer larger than 2) threshold voltage levels, and a control circuit configured to control the memory cell array. In a write operation, the control circuit shifts a threshold voltage level of a write target memory cell transistor to a base threshold level of the n threshold levels, except for a threshold level having a highest voltage and a threshold level having a lowest voltage. Then the control circuit shifts the threshold voltage level of the write target memory cell transistor from the base threshold level to one of the n threshold levels.
    Type: Grant
    Filed: July 26, 2013
    Date of Patent: September 30, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Naoki Yasuda, Masaru Kito
  • Patent number: 8848421
    Abstract: A forming method of a variable resistance nonvolatile memory element capable of lowering a forming voltage and preventing variations of the forming voltage depending on variable resistance elements. The forming method is for initializing a variable resistance element, including a step (S24) of determining whether or not a current flowing in a 1T1R memory cell is greater than a reference current; a step (S22) of applying a forming positive voltage pulse having a pulse width (Tp(n)) is gradually increased when it is determined that the current is not greater than the reference current; and a step (S23) of applying a negative voltage pulse having a pulse width Tn equal to or shorter than a pulse width Tp(n). The determining step (S24), the application step (S22), and the application step (S23) are repeated until the forming becomes successful.
    Type: Grant
    Filed: March 28, 2011
    Date of Patent: September 30, 2014
    Assignee: Panasonic Corporation
    Inventors: Ken Kawai, Kazuhiko Shimakawa, Koji Katayama
  • Publication number: 20140286105
    Abstract: A NAND flash memory unit, an operating method and a reading method are provided. The NAND flash memory unit includes a plurality of gate layers, a tunnel layer, a charge trapping layer, a conductor layer and a second dielectric layer. A first dielectric layer is included between two adjacent gate layers among the gate layers. The tunnel layer, the charge trapping layer, the conductor layer, and the second dielectric layer penetrate the gate layers. The charge trapping layer is disposed between the tunnel layer and the gate layers, and the second dielectric layer is disposed between the conductor layer and the tunnel layer. Therefore, an erasing speed may be increased; the charge trapping layer may be repaired; the controllability of the gate layers may be increased.
    Type: Application
    Filed: June 13, 2013
    Publication date: September 25, 2014
    Inventors: Wei Lin, Yu-Cheng Hsu, Kuo-Yi Cheng
  • Publication number: 20140286106
    Abstract: Memory devices, memory cell strings and methods of operating memory devices are shown. Configurations described include directly coupling an elongated body region to a source line. Configurations and methods shown should provide a reliable bias to a body region for memory operations such as erasing.
    Type: Application
    Filed: June 9, 2014
    Publication date: September 25, 2014
    Inventor: Akira Goda
  • Patent number: 8842479
    Abstract: A memory device includes a plurality of memory cells arranged in series in the semiconductor body, such as a NAND string, having a plurality of word lines. A selected memory cell is programmed by hot carrier injection. The program operation is based on metering a flow of carriers between a first semiconductor body region on a first side of the selected cell in the NAND string and a second semiconductor body region on a second side of the selected cell. A program potential higher than a hot carrier injection barrier level is applied to the selected cell, and then the drain to source voltage across the selected cell and the flow of carriers in the selected cell reach a level sufficient to support hot carrier injection, which is controlled by a combination of a switch cell adjacent the selected cell and modulation of a source side voltage applied to the NAND string.
    Type: Grant
    Filed: October 11, 2011
    Date of Patent: September 23, 2014
    Assignee: Macronix International Co., Ltd.
    Inventors: Jyun-Siang Huang, Wen-Jer Tsai, Ping-Hung Tsai
  • Patent number: 8842476
    Abstract: Methods and non-volatile storage systems are provided for determining erratically programmed storage elements, including under-programmed and over-programmed storage elements. Techniques do not require any additional data latches. A set of data latches may be used to store program data for a given memory element. This program data may be maintained after the programming is over for use in erratic program detection. In one embodiment, lockout status is kept in a data latch that is used to serially receive program data to be programmed into the storage element. Therefore, no extra data latches are required to program the storage elements and to maintain the program data afterwards.
    Type: Grant
    Filed: November 9, 2011
    Date of Patent: September 23, 2014
    Assignee: SanDisk Technologies Inc.
    Inventors: Manabu Sakai, Toru Miwa
  • Publication number: 20140269100
    Abstract: Methods for programming and reading memory cells using a shared bit line string architecture are described. In some embodiments, memory cells and select devices may correspond with transistors including a charge storage layer. In some cases, the charge storage layer may be conductive (e.g., a polysilicon layer as used in a floating gate device) or non-conductive (e.g., a silicon nitride layer as used in a SONOS device). In some embodiments, selection of a memory cell in a first string of a pair of strings may include setting an SEO transistor into a conducting state and setting an SGD line controlling drain-side select transistors to a voltage that is greater than a first threshold voltage associated with a first drain-side select transistor of the first string and less than a second threshold voltage associated with a second drain-side select transistor of a second string of the pair of strings.
    Type: Application
    Filed: March 12, 2013
    Publication date: September 18, 2014
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: Jongsun Sel, Seungpil Lee, Kwang-Ho Kim, Tuan Pham
  • Publication number: 20140269055
    Abstract: Each memory cell has a threshold voltage to distinguish a storage data item. A controller generates one of storage data items from one or more sets of reception data, stores the storage data item, randomizes data transmission for memory cells, instructs the cells to store the randomized data, uses read voltage candidates to read storage data from the cells, counts a distribution of voltages stored in the cells for each read voltage candidate, specifies a minimum read voltage candidate where a sum of the counting exceeds an expected number, and uses the specified candidate as a read voltage to distinguish a first storage data item corresponding to the expected number and an adjacent second storage data item.
    Type: Application
    Filed: July 22, 2013
    Publication date: September 18, 2014
    Applicant: Kabushiki Kaisha Toshiba
    Inventor: Yasuhiko KUROSAWA
  • Publication number: 20140269079
    Abstract: A nonvolatile semiconductor memory device according to an embodiment includes a memory cell array that includes NAND cell units; and a write/erase circuit configured to execute a select gate write operation, the select gate write operation executing a programming operation for setting a threshold voltage of a drain side select gate and a verify operation for judging whether said threshold voltage has reached a certain value, and, when it is judged by the verify operation on the drain side select gate that the threshold voltage of the drain side select gate has not reached the certain value, repeatedly executing a programming operation for setting a threshold voltage of a drain side dummy cell connected to the drain side select gate and a verify operation for judging whether said threshold voltage has reached a certain value, until the threshold voltage of the drain side dummy cell has reached the certain value.
    Type: Application
    Filed: September 10, 2013
    Publication date: September 18, 2014
    Applicant: Kabushiki Kaisha Toshiba
    Inventor: Takeshi KAMIGAICHI
  • Publication number: 20140269101
    Abstract: A memory cell is programmed to at least a first threshold voltage to indicate a particular data value. After waiting for a relaxation time, the memory cell is programmed to at least a second threshold voltage to indicate the particular data value. The second threshold voltage is greater than the first threshold voltage.
    Type: Application
    Filed: May 29, 2014
    Publication date: September 18, 2014
    Applicant: MICRON TECHNOLOGY, INC.
    Inventor: Toru Tanzawa