Weak Inversion Injection Patents (Class 365/185.15)
  • Publication number: 20090316484
    Abstract: Disclosed is a semiconductor storage device comprising a semiconductor substrate, a first and a second impurity diffusion layer formed in the semiconductor substrate, a gate insulating film formed on the semiconductor substrate, and a first gate electrode formed on the semiconductor substrate via the gate insulating film. The gate insulating film has a nitrogen-containing silicon oxide film inside, and a silicon oxide film is so arranged on both sides of the nitrogen-containing silicon oxide film as to sandwich the nitrogen-containing silicon oxide film. In addition, the nitrogen composition in the nitrogen-containing silicon oxide film is increased from the semiconductor substrate side to the first gate electrode side.
    Type: Application
    Filed: December 1, 2006
    Publication date: December 24, 2009
    Inventors: Hiroshi Sunamura, Kouji Masuzaki, Masayuki Terai
  • Publication number: 20090296474
    Abstract: The present invention describes a uniform program method and a uniform erase method of a charge trapping memory by employing a substrate transient hot electron technique for programming, and a substrate transient hot hole technique for erasing, which emulate an FN tunneling method for NAND memory operation. The methods of the present invention are applicable to a wide variety of charge trapping memories including n-channel or p-channel SONOS types of memories and floating gate (FG) type memories. the programming of the charge trapping memory is conducted using a substrate transient hot electron injection in which a body bias voltage Vb has a short pulse width and a gate bias voltage Vg has a pulse width that is sufficient to move electrons from a channel region to a charge trapping structure.
    Type: Application
    Filed: August 10, 2009
    Publication date: December 3, 2009
    Applicant: Macronix International Co., Ltd.
    Inventors: TZU HSUAN HSU, Chao-I Wu, Kuang Yeu Hsieh, Ya-Chin King
  • Patent number: 7626863
    Abstract: A memory system includes memory cells arranged in sectors. A decoder corresponding to a sector disables memory cells having a defective top gate. The decoder may include a low voltage or high voltage latch for the disabling. A top gate handling algorithm is included. The memory system may include dynamic top gate coupling. A programming algorithm and waveforms with top gate handling is included.
    Type: Grant
    Filed: February 16, 2007
    Date of Patent: December 1, 2009
    Assignee: Silicon Storage Technology, Inc.
    Inventors: Hieu Van Tran, Hung Quoc Nguyen, Anh Ly, Sheng-Hsiung Hsueh, Sang Thanh Nguyen, Loc B. Hoang, Steve Choi, Thuan T. Vu
  • Patent number: 7619924
    Abstract: A device for reading out memory information storable in a memory has an integrator and a comparator. The memory provides, in a hold phase, a leakage current, and in a readout phase, a readout current. The readout current is dependent on the stored memory information. The integrator is adapted to integrate a quantity derived from the leakage current during the hold phase, and to provide a leakage voltage corresponding to an integrated leakage current. The integrator is further adapted to integrate a quantity derived from the readout current during the readout phase, and to provide a readout voltage corresponding to an integrated readout current. The comparator may compare the leakage voltage to the readout voltage and provide, in dependence on the comparison, a readout value corresponding to the memory information.
    Type: Grant
    Filed: August 29, 2007
    Date of Patent: November 17, 2009
    Assignee: Infineon Technologies AG
    Inventors: Michael Bollu, Michael Bernhard Sommer
  • Patent number: 7595532
    Abstract: A semiconductor memory device includes a semiconductor substrate including an insulating layer, a charge storage region of a first conductivity type on the insulating layer, and an insulating film on the insulating layer and surrounding the charge storage region. A body region of the first conductivity type is on an upper surface of the charge storage region, and a gate stack including a gate electrode and a gate insulating film is on the body region. A source region and a drain region of a second conductivity type are on opposite sides of the body region. The charge storage region extends further towards the semiconductor substrate than the source region and/or the drain region. Methods of forming semiconductor memory devices are also disclosed.
    Type: Grant
    Filed: January 3, 2007
    Date of Patent: September 29, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Ki-Whan Song, Chang-Hyun Kim
  • Patent number: 7596042
    Abstract: One package contains a plurality of memory chips. Each memory chip has an I/O terminal which generates a busy signal. The busy signal enables a busy state when a power supply voltage value reaches a specified and guaranteed range after a power-on sequence. The busy signal maintains the busy state until completion of initialization operations for the plurality of memory chips. The busy signal releases the busy state after completion of all initialization operations for the plurality of memory chips.
    Type: Grant
    Filed: October 2, 2007
    Date of Patent: September 29, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Nakamura, Kenichi Imamiya, Ken Takeuchi
  • Patent number: 7580295
    Abstract: A semiconductor memory device comprises a memory cell array comprising memory cells of a first type. The memory cell array performs write and read operations in response to signals designed for the operation of a memory cell array comprising memory cells of a type other than the first type.
    Type: Grant
    Filed: September 5, 2007
    Date of Patent: August 25, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Kwang-jin Lee, Woo-yeong Cho, Hye-jin Kim
  • Patent number: 7580293
    Abstract: A programmable non-volatile semiconductor memory device includes a select gate 3, arranged in a first region on a substrate, a floating gate 6 arranged in a second region neighboring to the first region, a first diffusion region 7 provided in a third region neighboring to the second region, a control gate 11 arranged on the floating gate 6, and a driving circuit 22 adapted for controlling voltages applied to the substrate 1 (well 1a), select gate 3, first diffusion region 7 and control gate 11. The driving circuit performs control so that, during erasure operation, voltages applied to select gate 3 and the control gate 11 are negative, with the remaining voltage, applied to the substrate 1 (or well 1a), being positive. The device permits erasure operation at a lower voltage.
    Type: Grant
    Filed: January 31, 2007
    Date of Patent: August 25, 2009
    Assignee: NEC Electronics Corporation
    Inventors: Kohji Kanamori, Kenichi Kuboyama
  • Patent number: 7567458
    Abstract: A memory system includes memory cells arranged in sectors. A decoder corresponding to a sector disables memory cells having a defective top gate. The decoder may include a low voltage or high voltage latch for the disabling. A top gate handling algorithm is included. The memory system may include dynamic top gate coupling. A programming algorithm and waveforms with top gate handling is included.
    Type: Grant
    Filed: September 26, 2005
    Date of Patent: July 28, 2009
    Assignee: Silicon Storage Technology, Inc.
    Inventors: Hieu Van Tran, Hung Quoc Nguyen, Anh Ly, Sheng-Hsiung Hsueh, Sang Thanh Nguyen, Loc B. Hoang, Steve Choi, Thuan T. Vu
  • Publication number: 20090168531
    Abstract: A memory structure includes a first memory cell and a second memory cell located at an identical bit line and adjacent to the first memory cell. Each memory cell includes a substrate, a source, a drain, a charge storage device, and a gate. A method for programming the memory structure includes respectively providing a first gate biasing voltage and a second gate biasing voltage to the first memory cell and the second memory cell, boosting the absolute value of a channel voltage of the first memory cell to generate electron and hole pairs at the drain of the second memory cell through gate-induced drain leakage or band-to-band tunneling, and injecting the electron of the generated electron and hole pairs into the charge storage device of the first memory cell to program the first memory cell.
    Type: Application
    Filed: June 24, 2008
    Publication date: July 2, 2009
    Inventors: Riichiro Shirota, Ching-Hsiang Hsu, Cheng-Jye Liu
  • Patent number: 7551493
    Abstract: A data processing device which selects either emission of electrons from a nonvolatile memory cell or injection of electrons into it for each bit. A memory array includes a plurality of nonvolatile memory cells each having a pair of a first MOS transistor and a second MOS transistor where the first transistor has a charge retention layer and a memory gate and is used for data storage and the second transistor has a control gate and selectively connects the first transistor to a bit line. When negative voltage is applied to a memory gate, electrons held by a charge retention layer are emitted through hot carriers generated in a nonvolatile memory cell channel region for erasing; and when positive voltage is applied to the memory gate, electrons are injected into the charge retention layer through hot carriers generated in the nonvolatile memory cell channel region for writing and controls the generation and suppression of hot carriers by means of bit line voltage on each bit line.
    Type: Grant
    Filed: June 21, 2007
    Date of Patent: June 23, 2009
    Assignee: Renesas Technology Corp.
    Inventors: Akira Kato, Toshihiro Tanaka, Takashi Yamaki
  • Publication number: 20090154246
    Abstract: Systems and methods that facilitate improved programming memory cells in a nonvolatile memory (e.g., flash memory) are presented. An optimized voltage component can facilitate supplying respective voltages to a source, drain, and gate associated with a memory cell during operations, such as programming operations. The optimized voltage component can facilitate supplying a predetermined source bitline voltage to a memory cell during programming of the cell to facilitate reducing leakage currents associated with the bitlines, which can improve programming of the memory cell, and to facilitate reducing the programming current, which can result in power efficient programming and improved programming speed.
    Type: Application
    Filed: December 13, 2007
    Publication date: June 18, 2009
    Applicant: SPANSION LLC
    Inventors: Zhizheng Liu, An Chen, Wei Zheng, Kuo-Tung Chang, Sung-Yong Chung, Gulzar Ahmed Kathawala, Ashot Melik-Martirosian
  • Publication number: 20090147577
    Abstract: The invention concerns semiconductor latches capable of memorizing any programmed information even after power supply has been removed. Used is a 0.6 m BiCMOS EPROM process but it is applicable in any other process having hot electron injection devices like EPROM, Flash EEPROM.
    Type: Application
    Filed: December 10, 2004
    Publication date: June 11, 2009
    Inventors: Valeri Dimitrov Ivanov, Hartmut Liebing
  • Patent number: 7539065
    Abstract: A non-volatile memory having a gate structure, a pair of storage units and two assist gates is provided. The gate structure is disposed on the substrate. The storage units are disposed on the sidewalls of the gate structure. The assist gates are disposed on the respective sides of the gate structure and adjacent to the storage units. Each assist gate is shared between two adjacent memory cells. The gate structure, the storage units and the assist gates are electrically isolated from one another.
    Type: Grant
    Filed: October 31, 2007
    Date of Patent: May 26, 2009
    Assignee: MACRONIX International Co., Ltd.
    Inventors: Cheng-Hsing Hsu, Hao-Ming Lien
  • Patent number: 7501677
    Abstract: A SONOS memory cell, formed within a semiconductor substrate, includes a bottom dielectric disposed on the semiconductor substrate, a charge trapping material disposed on the bottom dielectric, and a top dielectric disposed on the charge trapping material. Furthermore, the SONOS memory cell includes a word-line gate structure disposed on the top dielectric and at least one bit-line gate for inducing at least one inversion bit-line within the semiconductor substrate.
    Type: Grant
    Filed: November 10, 2006
    Date of Patent: March 10, 2009
    Assignee: Spansion LLC
    Inventors: Hidehiko Shiraiwa, Jaeyong Park, Satoshi Torii, Hideki Arakawa, Masaru Yano
  • Publication number: 20090046508
    Abstract: A method is provided for programming a memory cell of an electrically erasable programmable read only memory. The memory cell is fabricated on a substrate and comprises a source region, a drain region, a floating gate, and a control gate. The memory cell has a threshold voltage selectively configurable into one of at least three programming states. The method includes generating a drain current between the drain region and the source region by applying a drain-to-source bias voltage between the drain region and the source region. The method further includes injecting hot electrons from the drain current to the floating gate by applying a gate voltage to the control gate. A selected threshold voltage for the memory cell corresponding to a selected one of the programming states is generated by applying a selected constant drain-to-source bias voltage and a selected gate voltage.
    Type: Application
    Filed: August 1, 2006
    Publication date: February 19, 2009
    Inventors: Chun Chen, Kirk D. Prall
  • Publication number: 20090027967
    Abstract: A memory system includes a flash memory device and a memory controller for controlling the flash memory device. The flash memory device includes a cell string and a selection transistor connected in series to the cell string. The cell string includes multiple series-connected memory cells. The selection transistor has the same structure as a memory cell of the series-connected memory cells, and is programmed through channel hot electron injection.
    Type: Application
    Filed: July 18, 2008
    Publication date: January 29, 2009
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventor: Chang-hyun LEE
  • Patent number: 7471564
    Abstract: Methods of manufacturing a nitride trapping EEPROM flash memory are described where each memory cell uses Si-Fin to form a nitride trapping EEPROM flash cell in which the source region and drain region are undoped. Each adjacent poly-gate to a selected poly-gate in a row of nitride trapping memory cells is used to produce the inversion region that acts as a source region or a drain region for transferring of a required voltage, which conserves the density of a memory cell given that the source region and the drain region for each memory cell are not doped. The flash memory includes a plurality of polysilicon layers intersecting with a plurality of Si-Fin layers.
    Type: Grant
    Filed: May 7, 2008
    Date of Patent: December 30, 2008
    Assignee: Macronix International Co., Ltd.
    Inventors: Chia-Lun Hsu, Mu-Yi Liu
  • Publication number: 20080304320
    Abstract: A method of programming a memory cell is described. The memory cell includes a gate with a charge trapping layer isolated from a substrate for storing data with a first region and a second region separated from the first region. The method of programming the memory cell includes applying a first voltage arrangement with a first gate voltage for programming the first region and applying a second voltage arrangement with a second gate voltage for programming the second region. The first gate voltage is greater than the second gate voltage.
    Type: Application
    Filed: August 18, 2008
    Publication date: December 11, 2008
    Applicant: MACRONIX International Co., Ltd.
    Inventor: Chao-I Wu
  • Patent number: 7463523
    Abstract: A semiconductor memory device includes a semiconductor layer; a source layer provided in the semiconductor layer; a drain layer provided in the semiconductor layer; a body region provided in the semiconductor layer between the source layer and the drain layer; a gate insulation film provided on the body region; and a gate electrode provided on the gate insulation film, wherein data are written or read out by accumulating electric charge in the body region or releasing electric charge from the body region, and wherein a difference between the potential VSR of the source layer in a data-retaining period and the potential VGR of the gate electrode in the data-retaining period is smaller than a difference between the potential VSW of the source layer in a data write period and the potential VGR.
    Type: Grant
    Filed: September 28, 2005
    Date of Patent: December 9, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Tomoaki Shino
  • Publication number: 20080273387
    Abstract: A hot electron (BBHE) is generated close to a drain by tunneling between bands, and bit data writing is performed by injecting the hot electron into a charge storage layer. When Vg is a gate voltage, Vsub is a cell well voltage, Vs is a source voltage and Vd is a drain voltage, a relation of Vg>Vsub>Vs>Vd is satisfied, Vg?Vd is a value of a potential difference required for generating a tunnel current between the bands or higher, and Vsub?Vd is substantially equivalent to a barrier potential of the tunnel insulating film or higher.
    Type: Application
    Filed: November 1, 2005
    Publication date: November 6, 2008
    Applicant: GENUSION, INC.
    Inventors: Natsuo Ajika, Shoji Shukuri, Masaaki Mihara, Moriyoshi Nakashima
  • Patent number: 7447082
    Abstract: A single-poly non-volatile memory cell that is fully compatible with nano-scale semiconductor manufacturing process is provided. The single-poly non-volatile memory cell includes an ion well, a gate formed on the ion well, a gate dielectric layer between the gate and the ion well, a dielectric stack layer on sidewalls of the gate, a source doping region and a drain doping region. The dielectric stack layer includes a first oxide layer deposited on the sidewalls of the gate and extends to the ion well, and a silicon nitride layer formed on the first oxide layer. The silicon nitride layer functions as a charge-trapping layer.
    Type: Grant
    Filed: November 1, 2006
    Date of Patent: November 4, 2008
    Assignee: eMemory Technology Inc.
    Inventors: Shih-Chen Wang, Hsin-Ming Chen, Chun-Hung Lu, Ming-Chou Ho, Shih-Jye Shen, Ching-Hsiang Hsu
  • Patent number: 7447073
    Abstract: A memory system includes memory cells arranged in sectors. A decoder corresponding to a sector disables memory cells having a defective top gate. The decoder may include a low voltage or high voltage latch for the disabling. A top gate handling algorithm is included. The memory system may include dynamic top gate coupling. A programming algorithm and waveforms with top gate handling is included.
    Type: Grant
    Filed: February 16, 2007
    Date of Patent: November 4, 2008
    Assignee: Silicon Storage Technology, Inc.
    Inventors: Hieu Van Tran, Hung Quoc Nguyen, Anh Ly, Sheng-Hsiung Hsueh, Sang Thanh Nguyen, Loc B. Hoang, Steve Choi, Thuan T. Vu
  • Publication number: 20080239817
    Abstract: A nonvolatile semiconductor memory device includes a semiconductor substrate having a source, a drain, and a channel region between the source and the drain. The channel region has a first end portion near the drain, a second end portion near the source, and a middle portion between the first and second end portions. The first and second end portions having approximately same width. The memory device is electrically erased by using a hot carrier generated in the first end portion due to avalanche breakdown. The channel region includes a first channel extending from the drain and a second channel adjacent to the first channel. An impurity concentration of the second channel is higher than that of the first channel. An interface between the first and second channels is located in the middle portion between the first and second end portions.
    Type: Application
    Filed: March 31, 2008
    Publication date: October 2, 2008
    Applicant: DENSO CORPORATION
    Inventors: Mitsutaka Katada, Yukiaki Yogo, Akira Tai, Yukihiko Watanabe
  • Patent number: 7423906
    Abstract: A memory cell having a programmable solid state electrolyte layer, a writing line and a controllable switch that is arranged between the solid state electrolyte layer and the writing line. The controllable switch has a control input that is connected with a selecting line and the switch also has a limiting element that limits a current through the solid state electrolyte layer to a predetermined amount of electric charge for a write operation.
    Type: Grant
    Filed: March 14, 2006
    Date of Patent: September 9, 2008
    Assignee: Infineon Technologies AG
    Inventor: Ralf Symanczyk
  • Patent number: 7420842
    Abstract: A storage transistor is programmed as a non-volatile memory element by biasing the source and drain while a programming voltage is applied to the gate. The substrate is held at a different potential than the source/drain to insure that the greatest difference in voltage during the programming step occurs between the channel region and the gate, rather than the gate and the source/drain. The programming voltage heats the channel region to form a non-volatile low-resistance connection between the source and drain, which is read to determine the programmed state.
    Type: Grant
    Filed: August 24, 2005
    Date of Patent: September 2, 2008
    Assignee: Xilinx, Inc.
    Inventors: Michael G. Ahrens, Shahin Toutounchi, James Karp, Jongheon Jeong
  • Patent number: 7414894
    Abstract: A number of methods for identifying cells with poor subthreshold slope and reduced transconductance. A first set of techniques focuses on the poor subthreshold behavior of degraded storage elements by cycling cells and then programming them to a state above the ground state and the reading them with a control gate voltage below the threshold voltage of this state to see if they still conduct. A second set of embodiments focuses on weak transconductance behavior by reading programmed cells with a control gate voltage well above the threshold voltage. A third set of embodiments alters the voltage levels at the source-drain regions of the storage elements. The current-voltage curve of a good storage element is relatively stable under this shift in bias conditions, while degraded elements exhibit a larger shift. The amount of shift can be used to differentiate the good elements from the bad.
    Type: Grant
    Filed: March 23, 2006
    Date of Patent: August 19, 2008
    Assignee: SanDisk Corporation
    Inventors: Jeffrey W. Lutze, Jian Chen, Yan Li, Kazunori Kanebako, Tomoharu Tanaka
  • Publication number: 20080181006
    Abstract: A method of programming a memory cell is described. First, a first programming operation is performed to inject electrons into a nitride layer adjacent to a side of a drain. The first programming operation includes applying a first gate voltage to a gate, applying a first drain voltage to the drain, applying a first source voltage to a source, and applying a first substrate, voltage to a substrate. Then, a second programming operation is performed to inject the electrons into the nitride layer adjacent to a side of the source. The second programming operation includes applying a second gate voltage to the gate, applying a second drain voltage to the drain, applying a second source voltage to the source, and applying a second substrate voltage to the substrate. The second gate voltage is less than the first gate voltage.
    Type: Application
    Filed: January 29, 2007
    Publication date: July 31, 2008
    Applicant: MACRONIX INTERNATIONAL CO., LTD.
    Inventor: Chao-I Wu
  • Patent number: 7405969
    Abstract: A non-volatile electrically erasable programmable read only memory (EEPROM) capable of storing two bit of information having a nonconducting charge trapping dielectric, such as silicon nitride, sandwiched between two silicon dioxide layers acting as electrical insulators is disclosed. The invention includes a method of programming, reading and erasing the two bit EEPROM device. The nonconducting dielectric layer functions as an electrical charge trapping medium. A conducting gate layer is placed over the upper silicon dioxide layer. A left and a right bit are stored in physically different areas of the charge trapping layer, near left and right regions of the memory cell, respectively. Each bit of the memory device is programmed in the conventional manner, using hot electron programming, by applying programming voltages to the gate and to either the left or the right region while the other region is grounded.
    Type: Grant
    Filed: August 1, 2006
    Date of Patent: July 29, 2008
    Assignee: Saifun Semiconductors Ltd.
    Inventor: Boaz Eitan
  • Publication number: 20080158965
    Abstract: A non-volatile memory including a substrate, a select gate, two floating gates, a control gate, and a doped region is described. The select gate is disposed on the substrate. The two floating gates are disposed on both sides of the select gate, and the top surface of the floating gates is higher than that of the select gate forming a hollow structure on the select gate between the two floating gates. The control gate disposed on the substrate covers the select gate and the two floating gates and fills the hollow structure. The doped region is disposed in the substrate on one side of the two floating gates opposite to the select gate.
    Type: Application
    Filed: January 15, 2008
    Publication date: July 3, 2008
    Applicant: POWERCHIP SEMICONDUCTOR CORP.
    Inventors: Pin-Yao Wang, Liang-Chuan Lai
  • Publication number: 20080151627
    Abstract: A low voltage method of 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: Application
    Filed: December 21, 2006
    Publication date: June 26, 2008
    Inventors: Dana Lee, Jeffrey Lutze
  • Publication number: 20080151629
    Abstract: The degree of integration and the number of rewriting of a semiconductor device having a nonvolatile memory element are improved. A first MONOS nonvolatile-memory-element and a second MONOS nonvolatile-memory-element having a large gate width compared with the first MONOS nonvolatile-memory-element are mounted together on the same substrate, and the first MONOS nonvolatile-memory-element is used for storing program data which is scarcely rewritten, and the second MONOS nonvolatile-memory-element is used for storing processed data which is frequently rewritten.
    Type: Application
    Filed: January 25, 2008
    Publication date: June 26, 2008
    Inventors: Fumitoshi ITO, Yoshiyuki Kawashima, Takeshi Sakai, Yasushi Ishii, Yasuhiro Kanamaru, Takashi Hashimoto, Makoto Mizuno, Kousuke Okuyama, Yukiko Manabe
  • Publication number: 20080151628
    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: Application
    Filed: December 21, 2006
    Publication date: June 26, 2008
    Inventors: Dana Lee, Jeffrey Lutze
  • Publication number: 20080080245
    Abstract: A P-channel memory is provided. Each memory unit is constructed of a substrate, a gate structure, a first charge trapping layer, a second charge trapping layer, a first source/drain, and a second source/drain. The gate structure is located above the substrate. The first charge trapping layer and the second charge trapping layer are located on both sidewalls of the gate structure for storing two bit of data in a single memory unit. The first source/drain and the second source/drain are located in the substrate on both sides of the gate structure.
    Type: Application
    Filed: December 15, 2005
    Publication date: April 3, 2008
    Inventor: Chih-Cheng Liu
  • Patent number: 7333382
    Abstract: An apparatus for controlling generation of pulses for refresh operations of a memory device having a pad to transfer information and to receive signals from an external interface. The apparatus includes a switch, coupled to a current source and to the pad receiving signals from the external interface. The switch outputs one of the signals from the current source or the pad in response to a switch control signal. An oscillator is coupled to the switch and generates the refresh operation pulses in response to the output from the switch.
    Type: Grant
    Filed: February 16, 2006
    Date of Patent: February 19, 2008
    Assignee: Infineon Technologies AG
    Inventors: Wolfgang Hokenmaier, Helmut Seitz
  • Patent number: 7307882
    Abstract: A non-volatile memory having a gate structure, a pair of storage units and two assist gates is provided. The gate structure is disposed on the substrate. The storage units are disposed on the sidewalls of the gate structure. The assist gates are disposed on the respective sides of the gate structure and adjacent to the storage units. Each assist gate is shared between two adjacent memory cells. The gate structure, the storage units and the assist gates are electrically isolated from one another.
    Type: Grant
    Filed: June 29, 2005
    Date of Patent: December 11, 2007
    Assignee: Macronix International Co., Ltd.
    Inventors: Cheng-Hsing Hsu, Hao-Ming Lien
  • Patent number: 7283391
    Abstract: A semiconductor memory device comprises: a plurality of memory elements; at least one bit line, wherein a memory operation is performed via at least a portion of the bit line with respect to at least one of the plurality of memory elements; and a load resistance regulating circuit for changing a resistance value to reduce or eliminate a difference in bit line load resistance depending on a position of the memory element.
    Type: Grant
    Filed: September 3, 2004
    Date of Patent: October 16, 2007
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Naoki Ueda, Nobuhiko Ito, Yoshimitsu Yamauchi
  • Patent number: 7248504
    Abstract: A data processing device which selects either emission of electrons from a nonvolatile memory cell or injection of electrons into it for each bit. A memory array includes a plurality of nonvolatile memory cells each having a pair of a first MOS transistor and a second MOS transistor where the first transistor has a charge retention layer and a memory gate and is used for data storage and the second transistor has a control gate and selectively connects the first transistor to a bit line. When negative voltage is applied to a memory gate, electrons held by a charge retention layer are emitted through hot carriers generated in a nonvolatile memory cell channel region for erasing; and when positive voltage is applied to the memory gate, electrons are injected into the charge retention layer through hot carriers generated in the nonvolatile memory cell channel region for writing and controls the generation and suppression of hot carriers by means of bit line voltage on each bit line.
    Type: Grant
    Filed: June 1, 2005
    Date of Patent: July 24, 2007
    Assignee: Renesas Technology Corp.
    Inventors: Akira Kato, Toshihiro Tanaka, Takashi Yamaki
  • Patent number: 7199424
    Abstract: An memory device, and method of making same, that includes source and drain regions defining a channel region therebetween. A select gate is formed over and insulated from a first portion of the channel region. A conductive floating gate is disposed over and insulated from the source region and a second portion of the channel region. A notch is formed in the floating gate bottom surface having an edge that is either aligned with an edge of the source region or is disposed over the source region. A conductive control gate is disposed adjacent to the floating gate. By having the source region terminate under the thicker insulation region provided by the notch, the breakdown voltage of the source junction is increased. Alternately, the lower portion of the floating gate is formed entirely over the source region, for producing fringing fields to control the adjacent portion of the channel region.
    Type: Grant
    Filed: January 23, 2006
    Date of Patent: April 3, 2007
    Assignee: Integrated Memory Technologies, Inc.
    Inventors: Ching-Shi Jenq, Ting P. Yen
  • Patent number: 7169671
    Abstract: A nonvolatile semiconductor memory includes a transistor, one or two resistance-change portions, and one or two charge accumulation portions. The transistor has a control electrode, first main electrode region, and second main electrode region. Each resistance-change portion is of a second conductivity type having impurity concentration lower than that of the first and second main electrode regions. The charge-accumulation portions are provided on the associated resistance-change portions. Each charge accumulation portion has an insulating layer, and is capable of accumulating charge.
    Type: Grant
    Filed: February 18, 2005
    Date of Patent: January 30, 2007
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Takashi Ono
  • Patent number: 7158420
    Abstract: A charge trapping memory device in which a field induced inversion layer is used to replace the source and drain implants. The memory cell are adapted to store two bits, one on the left side and one on the right side of the charge trapping structure. A positive threshold voltage erase state is induced using negative gate voltage Fowler Nordheim FN tunneling which establishes a charge balance condition at a positive voltage. A low current, source side, hot electron injection programming method is used.
    Type: Grant
    Filed: April 29, 2005
    Date of Patent: January 2, 2007
    Assignee: Macronix International Co., Ltd.
    Inventor: Hsiang Lan Lung
  • Patent number: 7151293
    Abstract: A SONOS memory cell, formed within a semiconductor substrate, includes a bottom dielectric disposed on the semiconductor substrate, a charge trapping material disposed on the bottom dielectric, and a top dielectric disposed on the charge trapping material. Furthermore, the SONOS memory cell includes a word-line gate structure disposed on the top dielectric and at least one bit-line gate for inducing at least one inversion bit-line within the semiconductor substrate.
    Type: Grant
    Filed: August 27, 2004
    Date of Patent: December 19, 2006
    Assignee: Spansion, LLC
    Inventors: Hidehiko Shiraiwa, Jaeyong Park, Satoshi Torii, Hideki Arakawa, Masaru Yano
  • Patent number: 7057931
    Abstract: A method for programming a storage element and a storage element programmed using gate induced junction leakage current are provided. The element may include at least a floating gate on a substrate, an active region in the substrate, and a second gate adjacent to the floating gate. The method may include the steps of: creating an inversion region in the substrate below the floating gate by biasing the first gate; and creating a critical electric field adjacent to the second gate. Creating a critical electric field may comprise applying a first positive bias to the active region; and applying a bias less than the first positive bias to the second gate. The element further includes a first bias greater than zero volts applied to the active region and a second bias greater than the first bias applied to the floating gate and a third bias less than or equal to zero applied to the second gate.
    Type: Grant
    Filed: November 7, 2003
    Date of Patent: June 6, 2006
    Assignee: Sandisk Corporation
    Inventors: Jeffrey W. Lutze, Chan-Sui Pang
  • Patent number: 7046555
    Abstract: A number of methods for identifying cells with poor subthreshold slope and reduced transconductance. A first set of techniques focuses on the poor subthreshold behavior of degraded storage elements by cycling cells and then programming them to a state above the ground state and the reading them with a control gate voltage below the threshold voltage of this state to see if they still conduct. A second set of embodiments focuses on weak transconductance behavior by reading programmed cells with a control gate voltage well above the threshold voltage. A third set of embodiments alters the voltage levels at the source-drain regions of the storage elements. The current-voltage curve of a good storage element is relatively stable under this shift in bias conditions, while degraded elements exhibit a larger shift. The amount of shift can be used to differentiate the good elements from the bad.
    Type: Grant
    Filed: September 17, 2003
    Date of Patent: May 16, 2006
    Assignees: SanDisk Corporation, Kabushiki Kaisha Toshiba
    Inventors: Jeffrey W. Lutze, Jian Chen, Yan Li, Kazunori Kanebako, Tomoharu Tanaka
  • Patent number: 7009244
    Abstract: An memory device, and method of making same, that includes source and drain regions defining a channel region therebetween. A select gate is formed over and insulated from a first portion of the channel region. A conductive floating gate is disposed over and insulated from the source region and a second portion of the channel region. A notch is formed in the floating gate bottom surface having an edge that is either aligned with an edge of the source region or is disposed over the source region. A conductive control gate is disposed adjacent to the floating gate. By having the source region terminate under the thicker insulation region provided by the notch, the breakdown voltage of the source junction is increased. Alternately, the lower portion of the floating gate is formed entirely over the source region, for producing fringing fields to control the adjacent portion of the channel region.
    Type: Grant
    Filed: June 28, 2004
    Date of Patent: March 7, 2006
    Assignee: Integrated Memory Technologies, Inc.
    Inventors: Ching-Shi Jenq, Ting P. Yen
  • Patent number: 7009884
    Abstract: A semiconductor storage device includes a memory cell array 21 in which a plurality of memory elements are arranged and a program verify circuit 30. The memory element 1, 33 includes a gate electrode 104 formed on a semiconductor layer 102 via a gate insulator 103, a channel region arranged below the gate electrode 104, diffusion regions 107a, 107b that are located on opposite sides of the channel region and have a conductive type opposite to that of the channel region, and memory function bodies 109 that are located on opposite sides of the gate electrode 104 and have a function of retaining electric charge. A program load register 32 of the program verify circuit 30 eliminates a state that a memory element 33 which has initially been verified as having been correctly programmed needs to be further programmed.
    Type: Grant
    Filed: May 19, 2004
    Date of Patent: March 7, 2006
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshifumi Yaoi, Hiroshi Iwata, Akihide Shibata, Yoshinao Morikawa, Masaru Nawaki
  • Patent number: 7003619
    Abstract: The preferred embodiments described herein provide a memory device and method for storing and reading a file system structure in a write-once memory array. In one preferred embodiment, a plurality of bits representing a file system structure is inverted and stored in a write-once memory array. When the inverted plurality of bits is read from the memory array, the bits are inverted to provide the file system structure bits in their original, non-inverted configuration. With this preferred embodiment, a file system structure can be updated to reflect data stored in the memory array after the file system structure was written. Other preferred embodiments are provided, and each of the preferred embodiments described herein can be used alone or in combination with one another.
    Type: Grant
    Filed: June 8, 2001
    Date of Patent: February 21, 2006
    Assignee: Matrix Semiconductor, Inc.
    Inventors: Christopher S. Moore, James E. Schneider, J. James Tringali, Roger W. March
  • Patent number: 6996660
    Abstract: The preferred embodiments described herein provide a memory device and method for storing and reading data in a write-once memory array. In one preferred embodiment, a plurality of bits representing data is inverted and stored in a write-once memory array. When the inverted plurality of bits is read from the memory array, the bits are inverted to provide the data in its original, non-inverted configuration. By storing data bits in an inverted form, the initial, un-programmed digital state of the memory array is redefined as the alternative, programmed digital state. Other preferred embodiments are provided, and each of the preferred embodiments described herein can be used alone or in combination with one another. For example, the embodiments in which data bits are inverted can be used alone or in combination with the embodiments in which data is redirected.
    Type: Grant
    Filed: June 8, 2001
    Date of Patent: February 7, 2006
    Assignee: Matrix Semiconductor, Inc.
    Inventors: Christopher S. Moore, James E. Schneider, J. James Tringali, Roger W. March
  • Patent number: 6925007
    Abstract: Non-volatile memory cells store a level of charge corresponding to the data being stored in a dielectric material storage element that is sandwiched between a control gate and the semiconductor substrate surface over channel regions of the memory cells. More than two memory states are provided by one of more than two levels of charge being stored in a common region of the dielectric material. More than one such common region may be included in each cell. In one form, two such regions are provided adjacent source and drain diffusions in a cell that also includes a select transistor positioned between them. In another form, NAND arrays of strings of memory cells store charge in regions of a dielectric layer sandwiched between word lines and the semiconductor substrate.
    Type: Grant
    Filed: October 25, 2002
    Date of Patent: August 2, 2005
    Assignee: SanDisk Corporation
    Inventors: Eliyahou Harari, George Samachisa, Jack H. Yuan, Daniel C. Guterman
  • Patent number: 6917069
    Abstract: A self aligned method of forming a semiconductor memory array of floating gate memory cells in a semiconductor substrate, and an array formed thereby, whereby each memory cell includes a trench formed into a surface of a semiconductor substrate, spaced apart source and drain regions with a channel region formed therebetween. The drain region is formed underneath the trench, and the channel region includes a first portion that extends substantially vertically along a sidewall of the trench and a second portion that extends substantially horizontally along the surface of the substrate. An electrically conductive floating gate is formed over and insulated from at least a portion of the channel region and a portion of the source region. An electrically conductive control gate is formed having a first portion disposed in the trench and a second portion formed over but insulated from the floating gate.
    Type: Grant
    Filed: October 17, 2001
    Date of Patent: July 12, 2005
    Assignee: Silicon Storage Technology, Inc.
    Inventors: Sohrab Kianian, Chih Hsin Wang