Erase Patents (Class 365/185.29)
  • Publication number: 20150003170
    Abstract: A nonvolatile memory device includes: a plurality of cell strings disposed on a substrate, wherein at least one of the plurality of cell strings comprises a plurality of cell transistors and at least one ground select transistor stacked in a direction substantially perpendicular to the substrate, and the substrate and a channel region of the plurality of cell strings have a same conductivity type; a substrate bias circuit configured to provide an erase voltage to the substrate in an erase operation; and a ground select line voltage generator configured to provide a ground select line saturation voltage to the at least one ground select transistor in the erase operation.
    Type: Application
    Filed: June 13, 2014
    Publication date: January 1, 2015
    Inventors: Ju-hyung Kim, Chang-seok Kang, Young-suk Kim
  • Patent number: 8923064
    Abstract: A semiconductor memory device includes a memory array including a plurality of memory cells, and a peripheral circuit configured to perform an erase operation by supplying a first erase voltage to selected memory cells and perform an erase verify operation by supplying an erase verify voltage to the selected memory cells, wherein the peripheral circuit is configured to increase the first erase voltage to a first level at a first rising rate for a first rising period and increase the first erase voltage to a first target level at a second rising rate lower than the first rising rate for a second rising period.
    Type: Grant
    Filed: December 5, 2012
    Date of Patent: December 30, 2014
    Assignee: SK Hynix Inc.
    Inventors: Noh Yong Park, Hyung Seok Kim
  • Patent number: 8923054
    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: January 10, 2014
    Date of Patent: December 30, 2014
    Assignee: SanDisk Technologies Inc.
    Inventors: Xiying Costa, Alexander Kwog-Tung Mak, Chris Avila, Gautam Dusija, Man Mui
  • Patent number: 8923046
    Abstract: A semiconductor memory device includes a memory cell array including first memory cells and second memory cells connected to at least one word line, a circuit group configured to perform a pre-program operation on the first memory cells using a target voltage and a main program operation on the first memory cells and the second memory cells using a final target voltage, and a control circuit configured to set the target voltage depending on variations in threshold voltages of the first memory cells caused by the main program operation of the second memory cells.
    Type: Grant
    Filed: August 31, 2012
    Date of Patent: December 30, 2014
    Assignee: SK Hynix Inc.
    Inventor: Yoo Hyun Noh
  • Patent number: 8923072
    Abstract: Disclosed are a non-volatile memory device and a method of fabricating the same. The non-volatile memory device includes a semiconductor substrate including a plurality of active regions and a pair of first pillars protruding from each active region. A pair of drain selection lines surround each pillar of the pair of first pillars. A pair of second pillars, wherein each second pillar is disposed over a corresponding first pillar, of the pair of the first pillars, and is formed of a semiconductor material. A plurality of word lines and a source selection line form a stack that surrounds the pair of second pillars. A source line is formed over and connected with the pair of second pillars. Drain contacts are formed at both sides of each active region except between pairs of the drain selection lines. A bit line is formed over and connected with the drain contacts.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: December 30, 2014
    Assignee: SK Hynix Inc.
    Inventor: Seul-Ki Oh
  • Patent number: 8917559
    Abstract: A method may be performed by a data storage device and includes writing first data to a group of storage elements. Each particular storage element of the group of storage elements is assigned to a particular state of a first set of states based on a first data value to be stored in the particular storage element. The method also includes overwriting the first data in the group of storage elements with second data. Each particular storage element of the group of storage elements is assigned to a particular state of a second set of states based on a second data value to be stored in the particular storage element. At least one state is included in the first set of states and is excluded from the second set of states.
    Type: Grant
    Filed: May 7, 2012
    Date of Patent: December 23, 2014
    Assignee: SanDisk Technologies Inc.
    Inventor: Omprakash Bisen
  • Patent number: 8917558
    Abstract: Nonvolatile memory device, operating methods thereof, and memory systems including the same. In the operating method, a ground select line of a first string connected to a bit line may be floated. An erase prohibition voltage may be applied to a ground select line of a second string connected to the bit line. An erase operation voltage may be applied to the first and second strings.
    Type: Grant
    Filed: January 6, 2011
    Date of Patent: December 23, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jinman Han, Donghyuk Chae
  • Patent number: 8918584
    Abstract: A method and apparatus for refreshing data in a flash memory device is disclosed. A counter is maintained for each memory block. When a memory block is erased, the counter for that erase block is set to a predetermined value while the remaining counters for other erase blocks are changed. When a memory block counter reaches a predetermined threshold value, the associated memory block is refreshed.
    Type: Grant
    Filed: January 9, 2014
    Date of Patent: December 23, 2014
    Assignee: Micron Technology, Inc.
    Inventor: Shuba Swaminathan
  • Patent number: 8917552
    Abstract: A control circuit for a nonvolatile semiconductor storage device, during a write operation, configures multiple bit lines so that bit lines that are adjacent to select bit lines are nonselect bit lines. The control circuit applies a first voltage to a write bit line that is included in the select bit lines, and also applies a second voltage that is higher than the first voltage, to a write inhibit bit line that is included in the select bit lines. Then, the control circuit applies a third voltage that is higher than the second voltage to the nonselect bit lines. As a result, the control circuit raises the voltage of the write inhibit bit line, while maintaining the write bit line at the first voltage. Next, the control circuit applies a fourth voltage for the write operation to the drain-side select gate line.
    Type: Grant
    Filed: March 3, 2013
    Date of Patent: December 23, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Takashi Maeda
  • Patent number: 8917554
    Abstract: Word line switch transistors in a well in a substrate may be back biased. A memory array having non-volatile storage devices may be in a separate well in the substrate. The well of the word line switch transistors may be biased separately from the well of the non-volatile storage devices. Word line switch transistors may be back-biased during an erase operation. A first voltage may be applied to a first terminal of word line switch transistors that are coupled to blocks selected for erase. The first voltage may be applied to a first terminal of word line switch transistors that are coupled to blocks that are not selected for erase. The first voltage is passed to word lines in selected blocks, but is not passed to word lines in unselected blocks.
    Type: Grant
    Filed: October 26, 2011
    Date of Patent: December 23, 2014
    Assignee: SanDisk Technologies Inc.
    Inventors: Fumiaki Toyama, Masaaki Higashitani
  • Publication number: 20140369136
    Abstract: Apparatus, systems, and methods for providing high voltage to memory devices are provided. One apparatus includes a low voltage input and a two-rail level shifting. The two-rail level shifting is configured to increase the low voltage or to decrease the low voltage to an amount that is less than or equal to a ground potential based on the amount of the low voltage. A system includes a low voltage input for receiving a voltage and a two-rail level shifting coupled to the low voltage input. The two-rail level shifting is configured to increase the voltage to a positive voltage if the voltage is equal to a ground potential and decrease the voltage to a negative voltage if the voltage is greater than the ground potential. One method includes receiving a voltage, modifying the voltage to generate one of a plurality of output voltages, and providing the output voltage to a memory device.
    Type: Application
    Filed: May 23, 2014
    Publication date: December 18, 2014
    Applicant: Cypress Semiconductor Corporation
    Inventors: Ryan T. Hirose, Bogdan I. Georgescu, Leonard Vasile Gitlan, Ashish Ashok Amonkar, Gary Peter Moscaluk, John W. Tiede
  • Patent number: 8913429
    Abstract: According to one embodiment, an erase verification execution unit that makes an erase verify operation of a memory cell, on which an erase operation is performed, to be performed, a number-of-erase-verifications counting unit that counts the number of erase verifications of a memory cell on which the erase operation is performed, and a number-of-erase-verifications setting unit that sets a minimum number of erase verifications for the next time based on the current number of erase verifications counted by the number-of-erase-verifications counting unit are included.
    Type: Grant
    Filed: February 10, 2012
    Date of Patent: December 16, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Yasushi Nakajima
  • Publication number: 20140362644
    Abstract: A memory structure comprises a semiconductor strip having a multi-gate channel region, the p-type terminal region adjacent a first side of the channel region and an n-type terminal region adjacent the second side of the channel region. A plurality of word lines is arranged to cross the semiconductor strip at cross points in the channel region. The bit line is coupled to a first end of the semiconductor strip, and a reference line is coupled to a second end of the semiconductor strip. Charge storage structures are disposed between the word lines in the plurality word lines and the channel region of the semiconductor strip, whereby memory cells are disposed in series along the semiconductor strip between the bit line and the reference line. Biasing unselected word lines can be used to select n-channel or p-channel modes in a single selected cell for read, program or erase.
    Type: Application
    Filed: March 13, 2014
    Publication date: December 11, 2014
    Applicant: MACRONIX INTERNATIONAL CO., LTD.
    Inventors: Hang-Ting LUE, Wei-Chen CHEN
  • Patent number: 8908435
    Abstract: An erase process for a 3D stacked memory device controls a drain-side select gate (SGD) and a source-side select gate (SGS) of a NAND string. In one approach, SGD and SGS are driven to provide a predictable drain-to-gate voltage across the select gates while an erase voltage is applied to a bit line or source line. A more consistent gate-induced drain leakage (GIDL) at the select gates can be generated to charge up the body of the NAND string. Further, the select gate voltage can be stepped up with the erase voltage to avoid an excessive drain-to-gate voltage across the select gates which causes degradation. The step up in the select gate voltage can begin with the first erase-verify iteration of an erase operation, or at a predetermined or adaptively determined erase-verify iteration, such as based on a number of program-erase cycles.
    Type: Grant
    Filed: December 21, 2011
    Date of Patent: December 9, 2014
    Assignee: SanDisk Technologies Inc.
    Inventors: Haibo Li, Xiying Costa, Chenfeng Zhang
  • Patent number: 8908444
    Abstract: An erase operation for a 3D stacked memory device adjusts a start time of an erase period and/or a duration of the erase period for each storage element based on a position of the storage element. A voltage is applied to one or both drive ends of a NAND string to pre-charge a channel to a level which is sufficient to create gate-induced drain leakage at the select gate transistors. With timing based on a storage element's distance from the driven end, the control gate voltage is lowered to encourage tunneling of holes into a charge trapping layer in the erase period. The lowered control gate voltage results in a channel-to-control gate voltage which is sufficiently high to encourage tunneling. The duration of the erase period is also increased when the distance from the driven end is greater. As a result, a narrow erase distribution can be achieved.
    Type: Grant
    Filed: August 6, 2013
    Date of Patent: December 9, 2014
    Assignee: SanDisk Technologies Inc.
    Inventors: Xiying Costa, Seung Yu, Roy E. Scheuerlein, Haibo Li, Man L. Mui
  • Patent number: 8908453
    Abstract: Various data protection techniques are provided. In one embodiment, a memory device is provided. The memory device may initiate a security measure upon occurrence of one or more triggering events. The one or more triggering events may include receipt of a command signal. Various additional methods, devices, and systems are also provided.
    Type: Grant
    Filed: October 16, 2013
    Date of Patent: December 9, 2014
    Assignee: Round Rock Research, LLC
    Inventor: Thomas H. Kinsley
  • Patent number: 8908434
    Abstract: A FLASH memory cell includes a control gate over a floating gate over a substrate. A wall line and an erase gate each is disposed adjacent to a respective sidewall of the control gate. A first source/drain (S/D) region is disposed in the substrate and adjacent to a sidewall of the wall line. A second S/D region is disposed in the substrate and adjacent to the sidewall of the floating gate. A method of operating the FLASH memory cell includes applying a first voltage level to the control gate. A second voltage level is applied to the word line. The second voltage level is lower than the first voltage level. A third voltage level is applied to the first S/D region. A fourth voltage level is applied to the second S/D region. The fourth voltage level is higher than the third voltage level. The erase gate is electrically floating.
    Type: Grant
    Filed: February 4, 2011
    Date of Patent: December 9, 2014
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.
    Inventors: Yvonne Lin, Tien-Chun Yang
  • Patent number: 8908438
    Abstract: Flash memory devices and systems are provided. One flash memory device includes an n-channel metal oxide semiconductor field-effect transistor (nMOSFET), a silicon-oxide-nitride-oxide silicon (SONOS) transistor coupled to the nMOSFET, and an isolated p-well coupled to the nMOSFET and the SONOS transistor. A flash memory system includes an array of memory devices divided into a plurality of paired sectors, a global bit line (GBL) configured to provide high voltage to each respective sector during erase and program operations coupled to each of the plurality of sectors, and a plurality of sense amplifiers coupled between a respective pair of sectors. Methods for operating a flash memory are also provided. One method includes providing high voltage, via the GBL, to the paired sectors during erase and program operations and providing low voltage, via a local bit line, to each memory device during read operations.
    Type: Grant
    Filed: October 29, 2013
    Date of Patent: December 9, 2014
    Assignee: Cypress Semiconductor Corporation
    Inventors: Ryan Tasuo Hirose, Bogdan I. Georgescu, Ashish Ashok Amonkar, Vijay Raghavan, Cristinel Zonte, Sean B. Mulholland
  • Publication number: 20140355357
    Abstract: The present disclosure relates to a method for writing in an EEPROM memory, the method comprising steps of: storing the bits of a word to be written in first memory units, erasing a word to be modified, formed by first memory cells connected to a word line and first bit lines, reading bits stored in the memory cells of a word line WL<i>, in a first read mode and storing the bits read in second memory units, reading in a second read mode the bits stored in the memory cells of the word line, and programming each memory cell of the word line connected to a memory unit storing a bit in the programmed state of the word to be written, of an erased word or of a word comprising a bit having different states in the first and second read modes.
    Type: Application
    Filed: June 2, 2014
    Publication date: December 4, 2014
    Applicant: STMicroelectronics (Rousset) SAS
    Inventor: Francois Tailliet
  • Patent number: 8902658
    Abstract: Erasing memory cells in certain 3-D NAND charge-storage memory arrays is achieved by rapidly charging vertical conductors using Gate Induced Drain Leakage (GIDL) current generated in select transistors. When bit line voltage drops below its nominal value, select line voltage is controlled to maintain a constant voltage difference between bit line voltage and select line voltage thus maintaining a gate-drain voltage difference in select transistors that provides sufficient GIDL current for erase.
    Type: Grant
    Filed: May 21, 2014
    Date of Patent: December 2, 2014
    Assignee: SanDisk Technologies Inc.
    Inventors: Deepak Raghu, Gautam Dusija, Chris Avila, Yingda Dong, Man Mui, Pao-Ling Koh
  • Patent number: 8902671
    Abstract: A method for programming data is provided for a memory storage device having a rewritable non-volatile memory module and a buffer memory. The method includes receiving a plurality of data including a first-type data and at least one second-type data, and a size of the first-type data is smaller than a data size threshold. The method includes temporarily storing the plurality of data into the buffer memory, and programming the first-type data and at least one part of the at least one second-type data stored in the buffer memory into a physical program unit set if it is determined that the plurality of data are complied with a predetermined condition. The method includes obtaining writing statuses of the first-type data and the at least one part of the at least one second-type data at the same time.
    Type: Grant
    Filed: March 6, 2013
    Date of Patent: December 2, 2014
    Assignee: Phison Electronics Corp.
    Inventors: Hong-Lipp Ko, Kuo-Lung Lee, Teng-Chun Hsu
  • Patent number: 8902670
    Abstract: According to one embodiment, a semiconductor memory device includes memory cell arrays each including blocks. The block is unit of erase and includes string-groups. Each string-group includes strings each including a first transistor, memory cell transistors, a second transistor coupled in series. The first transistor is connected to different bit line and the second transistor is connected to same source line. The memory cell arrays are provided with different respective block address signals. The memory cell arrays are provided with different respective string address signals. Each of the block address signals specifies one block. Each of the string address signals specifies one string-group.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: December 2, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tokumasa Hara, Hiroshi Sukegawa, Toshio Fujisawa, Shirou Fujita, Masaki Unno, Masanobu Shirakawa
  • Patent number: 8897088
    Abstract: A system on chip (SoC) provides a nonvolatile memory array that is configured as n rows by m columns of bit cells. Each of the bit cells is configured to store a bit of data. There are m bit lines each coupled to a corresponding one of the m columns of bit cells. There are m write drivers each coupled to a corresponding one of the m bit lines. An AND gate is coupled to the m bit lines and has an output line coupled to an input of a test controller on the SoC. An OR gate is coupled to the m bit lines and has an output line coupled to an input of the test controller.
    Type: Grant
    Filed: January 30, 2013
    Date of Patent: November 25, 2014
    Assignee: Texas Instrument Incorporated
    Inventors: Steven Craig Bartling, Sudhanshu Khanna
  • Publication number: 20140340967
    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: June 27, 2014
    Publication date: November 20, 2014
    Inventors: Yuniarto Widjaja, John W. Cooksey, Changyuan Chen, Feng Gao, Ya-Fen Lin, Dana Lee
  • Patent number: 8891305
    Abstract: Apparatuses and methods involving accessing distributed sub-blocks of memory cells are described. In one such method, distributed sub-blocks of memory cells in a memory array are enabled to be accessed at the same time. Additional embodiments are described.
    Type: Grant
    Filed: August 21, 2012
    Date of Patent: November 18, 2014
    Assignee: Micron Technology, Inc.
    Inventor: Toru Tanzawa
  • Patent number: 8891315
    Abstract: A method of erasing a nonvolatile memory device, which includes a plurality of memory blocks each formed of a plurality of strings, includes applying an erase voltage to a well of a selected memory block of the memory blocks, each memory block including at least two dummy cells located between a string or ground selection transistor and memory cells; and applying or inducing different levels of voltages to respective gates of the at least two dummy cells.
    Type: Grant
    Filed: March 14, 2013
    Date of Patent: November 18, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: ChangHyun Lee, Byoungkeun Son
  • 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: 8891314
    Abstract: A semiconductor memory device and the operating method thereof use a low pass voltage to boost a channel of unselected cell strings during a program operation, and boost the channel of the cell string by using the GIDL phenomenon, thereby reducing a disturbance influence on the memory cells connected to the unselected cell strings due to a high pass voltage.
    Type: Grant
    Filed: September 7, 2012
    Date of Patent: November 18, 2014
    Assignee: SK Hynix Inc.
    Inventor: Kyoung Jin Park
  • Patent number: 8891316
    Abstract: Nonvolatile memory devices can include a floating gate on a substrate, with a first tunnel insulating film therebetween. A memory gate can be on the floating gate, with a blocking insulating film therebetween. A word line can be located at a first side of both the memory gate and the floating gate, with a second tunnel insulating film therebetween. The first side of the floating gate can protrude beyond the first side of the memory gate toward the word line.
    Type: Grant
    Filed: March 23, 2012
    Date of Patent: November 18, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Boyoung Seo, Yongkyu Lee, Hyucksoo Yang, Yongtae Kim, Byungsup Shim
  • Patent number: 8885419
    Abstract: A semiconductor memory device comprises a memory cell array including a plurality of memory blocks each including a plurality of pages, wherein each of the plurality of pages includes at least one flag cell indicating whether data is in a corresponding page, and a peripheral circuit configured to read data of flag cells of a selected memory block in response to an erase request and to omit an erase operation on the selected memory block based on the data of the flag cells.
    Type: Grant
    Filed: September 13, 2012
    Date of Patent: November 11, 2014
    Assignee: SK Hynix Inc.
    Inventors: Seong Hun Park, Jae Won Cha
  • Patent number: 8885420
    Abstract: Techniques are disclosed herein for erasing non-volatile storage elements. A sequence of increasing erase voltages may be applied to a substrate. The select line may be floated and many of the word lines may be held at a low voltage (e.g., close to 0V). However, the voltage applied to an edge word may be increased in magnitude relative to a previous voltage applied to the edge word line for at least a portion of the sequence of erase voltages. The edge word line could be the word line that is immediately adjacent to the select line. The increasing voltage applied to the edge word line may prevent or reduce damage to oxides between the select line and edge word line. It may also help to regulate the e-field across a tunnel oxide of memory cells on the edge word line.
    Type: Grant
    Filed: January 2, 2013
    Date of Patent: November 11, 2014
    Assignee: SanDisk Technologies Inc.
    Inventors: Ken Oowada, Deepanshu Dutta
  • Patent number: 8885412
    Abstract: An erase process for a 3D stacked memory device controls a drain-side select gate (SGD) and a source-side select gate (SGS) of a NAND string. In one approach, SGD and SGS are driven to provide a predictable drain-to-gate voltage across the select gates while an erase voltage is applied to a bit line or source line. A more consistent gate-induced drain leakage (GIDL) at the select gates can be generated to charge up the body of the NAND string. Further, the select gate voltage can be stepped up with the erase voltage to avoid an excessive drain-to-gate voltage across the select gates which causes degradation. The step up in the select gate voltage can begin with the first erase-verify iteration of an erase operation, or at a predetermined or adaptively determined erase-verify iteration, such as based on a number of program-erase cycles.
    Type: Grant
    Filed: April 16, 2014
    Date of Patent: November 11, 2014
    Assignee: SanDisk Technologies Inc.
    Inventors: Haibo Li, Xiying Costa, Chenfeng Zhang
  • Patent number: 8879323
    Abstract: An interconnection matrix consists of a plurality of semiconductor Non-Volatile Memory (NVM) forming an M×N array. Semiconductor NVM devices in the array are either programmed to a high threshold voltage state or erased to a low threshold voltage state according to a specific interconnection configuration. Applied with a gate voltage bias higher than the low threshold voltage and lower than the high threshold voltage to the control gates of the entire semiconductor NVM devices in the array, the configured interconnection network is formed. The disclosed interconnection matrix can be applied to configuring circuit routing in Integrated Circuit (IC).
    Type: Grant
    Filed: November 21, 2012
    Date of Patent: November 4, 2014
    Assignee: FlashSilicon Incorporation
    Inventor: Lee Wang
  • Patent number: 8879333
    Abstract: An erase operation for a 3D stacked memory device selectively inhibits subsets of memory cells which meet a verify condition as the erase operation progresses. As a result, the faster-erasing memory cells are less likely to be over-erased and degradation is reduced. Each subset of memory cells can be independently erased by controlling a select gate, drain (SGD) transistor line, a bit line or a word line, according to the type of subset. For a SGD line subset or a bit line subset, the SGD line or bit line, respectively, is set at a level which inhibits erase. For a word line subset, the word line voltage is floated to inhibit erase. An inhibit or uninhibit status can be maintained for each subset, and each type of subset can have a different maximum allowable number of fail bits.
    Type: Grant
    Filed: May 29, 2014
    Date of Patent: November 4, 2014
    Assignee: SanDisk Technologies Inc.
    Inventors: Xiying Costa, Haibo Li, Masaaki Higashitani, Man L Mui
  • Patent number: 8879330
    Abstract: A method of erasing a non-volatile memory (NVM) array includes determining a first number based on a temperature of the NVM array. Erase pulses of the first number are applied to the NVM array. A first verify of the NVM is performed for a first time after commencing the applying after the first number has been reached.
    Type: Grant
    Filed: April 30, 2013
    Date of Patent: November 4, 2014
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Fuchen Mu, Yanzhuo Wang
  • Patent number: 8873296
    Abstract: A control circuit is configured to execute an erasing operation on a selected cell unit in a selected memory block. In the erasing operation, the control circuit raises the voltage of the bodies of the first memory transistors included in the selected cell unit to a first voltage, sets the voltage of the bodies of the first memory transistors included in the non-selected cell unit to a second voltage lower than the first voltage, and applies a third voltage equal to or lower than the second voltage to the gates of the first memory transistors included in the selected cell unit and the non-selected cell unit.
    Type: Grant
    Filed: July 29, 2013
    Date of Patent: October 28, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kiyotaro Itagaki, Masaru Kito, Ryu Ogiwara, Hitoshi Iwai
  • Patent number: 8873302
    Abstract: An array of memory cells, in which one or more memory cells have a common doped region. Each memory cell includes a transistor with a floating gate, source and drain regions, and separate gate and drain voltage controls. Each memory cell also includes a coupling capacitor electrically coupled to and located laterally from the floating gate. In the array, first bit lines are oriented in a first direction, wherein a first bit line is coupled to drain regions of transistors that are arranged in a column. The array includes second bit lines also oriented in the first direction, wherein a second bit line is coupled to source regions of transistors that are arranged in a column. The array also includes word lines oriented in a second direction, wherein each word line is coupled to control gates of coupling capacitors that are arranged in a row.
    Type: Grant
    Filed: October 28, 2011
    Date of Patent: October 28, 2014
    Assignee: Invensas Corporation
    Inventors: David Edward Fisch, William C. Plants, Michael Curtis Parris
  • 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: 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: 8861280
    Abstract: An erase operation for a 3D stacked memory device adjusts a start time of an erase period and/or a duration of the erase period for each storage element based on a position of the storage element. A voltage is applied to one or both drive ends of a NAND string to pre-charge a channel to a level which is sufficient to create gate-induced drain leakage at the select gate transistors. With timing based on a storage element's distance from the driven end, the control gate voltage is lowered to encourage tunneling of holes into a charge trapping layer in the erase period. The lowered control gate voltage results in a channel-to-control gate voltage which is sufficiently high to encourage tunneling. The duration of the erase period is also increased when the distance from the driven end is greater. As a result, a narrow erase distribution can be achieved.
    Type: Grant
    Filed: May 16, 2014
    Date of Patent: October 14, 2014
    Assignee: SanDisk Technologies Inc.
    Inventors: Xiying Costa, Seung Yu, Roy E Scheuerlein, Haibo Li, Man L Mui
  • Patent number: 8861282
    Abstract: Techniques are provided for programming and erasing of select gate transistors in connection with the programming or erasing of a set of memory cells. In response to a program command to program memory cells, the select gate transistors are read to determine whether their Vth is below an acceptable range, in which case the select gate transistors are programmed before the memory cells. Or, a decision can be made to program the select gate transistors based on a count of program-erase cycles, whether a specified time period has elapsed and/or a temperature history of the non-volatile storage device. When an erase command is made to erase memory cells, the select gate transistors are read to determine whether their Vth is above an acceptable range. If their Vth is above the acceptable range, the select gate transistors can be erased concurrently with the erasing of the memory cells.
    Type: Grant
    Filed: January 11, 2013
    Date of Patent: October 14, 2014
    Assignee: SanDisk Technologies Inc.
    Inventors: Deepanshu Dutta, Yan Li, Masaaki Higashitani, Mohan Dunga
  • Patent number: 8854882
    Abstract: Apparatuses, systems, methods, and computer program products are disclosed for configuring storage cells. A method includes detecting a shift in a read voltage level past a read voltage threshold for a set of memory cells of a non-volatile memory medium. A method includes adjusting a read voltage threshold for the set of memory cells by an amount based at least in part on one or more characteristics of the set of memory cells in response to the shift in the read voltage level. A method includes configuring the set of memory cells to use the adjusted read voltage threshold.
    Type: Grant
    Filed: October 30, 2013
    Date of Patent: October 7, 2014
    Assignee: Intelligent Intellectual Property Holdings 2 LLC
    Inventors: John Strasser, David Flynn, Jeremy Fillingim, Robert Wood
  • Patent number: 8854879
    Abstract: A method of programming a nonvolatile memory device including multi-level cells that store multi-bit data, includes performing a pre-programming operation that programs at least some of the multi-level cells to a plurality of intermediate states which are different from an erased state, and performing a main programming operation that programs the multi-level cells to a plurality of target states corresponding to the multi-bit data. At least some of the intermediate program states have threshold voltage distributions that partially overlap each other.
    Type: Grant
    Filed: January 31, 2013
    Date of Patent: October 7, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Dong-Kyo Shim, Min-Seok Kim, Tae-Young Kim, Ki-Tae Park, Jae-Yong Jeong
  • Patent number: 8854881
    Abstract: Embodiments of the invention relate generally to semiconductors and memory technology, and more particularly, to systems, integrated circuits, and methods to implement circuits configured to compensate for parameter variations in layers of memory by adjusting access signals during memory operations. In some embodiments, memory cells are based on third dimensional memory technology. In at least some embodiments, an integrated circuit includes multiple layers of memory, a layer including sub-layers of semiconductor material. The integrated circuit also includes an access signal generator configured to generate an access signal to facilitate an access operation, and a characteristic adjuster configured to adjust the access signal for each layer in the multiple layers of memory.
    Type: Grant
    Filed: April 8, 2013
    Date of Patent: October 7, 2014
    Assignee: Unity Semiconductor Corporation
    Inventors: Christophe Chevallier, Seow Fong Lim, Chang Hua Siau
  • Publication number: 20140293708
    Abstract: Nonvolatile memory devices including three transistor unit cells are provided. The nonvolatile memory device includes a selection transistor having a first terminal and a second terminal, a first charge trap transistor electrically connected in series to the first terminal of the selection transistor, a second charge trap transistor electrically connected in series to the second terminal of the selection transistor, and a word line electrically connected to gate electrodes of the selection transistor, the first charge trap transistor and the second charge trap transistor. Related methods are also provided.
    Type: Application
    Filed: September 11, 2013
    Publication date: October 2, 2014
    Applicant: SK hynix Inc.
    Inventor: Young Joon KWON
  • Patent number: 8848455
    Abstract: According to one embodiment, a method is disclosed for manufacturing a nonvolatile memory device. The method can include forming a second stacked body, removing the second stacked body formed in a region where a first memory unit will be formed, forming a first stacked body, and removing the first stacked body formed in a region where a second memory unit will be formed. The method can include simultaneously processing the first stacked body formed in a region where the first memory unit will be formed and the second stacked body formed in a region where the second memory unit will be formed to form a memory cell of the first memory unit from the first stacked body and form a memory cell of the second memory unit from the second stacked body.
    Type: Grant
    Filed: September 20, 2011
    Date of Patent: September 30, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Kenji Noma
  • Patent number: 8848452
    Abstract: Embodiments described herein generally relate to verifying that a FLASH memory has been erased. In an embodiment, a method of erase verifying a memory column of a FLASH memory includes applying a pass gate voltage to even numbered memory transistors while applying an erase verify voltage to the odd numbered memory transistors. Applying a string current to the memory column allows a probe to determine if the string current is successfully traversing the memory column, and thus verifying that the odd numbered memory transistors were erased. The even numbered memory transistors are verified in the following cycle.
    Type: Grant
    Filed: April 4, 2013
    Date of Patent: September 30, 2014
    Assignee: Spansion LLC
    Inventor: Sameer Haddad
  • 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: 8848448
    Abstract: A semiconductor memory device and a method of operating same includes reading a number of program/erase operations stored in a program/erase number storage unit, setting a pulse width of a program voltage based on the read number of program/erase operations, and performing a program operation on memory cells using the program voltage having the set pulse width. Setting of the pulse width of the program voltage includes decreasing the pulse width of the program voltage as the number of program/erase operations increases.
    Type: Grant
    Filed: December 14, 2012
    Date of Patent: September 30, 2014
    Assignee: SK Hynix Inc.
    Inventor: Jong Soon Leem
  • 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