Tunnel Programming Patents (Class 365/185.28)
  • Patent number: 7679965
    Abstract: A memory includes a plurality of flash cells and circuitry for programming a first cell to store first data and one or more second cells to store second data. Either the circuitry itself, or a controller of the memory, or a host of the memory by executing driver code, causes the programming of the first cell to be in accordance with the second data, with at least a portion of the programming of the first cell being effected before any of the programming of the second cell(s).
    Type: Grant
    Filed: August 9, 2007
    Date of Patent: March 16, 2010
    Assignee: SanDisk IL Ltd
    Inventor: Menahem Lasser
  • Publication number: 20100061154
    Abstract: OTP Data storage die and device consisting of novel OTP (One-Time-Programming) NVM (Non-Volatile-Memory) die is disclosed. The OTP Data storage device can be used in typical host applications with standard interface protocols and file system. The novel OTP memory is a dual memory with both RAM (random access memory) capability and NAND Flash like interface. These features enable to achieve efficient management capabilities and dense array for the OTP data storage device.
    Type: Application
    Filed: September 10, 2008
    Publication date: March 11, 2010
    Applicant: Infinite Memories Ltd.
    Inventors: Eli Lusky, Yoav Yogev
  • Patent number: 7675783
    Abstract: Provided are a nonvolatile memory device and a driving method thereof. In the method of driving a nonvolatile memory device, a structural shape and position of a memory cell to be driven is determined, and then the memory cell is driven with an optimized operating condition according to a distribution of the memory cell using a determination result.
    Type: Grant
    Filed: February 22, 2008
    Date of Patent: March 9, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Ki-Tae Park, Ki-Nam Kim, Yeong-Taek Lee
  • Patent number: 7675786
    Abstract: A semiconductor memory device may include a semiconductor substrate, a control gate electrode recessed in the semiconductor substrate, a storage node layer between the control gate electrode and the semiconductor substrate, a tunneling insulating layer between the storage node layer and the semiconductor substrate, a blocking insulating layer between the storage node layer and the control gate electrode, and first and second channel regions surrounding the control gate electrode and separated by a pair of opposing separating insulating layers. A method of operating the semiconductor memory device may include programming data in the storage node layer by charge tunneling through the blocking insulating layer, thus achieving relatively high reliability and efficiency.
    Type: Grant
    Filed: September 14, 2007
    Date of Patent: March 9, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Sang-jin Park, In-jun Hwang, Jae-woong Hyun, Yoon-dong Park, Kwang-soo Seol, Sang-min Shin, Sang-moo Choi, Ju-hee Park
  • Patent number: 7675107
    Abstract: A semiconductor memory device, firstly, has both the thickness of a tunnel film and that of a top film provided thereon and configured to be in the FN tunneling region (4 nm or more). The data retention characteristics can be improved by configuring both the thickness of a tunnel film and that of a top film to have a thickness of in the FN tunneling region. Secondly, a high-concentration impurity region of a conductivity type the same as that of the substrate is provided in a substrate region arranged between assist gates provided adjacently to each other. The aforementioned high-concentration impurity region makes a depletion layer extremely thin when bias is applied to the assist gates. Hot holes generated between bands in the depletion region are injected into a charge storage region and the holes and electrons make pairs and disappear, enabling easy data erasing.
    Type: Grant
    Filed: December 27, 2005
    Date of Patent: March 9, 2010
    Assignee: Spansion LLC
    Inventor: Hiroyuki Nansei
  • Patent number: 7675787
    Abstract: A non-volatile memory array includes a semiconductor substrate having a main surface, a first source/drain region and a second source/drain region. The second source/drain region is spaced apart from the first source/drain region. A well region is disposed in a portion of the semiconductor substrate between the first source/drain region and the second source/drain region. A plurality of memory cells are disposed on the main surface above the well region. Each memory cell includes a first oxide layer formed on the main surface of the substrate, a charge storage layer disposed above the first oxide layer relative to the main surface of the semiconductor substrate and a second oxide layer disposed above the charge storage layer relative to the main surface of the semiconductor substrate. A plurality of wordlines are disposed above the second oxide layer relative to the main surface of the semiconductor substrate.
    Type: Grant
    Filed: May 19, 2008
    Date of Patent: March 9, 2010
    Assignee: MACRONIX International Co., Ltd.
    Inventor: Hsiang-Lan Lung
  • Patent number: 7672159
    Abstract: A method of operating a multi-level cell is described, wherein the cell includes a substrate of a first conductivity type, a control gate, a charge-storing layer and two S/D regions of a second conductivity type. The method includes an erasing step that injects charges of a first type into the charge-storing layer and a programming step that includes applying a first voltage to the substrate, a second voltage to both S/D regions and a third voltage to the control gate. The difference between the first and second voltages is sufficient to cause band-to-band tunneling hot holes, and the third voltage causes charges of a second type to enter the charge-storing layer. The third voltage can have 2n?1 different values, for programming the cell to a predetermined state among 2n?1 storage states.
    Type: Grant
    Filed: January 5, 2007
    Date of Patent: March 2, 2010
    Assignee: MACRONIX International Co., Ltd.
    Inventors: Ming-Chang Kuo, Chao-I Wu
  • Patent number: 7672171
    Abstract: A first plane of memory cells is formed on mesas of the array. A second plane of memory cells is formed in valleys adjacent to the mesas. The second plurality of memory cells is coupled to the first plurality of memory cells through a series connection of their source/drain regions. Wordlines couple rows of memory cells of the array. Metal shields are formed between adjacent wordlines and substantially parallel to the wordlines to shield the floating gates of adjacent cells.
    Type: Grant
    Filed: January 14, 2008
    Date of Patent: March 2, 2010
    Assignee: Micron Technology, Inc.
    Inventors: Leonard Forbes, Kie Y. Ahn
  • Patent number: 7672165
    Abstract: A NAND flash memory device incorporates a unique booster plate design. The booster plate is biased during read and program operations and the coupling to the floating gates in many cases reduces the voltage levels necessary to program and read the charge stored in the gates. The booster plate also shields against unwanted coupling between floating gates. Self boosting, local self boosting, and erase area self boosting modes used with the unique booster plate further improve read/write reliability and accuracy. A more compact and reliable memory device can hence be realized according to the present invention.
    Type: Grant
    Filed: February 14, 2008
    Date of Patent: March 2, 2010
    Assignee: SanDisk Corporation
    Inventors: Tuan D Pham, Masaaki Higashitani, Hao Fang Fang, Gerrit Jan Hemink
  • Patent number: 7672164
    Abstract: A semiconductor integrated circuit device includes first and second nonvolatile semiconductor memories. The first memory has first and second select transistors and first memory cell transistors. The first memory cell transistor has a first floating gate on a first gate insulating film and a first control gate on a first inter-gate insulating film. The second memory has a third select transistor and a second memory cell transistor. The second memory cell transistor has a second floating gate on a second gate insulating film and a second control gate on a second inter-gate insulating film. The first and second gate insulating films have the same film thickness. The first and second floating gates have the same film thickness. The first and second inter-gate insulating films have the same film thickness. The first and second control gates have the same film thickness.
    Type: Grant
    Filed: February 7, 2008
    Date of Patent: March 2, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takehiro Hasegawa, Akira Umezawa, Koji Sakui, Fumitaka Arai, Ryo Mitani
  • Patent number: 7668016
    Abstract: Non-volatile memory devices and methods of programming a non-volatile memory device in which electrons are moved between charge trap layers through a pad oxide layer are provided. The non-volatile memory devices include a charge trap layer on a semiconductor substrate and storing electrons, a pad oxide layer on the first charge trap layer, and a second trap layer on the pad oxide layer and storing electrons. In a programming mode in which data is written, the stored electrons are moved between a first position of the first charge trap layer and a first position of the second charge trap layer through the pad oxide layer or between a second position of the first charge trap layer and a second position of the second charge trap layer through the pad oxide layer.
    Type: Grant
    Filed: March 27, 2008
    Date of Patent: February 23, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jung-hun Sung, Kwang-soo Seol, Woong-chul Shin, Sang-jin Park, Sang-moo Choi
  • Patent number: 7668014
    Abstract: A non-volatile memory device, related memory system, and program method for the non-volatile memory device are disclosed. In the method, memory cells in a memory cell array are accessed through a plurality of word lines by applying a program voltage to a selected word line, wherein the selected word line is not adjacent to an outmost word line, applying a first reduced pass voltage to word lines adjacent to the selected word line, and applying a second reduced pass voltage to the outermost word lines.
    Type: Grant
    Filed: April 21, 2008
    Date of Patent: February 23, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Sang-Won Hwang
  • Publication number: 20100039868
    Abstract: An Electrically Erasable Programmable Read Only Memory (EEPROM) memory cell (FIGS. 1-2) is disclosed. The memory cell includes a sense transistor (152) having a source (110), a drain (108), and a control gate layer (156). The memory cell includes a first lightly doped region (160) having a first conductivity type and a second lightly doped region (162) having the first conductivity type. A first dielectric region is formed between the control gate layer and the first lightly doped region. A second dielectric region is formed between the control gate layer and the second lightly doped region.
    Type: Application
    Filed: July 28, 2009
    Publication date: February 18, 2010
    Inventors: Allan T. Mitchell, Harvey J. Stiegler
  • Publication number: 20100039867
    Abstract: A gated diode nonvolatile memory cell with a charge storage structure includes a diode structure with an additional gate terminal. Adjacent memory devices are electrically isolated. Example embodiments include the individual memory cell, an array of such memory cells, methods of operating the memory cell or array of memory cells, and methods of manufacturing the same.
    Type: Application
    Filed: August 15, 2008
    Publication date: February 18, 2010
    Applicant: Macronix International Co., Ltd.
    Inventors: Tien-Fan Ou, Wen-Jer Tsai, Jyun-Siang Huang
  • Publication number: 20100034028
    Abstract: In a nonvolatile semiconductor memory device having n (n is an integer of two or more) electrode films stacked and having charge storage layers provided above and below each of the electrode films, when data “0” is written by injecting electrons into the charge storage layer on a source line side of a memory cell of the number k (k is an integer of 1 to (n?1)) as counted from an end on a bit line side in a selected semiconductor pillar, positive program potential is given to the electrode film of the number 1 to k as counted from the bit line side, and 0 V is given to the electrode film of the number (k+1) to n, therewith positive potential is given to the bit line and 0 V is given to the source line.
    Type: Application
    Filed: August 5, 2009
    Publication date: February 11, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Ryota KATSUMATA, Masaru Kito, Yoshiaki Fukuzumi, Masaru Kidoh, Hiroyasu Tanaka, Megumi Ishiduki, Yosuke Komori, Hideaki Aochi
  • Patent number: 7660164
    Abstract: A method is provided, which can improve the efficiency of device design by estimating the variation of threshold voltage according to the pulse widths of applied voltage for a semiconductor device in mass product.
    Type: Grant
    Filed: December 22, 2006
    Date of Patent: February 9, 2010
    Assignee: Dongbu Electronics Co., Ltd.
    Inventor: Sang Hun Kwak
  • Patent number: 7660166
    Abstract: Data are stored in cells of a flash memory by assigning a first portion of the data to be stored in a first cell and a second portion of the data to be stored in one or more second cells. The first cell is programmed to store the first portion in accordance with the second portion. The second cell(s) is/are programmed to store the second portion. At least a portion of the programming of the first cell is effected before any of the programming of the second cell(s).
    Type: Grant
    Filed: August 9, 2007
    Date of Patent: February 9, 2010
    Assignee: Sandisk IL Ltd.
    Inventor: Menahem Lasser
  • Patent number: 7656710
    Abstract: Adaptive write operations for non-volatile memories select programming parameters according to monitored programming performance of individual memory cells. In one embodiment of the invention, programming voltage for a memory cell increases by an amount that depends on the time required to reach a predetermined voltage and then a jump in the programming voltage is added to the programming voltage required to reach the next predetermined voltage. The adaptive programming method is applied to the gate voltage of memory cells; alternatively, it can be applied to the drain voltage of memory cells along a common word line. A circuit combines the function of a program switch and drain voltage regulator, allowing independent control of drain voltage of selected memory cells for parallel and adaptive programming. Verify and adaptive read operations use variable word line voltages to provide optimal biasing of memory and reference cells during sensing.
    Type: Grant
    Filed: July 14, 2005
    Date of Patent: February 2, 2010
    Inventor: Sau Ching Wong
  • Patent number: 7656703
    Abstract: To program one or more non-volatile storage elements, a set of programming pulses are applied to at least one selected non-volatile storage element and one or more particular unselected non-volatile storage elements, for example, via a common word line. A boosting voltage is applied to other unselected non-volatile storage elements during the programming process in order to boost the channels of the unselected non-volatile storage elements so that programming will be inhibited. Each of the programming pulses has a first intermediate magnitude, a second intermediate magnitude and a third magnitude. In one embodiment, the first intermediate magnitude is similar to or the same as the boosting voltage. The second intermediate magnitude is greater than the first intermediate magnitude, but less then the third magnitude. Such an arrangement can reduce the effects of program disturb.
    Type: Grant
    Filed: May 25, 2007
    Date of Patent: February 2, 2010
    Assignee: SanDisk Corporation
    Inventors: Yingda Dong, Jeffrey W. Lutze, Dana Lee
  • Patent number: 7656704
    Abstract: A method for programming a multi-level nitride storage memory cell capable of storing different programming states corresponding to multiple different threshold voltage levels includes providing a variable resistance capable of providing a plurality of different resistance values; connecting a drain side of the nitride storage memory cell to a selected one of the plurality of resistance values that corresponds to one of the multiple threshold voltage levels; and programming the nitride storage memory cell to store one of the program states corresponding to the one of the threshold voltage levels by applying a programming voltage to the drain side through the selected resistance.
    Type: Grant
    Filed: July 20, 2006
    Date of Patent: February 2, 2010
    Assignee: Winbond Electronics Corp.
    Inventors: Po-An Chen, Yu-Kuo Yang, Tzu-Ching Chuang, Hsiu-Han Liao
  • Patent number: 7652924
    Abstract: The present invention is directed to largely reduce peak current at the time of operation of a boosting circuit provided for an EEPROM. In the erase/write operation, first, a low-frequency clock signal as a selection clock signal is input by a low-frequency clock control signal to a charge pump. After lapse of a certain period (about ? of fall time), a high-frequency clock signal having a frequency higher than that of the low-frequency clock signal is output by a high-frequency clock control signal and is input as the selection clock signal to the charge pump to boost a voltage to a predetermined voltage level. In such a manner, while suppressing the peak of consumption current, the fall time of the boosted voltage can be shortened.
    Type: Grant
    Filed: July 11, 2008
    Date of Patent: January 26, 2010
    Assignee: Renesas Technology Corp.
    Inventors: Yoshiki Kawajiri, Masaaki Terasawa, Takanori Yamazoe
  • Patent number: 7652917
    Abstract: In a data program/erase device of a nonvolatile memory cell, data are re-written by means of an FN tunnel current of an entire channel surface. In a buried n-well of a semiconductor substrate in a flash memory formation region, p wells are placed in the form isolated from each other. In each of the p wells, a capacitor portion, a capacitor portion for programming/erasing data and an MIS•FET for reading data are placed. In the capacitor portion for programming/erasing data, rewriting (programming and erasing) of data is performed by means of an FN tunnel current of an entire channel surface.
    Type: Grant
    Filed: October 29, 2008
    Date of Patent: January 26, 2010
    Assignee: Renesas Technology Corp.
    Inventors: Yasushi Oka, Kazuyoshi Shiba
  • Patent number: 7652925
    Abstract: A method of programming a plurality of memory cells in a flash memory device from a first state to a second state includes verifying the plurality of memory cells using a verify voltage having a level increased according to an increase in a program loop number; and programming the plurality of memory cells using a program voltage having an increment decreased according to an increase in the program loop number, wherein the verifying and programming steps constitute a program loop, the program loop being terminated at a point in time when a level of the verify voltage reaches to a voltage range of the second state.
    Type: Grant
    Filed: June 24, 2008
    Date of Patent: January 26, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Sang-Pil Sim
  • Patent number: 7652923
    Abstract: A memory applicable to an embedded memory is provided. The memory includes a substrate, a gate, a charge-trapping gate dielectric layer, a source, and a drain. The gate is disposed above the substrate. The charge-trapping gate dielectric layer is disposed between the gate and the substrate. The source and the drain are disposed in the substrate beside the gate respectively.
    Type: Grant
    Filed: February 2, 2007
    Date of Patent: January 26, 2010
    Assignee: MACRONIX International Co., Ltd.
    Inventor: Chao-I Wu
  • Publication number: 20100014359
    Abstract: An operating method of a non-volatile memory adapted for a non-volatile memory disposed on an SOI substrate including a first conductive type silicon body layer is provided. The non-volatile memory includes a gate, a charge storage structure, a second conductive type drain region, and a second conductive type source region. In operating such a non-volatile memory, voltages are applied to the gate, the second conductive type drain region, the second conductive type source region and the first conductive type silicon body layer beneath the gate, to inject electrons or holes in to the charge storage structure or evacuate the electrons from the charge storage structure by a method selected from a group consisting of channel hot carrier injection, source side injection, band-to-band tunnelling hot carrier injection and Fowler-Nordheim (F-N) tunnelling.
    Type: Application
    Filed: September 24, 2009
    Publication date: January 21, 2010
    Applicant: eMemory Technology Inc.
    Inventors: Hsin-Ming Chen, Hai-Ming Lee, Shih-Jye Shen, Ching-Hsiang Hsu
  • Publication number: 20100014358
    Abstract: A method of programming a nonvolatile memory device. The method may include pre-programming one memory cell among a plurality of memory cells by storing data in a first data storage layer using a first program voltage applied to one word line corresponding to the one memory cell among the plurality of memory cells; and while pre-programming other memory cells among the plurality of memory cells, background-programming the pre-programmed memory cell by moving the stored data to a second data storage layer using a second program voltage that is higher than the first program voltage applied to the word line of the pre-programmed memory cell.
    Type: Application
    Filed: February 9, 2009
    Publication date: January 21, 2010
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventor: Dong-Il BAE
  • Publication number: 20100014348
    Abstract: The invention provides circuits, systems, and methods for programming a floating gate. A floating gate tunneling device is used with an analog comparing device in a circuit having a floating reference node and an offset-mitigating feedback loop for iteratively programming a floating gate, or multiple floating gates.
    Type: Application
    Filed: January 30, 2009
    Publication date: January 21, 2010
    Inventors: Ross E. Teggatz, Wayne T. Chen, Brett Smith, Eric Blackall
  • Patent number: 7649771
    Abstract: The present invention provides a method for decreasing program disturb in memory cells, comprising: finding an initial programming condition that ensures programming memory cell normally; selecting two parameters from the initial programming condition as variables for a program disturb test; performing the program disturb test to the memory cell for at least two combined values of the variables; obtaining a programming condition with minimum program disturb based on the result of the program disturb test; and applying the programming condition with minimum program disturb as the programming condition for memory cell. The method according to the present invention can minimize the program disturb in memory cells and can be performed easily.
    Type: Grant
    Filed: October 19, 2007
    Date of Patent: January 19, 2010
    Assignee: Semiconductor Manufacturing International (Shanghai) Corporation
    Inventors: Kenneth Miu, Leong Seng Tan, Can Zhong, Jianchang Liu
  • Publication number: 20100008153
    Abstract: A method for programming a mixed nonvolatile memory array having a plurality of mixed memory cells, wherein each mixed memory cell includes a depletion mode memory cell and an enhanced mode memory cell. The method comprises steps of programming the enhanced mode memory cell in a way of channel hot carrier and programming the depletion mode memory cell in a way of band-to-band tunneling hot carrier.
    Type: Application
    Filed: September 17, 2009
    Publication date: January 14, 2010
    Applicant: MACRONIX INTERNATIONAL CO., LTD.
    Inventors: Hao-Ming Lien, Ming-Hsiu Lee
  • Patent number: 7646647
    Abstract: An electronic circuit arrangement includes at least one memory element in which at least two electrical quantities can be stored. A switching unit is electrically connected to the memory element and has at least one first circuit path and a second circuit path. A storage unit has a first partial storage unit and a second partial storage unit. Each partial storage unit is set up for storing at least one electrical quantity. The switching unit is set up in such a way that it can sequentially pass a first one of the at least two electrical quantities along the first circuit path to the first partial storage unit and a second one of the at least two electrical quantities along the second circuit path to the second partial storage unit.
    Type: Grant
    Filed: October 4, 2006
    Date of Patent: January 12, 2010
    Assignees: Qimonda AG, Qimonda Flash GmbH & Co. KG
    Inventors: Thomas Kern, Thomas Mikolajick, Jan-Malte Schley
  • Patent number: 7646637
    Abstract: A nonvolatile memory with a modified channel region interface, such as a raised source and drain or a recessed channel region is included.
    Type: Grant
    Filed: July 9, 2007
    Date of Patent: January 12, 2010
    Assignee: Macronix International Co., Ltd.
    Inventor: Yi Ying Liao
  • Patent number: 7643349
    Abstract: A method for operating a dielectric charge trapping memory cell as described herein includes applying an initial voltage from the gate to the substrate of the memory cell for a predetermined period of time to reduce the threshold voltage of the memory cell. The method includes applying a sequence of voltages from the gate to the substrate of the memory cell to further reduce the threshold voltage of the memory cell, wherein a subsequent voltage in the sequence of voltages has a lower magnitude from the gate to the substrate than that of a preceding voltage in the sequence of voltages.
    Type: Grant
    Filed: March 20, 2008
    Date of Patent: January 5, 2010
    Assignee: Macronix International Co., Ltd.
    Inventor: Hang-Ting Lue
  • Patent number: 7639539
    Abstract: A method and an apparatus for programming data of memory cells considering coupling are provided. The method includes: calculating a change of a threshold voltage based on source data of the memory cells; converting source data which will be programmed based on the calculated change of the threshold voltage; and programming the converted source data.
    Type: Grant
    Filed: October 3, 2007
    Date of Patent: December 29, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Kyoung Lae Cho, Jun Jin Kong, Young Hwan Lee, Nam Phil Jo, Sung Chung Park, Seung-Hwan Song
  • Patent number: 7639524
    Abstract: A memory device may include a channel including at least one carbon nanotube. A source and a drain may be arranged at opposing ends of the channel and may contact different parts of the channel. A first storage node may be formed under the channel, and a second storage node may be formed on the channel. A first gate electrode may be formed under the first storage node and a second gate electrode may be formed on the second storage node.
    Type: Grant
    Filed: January 20, 2006
    Date of Patent: December 29, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Dong-Hun Kang, Jeong-Hee Han, Wan-Jun Park, Won-Joo Kim, Jae-Woong Hyun
  • Patent number: 7639537
    Abstract: A method for writing data in a non volatile memory unit having memory pages includes a predetermined number of memory cells storing a memory word being a predetermined sequence of digital values. An erase operation erases the memory words in the memory page, setting the predetermined sequence of digital values to a sequence of complementary values. A program operation stores in the memory cell a word and sets a sequence of a word to be stored. For the memory cells of the memory page, the memory word is compared with the word to be stored. A positive check is returned if complementary values of the sequence correspond to complementary values of the predetermined sequence. If the check is negative, the erase operation is executed. The memory word is compared with the word to be stored and the program operation is executed if the word to be stored is different.
    Type: Grant
    Filed: August 1, 2008
    Date of Patent: December 29, 2009
    Assignee: Incard S.A.
    Inventors: Paolo Sepe, Carlo Cimino, Maria Chichierchia
  • Publication number: 20090316480
    Abstract: Methods of storing multiple data-bits in a non-volatile memory cell are carried out by trapping carriers in a composite trapping layer formed over a tunnel insulator layer. The composite trapping layer contains a plurality of band engineered sub-layers providing a plurality of charge trapping layers.
    Type: Application
    Filed: August 25, 2009
    Publication date: December 24, 2009
    Inventor: Arup Bhattacharyya
  • Patent number: 7636260
    Abstract: A method for controlling non-volatile storage having individually controllable shield plates between storage elements. The shield plates are formed by depositing a conductive material such as doped polysilicon between storage elements and their associated word lines, and providing contacts for the shield plates. The shield plates reduce electromagnetic coupling between floating gates of the storage elements, and can be used to optimize programming, read and erase operations. The shield plates provide a field induced conductivity between storage elements in a NAND string during a sense operation so that source/drain implants are not needed in the substrate. Alternating high and low voltages are applied to the shield plates, or a common voltage is applied to the shield plates.
    Type: Grant
    Filed: June 25, 2007
    Date of Patent: December 22, 2009
    Assignee: SanDisk Corporation
    Inventor: Masaaki Higashitani
  • Patent number: 7636257
    Abstract: Methods of operating non-volatile memory devices are described. The memory devices comprise memory cells having an n-type semiconductor substrate and p-type source and drain regions disposed below a surface of the substrate and separated by a channel region. A tunneling dielectric layer is disposed above the channel region. A charge storage layer is disposed above the tunneling dielectric layer. An upper insulating layer is disposed above the charge storage layer, and a gate is disposed above the upper insulating multi-layer structure. A positive bias is applied to a word lines of the memory device in a selected memory cell and a negative bias is applied to a bit line in the selected cell.
    Type: Grant
    Filed: May 4, 2006
    Date of Patent: December 22, 2009
    Assignee: Macronix International Co., Ltd.
    Inventor: Hang-Ting Lue
  • Patent number: 7633807
    Abstract: The process for programming a set of memory cells is improved by adapting the programming process based on behavior of the memory cells. For example, a set of program pulses is applied to the word line for a set of flash memory cells. A determination is made as to which memory cells are easier to program and which memory cells are harder to program. Bit line voltages (or other parameters) can be adjusted based on the determination of which memory cells are easier to program and which memory cells are harder to program. The programming process will then continue with the adjusted bit line voltages (or other parameters).
    Type: Grant
    Filed: January 17, 2007
    Date of Patent: December 15, 2009
    Assignee: SanDisk Corporation
    Inventors: Jian Chen, Jeffrey W. Lutze, Yan Li, Daniel C. Guterman, Tomoharu Tanaka
  • Patent number: 7633811
    Abstract: A non-volatile memory system including an array of cells, each having an access transistor and a capacitor sharing a floating gate. The access transistors in each row are fabricated in separate well regions, which are independently biased. Within each row, the source of each access transistor is coupled to a corresponding virtual ground line, and each capacitor structure is coupled to a corresponding word line. Alternately, the source of each access transistor in a column is coupled to a corresponding virtual ground line. Within each column, the drain of each access transistor is coupled to a corresponding bit line. Select memory cells in each row are programmed by band-to-band tunneling. Bit line biasing prevents programming of non-selected cells of the row. Programming is prevented in non-selected rows by controlling the well region voltages of these rows. Sector erase operations are implemented by Fowler-Nordheim tunneling.
    Type: Grant
    Filed: January 28, 2008
    Date of Patent: December 15, 2009
    Assignee: MoSys, Inc.
    Inventors: Gang-feng Fang, Wingyu Leung
  • Patent number: 7633810
    Abstract: A non-volatile memory system including an array of cells, each having an access transistor and a capacitor sharing a floating gate. The access transistors in each row are fabricated in separate well regions, which are independently biased. Within each row, the source of each access transistor is coupled to a corresponding virtual ground line, and each capacitor structure is coupled to a corresponding word line. Alternately, the source of each access transistor in a column is coupled to a corresponding virtual ground line. Within each column, the drain of each access transistor is coupled to a corresponding bit line. Select memory cells in each row are programmed by band-to-band tunneling. Bit line biasing prevents programming of non-selected cells of the row. Programming is prevented in non-selected rows by controlling the well region voltages of these rows. Sector erase operations are implemented by Fowler-Nordheim tunneling.
    Type: Grant
    Filed: January 28, 2008
    Date of Patent: December 15, 2009
    Assignee: MoSys, Inc.
    Inventors: Gang-feng Fang, Wingyu Leung
  • Patent number: 7633812
    Abstract: A system is disclosed for programming non-volatile storage that improves performance by setting the starting programming voltage to a first level for fresh parts and adjusting the starting programming voltage as the memory is cycled. For example, the system programs a set of non-volatile storage elements during a first period using an increasing program signal with a first initial value and subsequently programs the set of non-volatile storage elements during a second period using an increasing program signal with a second initial value, where the second period is subsequent to the first period and the second initial value is different than the first initial value.
    Type: Grant
    Filed: January 23, 2008
    Date of Patent: December 15, 2009
    Assignee: SanDisk Corporation
    Inventor: Jeffrey Lutze
  • Patent number: 7630254
    Abstract: A system is disclosed for programming non-volatile storage that improves performance by setting the starting programming voltage to a first level for fresh parts and adjusting the starting programming voltage as the memory is cycled. For example, the system programs a set of non-volatile storage elements during a first period using an increasing program signal with a first initial value and subsequently programs the set of non-volatile storage elements during a second period using an increasing program signal with a second initial value, where the second period is subsequent to the first period and the second initial value is different than the first initial value.
    Type: Grant
    Filed: January 23, 2008
    Date of Patent: December 8, 2009
    Assignee: SanDisk Corporation
    Inventor: Jeffrey Lutze
  • Patent number: 7630253
    Abstract: A flash memory system configured in accordance with an example embodiment of the invention employs a virtual ground array architecture. During programming operations, target memory cells are biased with a positive source bias voltage to reduce or eliminate leakage current that might otherwise conduct through the target memory cells. A positive source bias voltage may also be applied to target memory cells during verification operations (program verify, soft program verify, erase verify) to reduce or eliminate leakage current that might otherwise introduce errors in the verification operations.
    Type: Grant
    Filed: April 5, 2006
    Date of Patent: December 8, 2009
    Assignee: Spansion LLC
    Inventors: Ashot Melik-Martirosian, Ed Runnion, Mark Randolph, Meng Ding
  • Patent number: 7626864
    Abstract: Nonvolatile memory cells and array are provided. The memory cell comprises a body, a source, a drain, and a charge storage region. The body comprises an n-type conductivity and is formed in a well of the n-type conductivity. The source and the drain have p-type conductivity and are formed in the well with a channel of the body defined therebetween. The charge storage region is disposed over and insulated from the channel by a channel insulator. Each cell further comprises a bias setting having a source voltage applied to the source, a well voltage applied to the well, and a drain voltage applied to the drain. A bias configuration for an erase operation of the memory cell is further provided, wherein the source voltage is sufficiently more negative with respect to the well voltage and is sufficiently more positive with respect to the drain voltage to inject hot holes onto the charge storage region. The cells can be arranged in row and column to form memory arrays and memory device.
    Type: Grant
    Filed: April 26, 2006
    Date of Patent: December 1, 2009
    Inventor: Chih-Hsin Wang
  • Patent number: 7623387
    Abstract: Non-volatile storage with reduced program disturb is provided by boosting unselected NAND strings in an array so that a source side channel, on a source side of a selected word line, is boosted before a drain side channel, on a drain side of the selected word line. In one approach, a first boost mode is used when the selected word line is a lower or intermediate word line. In the first boost mode, boosting of the source and drain side channels is initiated concurrently. A second boost mode is used when the selected word line is a higher word line. In the second boost mode, boosting of the source side channel occurs early relative to the boosting of the drain side channel. Either boost mode include an isolation voltage which tends to isolate the source and drain side channels from one another.
    Type: Grant
    Filed: December 12, 2006
    Date of Patent: November 24, 2009
    Assignee: SanDisk Corporation
    Inventors: Yingda Dong, Jeffrey W. Lutze
  • Patent number: 7623389
    Abstract: System for programming a selected non-volatile memory cell in a memory array having a gate node coupled to a wordline WL(n) and a drain node connected to a selected bitline by injecting hot carriers from a drain region of an injecting memory cell having a gate node coupled to a next neighbor wordline WL(n?1) into a floating gate of the selected non-volatile memory cell on the wordline WL(n).
    Type: Grant
    Filed: December 21, 2006
    Date of Patent: November 24, 2009
    Assignee: SanDisk Corporation
    Inventors: Dana Lee, Jeffrey Lutze
  • Patent number: 7623372
    Abstract: A nonvolatile semiconductor memory according to the invention includes a memory cell array comprised of a multivalued memory cell for storing data on a plurality of pages, a data processing circuit for carrying out a read operation for reading data from the memory cell array and a programming operation for writing the data to the memory cell array on a page unit, and a control circuit for controlling an operation of the data processing circuit, the control circuit changing an assignment of data corresponding to a threshold voltage distribution of the multivalued memory cell depending on order of a page over which the programming operation is to be carried out in such a manner that the programming operation is executed by a transition of a threshold voltage of the multivalued memory cell in a positive direction.
    Type: Grant
    Filed: November 7, 2006
    Date of Patent: November 24, 2009
    Assignee: Panasonic Corporation
    Inventor: Kazuyuki Kouno
  • Patent number: 7623386
    Abstract: Program disturb is reduced in non-volatile storage by boosting unselected NAND strings in an array so that a source side channel, on a source side of a selected word line, is boosted before a drain side channel, on a drain side of the selected word line. In one approach, a first boost mode is used when the selected word line is a lower or intermediate word line. In the first boost mode, boosting of the source and drain side channels is initiated concurrently. A second boost mode is used when the selected word line is a higher word line. In the second boost mode, boosting of the source side channel occurs early relative to the boosting of the drain side channel. Either boost mode include an isolation voltage which tends to isolate the source and drain side channels from one another.
    Type: Grant
    Filed: December 12, 2006
    Date of Patent: November 24, 2009
    Assignee: SanDisk Corporation
    Inventors: Yingda Dong, Jeffrey W. Lutze
  • Patent number: 7623385
    Abstract: Provided is a method of reading a flash memory device for depressing read disturb. According to the method, a first voltage is applied to a gate of the drain select transistor to turn on the drain select transistor, and a read voltage is applied to a gate of a selected transistor among the plurality of memory cells. Then, a pass voltage is applied to gates of unselected transistors among the plurality of memory cells. Furthermore, when the pass voltage is applied, a first pass voltage is applied and then a second pass voltage is applied after an elapse of a predetermined time following the applying of the first pass voltage. The second pass voltage has a level different from that of the first pass voltage.
    Type: Grant
    Filed: December 27, 2007
    Date of Patent: November 24, 2009
    Assignee: Hynix Semiconductor Inc.
    Inventors: Nam Kyeong Kim, Ju Yeab Lee, Keum Hwan Noh