Program Gate Patents (Class 365/185.14)
-
Patent number: 6894928Abstract: An apparatus and method is provided for adjusting a reference voltage at an output terminal of a floating gate reference voltage generator circuit in order to improve the accuracy of the reference voltage at an input terminal of a load circuit. The apparatus and method compensates for the voltage drop produced between the output terminal of the reference voltage generator circuit and the input terminal of the load circuit, and includes a capacitor for capacitively coupling the voltage at the input terminal of said load circuit to a floating gate, and a differential amplifier operatively coupled to the floating gate which acts in response to the capacitively coupled load circuit input voltage to adjust the voltage at the output terminal such that the voltage at the input terminal of the load circuit becomes equal to the reference voltage.Type: GrantFiled: January 28, 2003Date of Patent: May 17, 2005Assignee: Intersil Americas Inc.Inventor: William H. Owen
-
Method of programming semiconductor memory device having memory cells and method of erasing the same
Patent number: 6894929Abstract: The present invention provides a method of programming, into a computer, a memory array having a plurality of memory cells, including a verification step 1 of verifying whether a memory cell has been already programmed or it has not been programmed yet per memory cell to be programmed, a flagging step 2 of flagging the memory cell in the case where it is verified that the memory cell has not been programmed yet in the several verifying steps, to which the memory cell is subjected thereafter, even if it is verified that the memory cell has been already programmed, a first application step 3 of applying a programming pulse having a programming level to the not-programmed memory cell without any flag, a repeat step 4 of repeating the verification step 1, the flagging step 2 and the first application step 3 until it is verified that all of the memory cells have been already programmed at least once, and a second application step 5 of applying a boost pulse having a boost programming level lower than that of the pType: GrantFiled: May 10, 2004Date of Patent: May 17, 2005Assignee: Sharp Kabushiki KaishaInventors: Nobuaki Matsuoka, Masaru Nawaki, Yoshinao Morikawa, Hiroshi Iwata, Akihide Shibata -
Patent number: 6888755Abstract: A flash NAND type EEPROM system with individual ones of an array of charge storage elements, such as floating gates, being capacitively coupled with at least two control gate lines. The control gate lines are preferably positioned between floating gates to be coupled with sidewalls of floating gates. The memory cell coupling ratio is desirably increased, as a result. Both control gate lines on opposite sides of a selected row of floating gates are usually raised to the same voltage while the second control gate lines coupled to unselected rows of floating gates immediately adjacent and on opposite sides of the selected row are kept low. The control gate lines can also be capacitively coupled with the substrate in order to selectively raise its voltage in the region of selected floating gates. The length of the floating gates and the thicknesses of the control gate lines can be made less than the minimum resolution element of the process by forming an etch mask of spacers.Type: GrantFiled: October 28, 2002Date of Patent: May 3, 2005Assignee: SanDisk CorporationInventor: Eliyahou Harari
-
Patent number: 6885587Abstract: A novel structure of nonvolatile memory is disclosed. The non-volatile memory includes two serially connected PMOS transistors. The characteristic of the devices is that bias is not necessary to apply to the floating gate during the programming mode. Thus, the control gate is omitted for the structure or layout, thereby saving the space for making the control gate. The carrier may be “automatically injected” into floating gate for programming the status of the devices.Type: GrantFiled: August 18, 2003Date of Patent: April 26, 2005Assignee: eMemory Technology Inc.Inventors: Ching-Sung Yang, Shih-Jye Shen, Ching-Hsiang Hsu
-
Patent number: 6882571Abstract: A memory cell comprises a multilayer gate heating structure formed over a channel region between source and drain regions. The multilayer gate heating structure comprises polysilicon and metal silicide layers stacked over a similarly shaped gate oxide. When a programming voltage is applied across the metal silicide layer, there is intense localized heating. The heating causes segregation of the channel dopant atoms towards the source and drain regions, lowering the threshold voltage of the device. The heating causes carrier activation in the polysilicon layer and dopant penetration through the oxide layer into the channel region, thereby increasing the threshold voltage of the device.Type: GrantFiled: October 24, 2003Date of Patent: April 19, 2005Assignee: Xilinx, Inc.Inventor: Kevin T. Look
-
Patent number: 6859393Abstract: A ground structure for page read and page write for flash memory. An array structure of flash memory cells comprises a plurality of sectors. Each sector comprises I/O blocks plus reference arrays and an array of redundant cells. Each I/O block comprises sub I/O blocks. Each sub I/O block within an I/O block, as well as other structures including reference cells, redundant cells and edge structures is coupled to a unique ground reference signal. These unique ground reference signals may be selectively coupled to a system ground or a biased ground reference. This novel ground arrangement enables a page read operation in which one bit from each sub I/O block can be read simultaneously. In addition, one bit from each I/O block may be programmed simultaneously. Further, the ground reference voltage for cells of the array may be selectively adjusted to optimize operation.Type: GrantFiled: October 4, 2002Date of Patent: February 22, 2005Assignee: FASL, LLCInventors: Tien-Chun Yang, Shigekazu Yamada, Ming-Huei Shieh, Pau-Ling Chen
-
Patent number: 6859408Abstract: Method and apparatus for regulating an antifuse programming current by lightly doping an electrically connected region so that the resistance of the region responds in a non-linear manner to changes in voltage. In this way a variable resistor or a variably resistive transistor may be created which vary their resistance in response to an applied voltage and which may thereby limit a programming current while not limiting a lesser, reading current to a serially connected antifuse.Type: GrantFiled: August 29, 2002Date of Patent: February 22, 2005Assignee: Micron Technology, Inc.Inventors: Stephen R. Porter, Scott J. Derner
-
Patent number: 6856540Abstract: A programmable memory cell comprised of a transistor located at the crosspoint of a column bitline and a row wordline is disclosed. The transistor has its gate formed from the column bitline and its source connected to the row wordline. The memory cell is programmed by applying a voltage potential between the column bitline and the row wordline to produce a programmed n+region in the substrate underlying the gate of the transistor.Type: GrantFiled: May 30, 2003Date of Patent: February 15, 2005Assignee: Kilopass Technologies, Inc.Inventors: Jack Zezhong Peng, David Fong
-
Patent number: 6853583Abstract: Methods and apparatuses prevent overtunneling in pFET-based nonvolatile floating gate memory (NVM) cells. During a tunneling process, in which charge carriers are removed from a floating gate of a pFET-based NVM cell, a channel current of a memory cell transistor is monitored and compared to a predetermined minimum channel current required to maintain a conducting channel in an injection transistor of the memory cell. When the monitored channel current drops below the predetermined minimum channel current, charge carriers are injected onto the floating gate by impact-ionized hot-electron injection (IHEI) so that overtunneling is avoided.Type: GrantFiled: September 16, 2002Date of Patent: February 8, 2005Assignee: Impinj, Inc.Inventors: Christopher J. Diorio, Chad Lindhorst, Shail Srinivas, Alberto Pesavento, Troy Gilliland
-
Patent number: 6844584Abstract: Each memory cell is a memory transistor which is provided on a top side of a semiconductor body and has a gate electrode which is arranged in a trench located between a source region and a drain region that are formed in the semiconductor material. The gate electrode is separated from the semiconductor material by a dielectric material. At least between the source region and the gate electrode and between the drain region and the gate electrode, there is an oxide-nitride-oxide layer sequence. The layer sequence is provided for the purpose of trapping charge carriers at the source and the drain.Type: GrantFiled: August 9, 2001Date of Patent: January 18, 2005Assignee: Infineon Technologies AGInventors: Herbert Palm, Josef Willer, Achim Gratz, Jakob Kriz, Mayk Roehrich
-
Patent number: 6842372Abstract: An EEPROM memory device includes a substrate of a first conductivity type having a cell well region of a second conductivity type therein. A floating-gate transistor of the first conductivity type resides in the cell well region and includes a first region separated from a second region by a channel region. A write transistor of the second conductivity type resides in the substrate and includes a first region separated from a second region by a channel region. The second region partially extends into the cell well region and forms a p-n junction with the second region of the floating-gate transistor. The process for fabricating the EEPROM device includes forming the cell well region in the substrate by creating a retrograde doping profile. In operation, the EEPROM device transfers electrons between the cell well region and the floating-gate electrode during both programming and erasing operations.Type: GrantFiled: September 6, 2002Date of Patent: January 11, 2005Assignee: Lattice Semiconductor CorporationInventor: YongZhong Hu
-
Patent number: 6836433Abstract: A rewrite disable control method for a non-volatile semiconductor storage device is disclosed for relying on a majority decision to determine whether a rewrite is disabled or enabled. A write disable control signal generating circuit reads three write disable flags of the same contents stored in security flag storage areas of three memory blocks, respectively, and makes a majority decision to determine a disable/enable state to establish the logic of a write disable control signal. Even if a power supply is instantaneously interrupted during an erasure of a certain block to cause a change in the security flag associated with one memory block, the security flags stored in the two remaining memory blocks maintain the original values, thereby making it possible to effectively prevent a trouble in which an unintended disable setting is validated.Type: GrantFiled: July 2, 2003Date of Patent: December 28, 2004Assignee: NEC Electronics CorporationInventor: Takao Kondo
-
Patent number: 6835979Abstract: A nonvolatile memory cell which is highly scalable includes a cell formed in a triple well. A select transistor can have a source which also acts as the emitter of a lateral bipolar transistor. The lateral bipolar transistor operates as a charge injector. The charge injector provides electrons for substrate hot electron injection of electrons onto the floating gate for programming. The cell depletion/inversion region may be extended by forming a capacitor as an extension of the control gate over the substrate between the source and channel of said sense transistor.Type: GrantFiled: June 12, 2000Date of Patent: December 28, 2004Assignee: Altera CorporationInventors: David K. Liu, Ting-wah Wong
-
Patent number: 6831863Abstract: The present invention relates to an array of flash memory cells whose unit cell includes a single transistor of MONOS/SONOS structure (Metal/poly-Silicon Oxide Nitride Oxide Semiconductor) and to data programming and erasing using the same. The array of the flash memory cells includes a plurality of flash memory cells arranged in a form of a matrix. The matrix includes a plurality of word lines arranged in one line direction and connected to gates of the flash memory cells is a row, a plurality of selection lines arranged in a direction perpendicular to the word lines and connected to the sources of the flash memory cells arranged in a column, and a plurality of bit lines arranged in a direction parallel to the selection lines and connected to the drains of the flash memory cells of the same column. To program and erase the cells, different biasing conditions are applied to the word lines, selection lines, bit lines, and the wells of the transistors.Type: GrantFiled: April 14, 2003Date of Patent: December 14, 2004Assignee: Hyundai Electronics Industries Co., Ltd.Inventors: Sang Bae Yi, Jae Seung Choi
-
Patent number: 6816414Abstract: A method of discharging a charge storage location of a transistor of a non-volatile memory includes applying first and second voltages to a control gate and a well region, respectively, of the transistor. The first voltage is applied to the control gate of the transistor, wherein the control gate has at least a portion located adjacent to a select gate of the transistor. The transistor includes a charge storage location having nanoclusters disposed within dielectric material of a structure of the transistor located below the control gate. Lastly, a second voltage is applied to the well region located below the control gate. Applying the first voltage and the second voltage generates a voltage differential across the structure for discharging electrons from the nanoclusters of the charge storage location.Type: GrantFiled: July 31, 2003Date of Patent: November 9, 2004Assignee: Freescale Semiconductor, Inc.Inventor: Erwin J. Prinz
-
Publication number: 20040213046Abstract: An electrically erasable programmable read-only memory receives a single supply voltage and a ground voltage, and generates a first voltage higher than both the supply voltage and the ground voltage, and a second voltage lower than both the supply voltage and the ground voltage. Each memory cell in the memory has a nonvolatile storage transistor with a floating gate. To erase the memory cell, the first voltage is applied on a first side of the floating gate and the second voltage is on a second, opposite side of the floating gate. To program the memory cell, the second voltage is applied on the first side of the floating gate, and the first voltage is applied on the second side of the floating gate.Type: ApplicationFiled: May 20, 2004Publication date: October 28, 2004Applicant: Oki Electric Industry Co., Ltd.Inventor: Takuji Yoshida
-
Patent number: 6804149Abstract: The present invention relates to a nonvolatile memory cell and/or array and a method of operating the same high integrated density nonvolatile memory cell enabling high integration density, low voltage programming and/or high speed programming, a method of programming same and a nonvolatile memory array. A p-well 101 is formed in a surface of a substrate 10 and a channel forming semiconductor region 110 is defined in a surface of the p-well 101 and separated by a first n+ region 121 and a second n+ region 122. A carrier-supplying portion (CS: carrier supply) 111 is formed coming into contact with the first n+ region 121 and a carrier-acceleration-injection portion 112 (AI: acceleration and injection) is in contact with the second n+ region 122 in the channel forming semiconductor region 110 wherein the carrier-supplying portion 111 and carrier-acceleration-injection portion 112 are in contact with each other.Type: GrantFiled: March 20, 2002Date of Patent: October 12, 2004Assignee: New Halo, Inc.Inventors: Seiki O. Ogura, Yutaka Hayashi
-
Patent number: 6801458Abstract: A memory cell array has a unit formed from one memory cell and two select transistors sandwiching the memory cell. One block has one control gate line. Memory cells connected to one control gate line form one page. A sense amplifier having a latch function is connected to a bit line. In a data change operation, data of memory cells of one page are read to the sense amplifiers. After data are superscribed on data in the sense amplifiers, and a page erase is performed, data in the sense amplifiers are programmed in the memory cells of one page. Superscription of data in the sense amplifiers allows a data change operation for byte data or page data.Type: GrantFiled: August 12, 2003Date of Patent: October 5, 2004Assignee: Kabushiki Kaisha ToshibaInventors: Koji Sakui, Junichi Miyamoto
-
Patent number: 6798694Abstract: For a multi-sectored flash memory array with bitlines spanning multiple erase blocks, a bias scheme for programming an address in any erase sector while minimizing drain voltage induced disturb to cells in unselected erase sectors sharing the same bitlines.Type: GrantFiled: August 29, 2002Date of Patent: September 28, 2004Assignee: Micron Technology, Inc.Inventors: Andrei Mihnea, Vinod Lakhani
-
Patent number: 6791881Abstract: A semiconductor integrated circuit includes non-volatile memory elements (PM1, PM2), each of which has a first source electrode, a first drain electrode, a floating gate electrode and a control gate electrode and is capable of having different threshold voltages, and read transistor elements (DM1, DM2), each of which has a second source electrode and a second drain electrode and is capable of having different mutual conductances according to the threshold voltage of the non-volatile memory element. The read transistor element has a switching state according to the electron injection state or the electron emission state, in other words, the writing state or the erasing state of the floating gate electrode. In a read operation, it is not necessary to cause a channel current to flow according to the threshold voltage of the non-volatile memory element.Type: GrantFiled: July 28, 2003Date of Patent: September 14, 2004Assignee: Hitachi, Ltd.Inventors: Shoji Shukuri, Kazumasa Yanagisawa
-
Patent number: 6788573Abstract: The present invention discloses a non-volatile semiconductor memory device and a method of operating the same. More specifically, the present invention includes a semiconductor substrate having active and field regions, at least two non-volatile storage transistors each of which having a storage on the active region and a control gate at the storage, wherein at least two control gates are incorporated into a single control plate, and at least two selection transistors each of which corresponds to the non-volatile storage transistor, wherein each of the selection transistors connected to the corresponding non-volatile storage transistors for selecting the corresponding non-volatile storage transistors.Type: GrantFiled: November 21, 2001Date of Patent: September 7, 2004Inventor: Woong Lim Choi
-
Patent number: 6781187Abstract: A nonvolatile semiconductor memory device including a plurality of memory cells each of which has two MONOS memory cells controlled by one word gate and two control gates, the memory cells being arranged in first and second directions. Each two control gate lines connected in common with one sub control gate line have a wide spacing region having a large line-to-line width, a common connection region in which the two lines are connected in common in one line, and a narrow spacing region having a small line-to-line width which is disposed in a region other than the wide spacing region and the common connection region. The wide spacing regions are disposed in the second direction, one on both sides of the common connection region in first and second wiring-only regions in a memory cell array region. The wide spacing region is an enlarged region of bit lines in which a contact is formed. The common connection region is a discontinuous region of the bit line.Type: GrantFiled: May 24, 2002Date of Patent: August 24, 2004Assignee: Seiko Epson CorporationInventor: Yoshihito Owa
-
Patent number: 6768675Abstract: The present invention provides a stack-gate flash memory array. In the present invention, one bit line for a conventional memory cell had been divided two independent bit lines; two word lines have been combined together via the gate terminal of an isolated transistor. Because the bit lines are divided and the word lines will stop the leakage current via the isolated transistor, the leakage current would not affect the other memory cells. Hence, the present invention can avoid the data inaccuracy due to the leakage current resulting from the erratic bits, and thus can extend the flash memory's lifetime.Type: GrantFiled: August 11, 2003Date of Patent: July 27, 2004Assignee: Winbond Electronics Corp.Inventor: Chung-Meng Huang
-
Patent number: 6767790Abstract: A nonvolatile semiconductor storage device can achieve a shortened write time and a reduced absolute value of an operating voltage at the time of erasing. A P-type silicon substrate (1) is set at a ground level, a control gate (109) is set at a high voltage (Vp1), and a voltage of 0 V is applied to an access gate line connected in common to all access gates (7a) to set all the access gates (7a(n−4) to 7a(n+3)) at 0 V. When the threshold voltage of a memory transistor (MT(n)) is set into a written state, an N+ diffusion region (5(n)) is set at 0V. This causes tunnel injection of electrons into a floating gate (3a(n)) of the memory transistor (MT(n)) and thereby allows the memory transistor MT(n) to be set to a high threshold voltage (Vthp) without being influenced by the contents of writing to adjacent memory transistors.Type: GrantFiled: July 17, 2002Date of Patent: July 27, 2004Assignee: Renesas Technology Corp.Inventor: Kiyoteru Kobayashi
-
Patent number: 6754104Abstract: A semiconductor device including integrated insulated-gate field-effect transistor (IGFET) elements and one or more negative differential resistance (NDR) field-effect transistor elements, combined and formed on a common substrate. Thus, a variety of circuits, including logic and memory are implemented with a combination of conventional and NDR capable FETs. Because both types of elements share a number of common features, they can be fabricated with common processing operations to achieve better integration in a manufacturing facility.Type: GrantFiled: December 21, 2001Date of Patent: June 22, 2004Assignee: Progressant Technologies, Inc.Inventor: Tsu-Jae King
-
Patent number: 6738291Abstract: A nonvolatile semiconductor memory device prevents the voltage from dropping in a voltage raising circuit at the switching time of a control gate voltage at an address changing time. This nonvolatile semiconductor memory device has a voltage generation section which generates voltages for driving the control gates in a plurality of nonvolatile memory cells. The voltage generation section has the voltage raising circuit and a voltage control circuit. The voltage control circuit has a plurality of voltage input terminals and a plurality of voltage output terminals, and switches and outputs a plurality of voltages inputted from the voltage raising circuit through the voltage input terminals to the voltage output terminals in accordance with a selection state of then on volatile memory cells.Type: GrantFiled: February 3, 2003Date of Patent: May 18, 2004Assignee: Seiko Epson CorporationInventors: Teruhiko Kamei, Masahiro Kanai
-
Patent number: 6728139Abstract: Memory cells are divided into a plurality of series circuit units arranged in matrix fashion and comprising some memory cells connected in series. The memory cells each consist of non-volatile transistors provided with a control gate electrode, a floating gate electrode and an erase gate electrode. Bit lines to which one end of each of the series circuit units of the plurality of series circuit units arranged in one row are connected in common. Column lines are provided in common for the series circuit units that are arranged in one column and that are respectively connected to each control gate electrode of the memory cells constituting each of the series circuit unit. A voltage by which the selected non-volatile transistor works in a saturation state is applied to the control gate electrode of the selected transistor of a series circuit unit by a column line, thereby injecting hot electrons from the semiconductor substrate into the floating gate electrode.Type: GrantFiled: April 9, 2002Date of Patent: April 27, 2004Assignee: Kabushiki Kaisha ToshibaInventor: Fujio Masuoka
-
Patent number: 6710399Abstract: A nonvolatile semiconductor storage device includes a memory cell array region in which a plurality of memory cells are arranged, each of the memory cells having first and second nonvolatile memory elements and being controlled by one word gate and first and second control gates. In reading out data from one of the first and second nonvolatile memory elements of the memory cell, a control voltage of a control-gate-line selection switching element connected to a sub control gate line to which an override voltage is applied, is greater than that of a control-gate-line selection switching element connected to a sub control gate line to which a read voltage is applied.Type: GrantFiled: July 18, 2002Date of Patent: March 23, 2004Assignee: Seiko Epson CorporationInventor: Teruhiko Kamei
-
Patent number: 6680507Abstract: The present invention relates generally to semiconductor memory devices and more particularly to multi-bit flash electrically erasable programmable read only memory (EEPROM) devices that employ charge trapping within a floating gate to indicate a 0 or 1 bit state. A memory device is provided, according to an aspect of the invention, comprising a floating gate transistor having dual polysilicon floating gates with an isolation opening between floating gates. Processes for making the memory device according to the invention are also disclosed.Type: GrantFiled: April 11, 2001Date of Patent: January 20, 2004Assignee: Advanced Micro DevicesInventors: Tuan Pham, Angela T. Hui
-
Patent number: 6680865Abstract: In a non-volatile memory, the source potential of a selected cell transistor to be programmed is controlled to be changed in accordance with a distance between a program voltage generator connected to a bit line and to the selected cell transistor. When the distance between the selected cell transistor and the program voltage generator is a first distance, the source potential at the selected cell transistor is controlled to be a first potential, and when the distance between them is a second distance longer than the first distance, the source potential at the selected cell transistor is controlled to be a second potential higher than the first potential. As a result, the drain-source voltage at the selected cell transistor to be programmed can be optimized, and optimization of the programming can be implemented.Type: GrantFiled: March 18, 2002Date of Patent: January 20, 2004Assignee: Fujitsu LimitedInventor: Keisuke Watanabe
-
Patent number: 6678190Abstract: An erasable programmable read only memory comprising two serially connected P-type metal-oxide semiconductor (MOS) transistors wherein the control gate is omitted in the structure for layout as the bias is not necessary to apply to the floating gate during the programming mode.Type: GrantFiled: January 25, 2002Date of Patent: January 13, 2004Assignee: eMemory Technology Inc.Inventors: Ching-Sung Yang, Shih-Jye Shen, Ching-Hsiang Hsu
-
Patent number: 6674667Abstract: P-channel MOSFET devices are used as reprogrammable fuse or antifuse elements in a memory decode circuit by utilizing anomalous hole generation. An applied negative gate bias voltage is sufficiently large to cause tunnel electrons to gain enough energy to exceed the band gap energy of the oxide. This causes energetic hole-electron pairs to be generated in the silicon substrate. The holes are then injected from the substrate into the oxide, where they remain trapped. A large shift in the threshold voltage of the p-channel MOSFET results. The device can subsequently be reset by applying a positive gate bias voltage. Various circuits incorporating such fuse or antifuse elements are also disclosed.Type: GrantFiled: February 13, 2001Date of Patent: January 6, 2004Assignee: Micron Technology, Inc.Inventor: Leonard Forbes
-
Patent number: 6671205Abstract: A memory cell comprises a multilayer gate heating structure formed over a channel region between source and drain regions. The multilayer gate heating structure comprises polysilicon and metal silicide layers stacked over a similarly shaped gate oxide. When a programming voltage is applied across the metal silicide layer, there is intense localized heating. The heating causes segregation of the channel dopant atoms towards the source and drain regions, lowering the threshold voltage of the device. The heating causes carrier activation in the polysilicon layer and dopant penetration through the oxide layer into the channel region, thereby increasing the threshold voltage of the device.Type: GrantFiled: October 29, 2002Date of Patent: December 30, 2003Assignee: Xilinx, Inc.Inventor: Kevin T. Look
-
Patent number: 6657892Abstract: A memory cell array has a unit formed from one memory cell and two select transistors sandwiching the memory cell. One block has one control gate line. Memory cells connected to one control gate line form one page. A sense amplifier having a latch function is connected to a bit line. In a data change operation, data of memory cells of one page are read to the sense amplifiers. After data are superscribed on data in the sense amplifiers, and a page erase is performed, data in the sense amplifiers are programmed in the memory cells of one page. Superscription of data in the sense amplifiers allows a data change operation for byte data or page data.Type: GrantFiled: July 26, 2002Date of Patent: December 2, 2003Assignee: Kabushiki Kaisha ToshibaInventors: Koji Sakui, Junichi Miyamoto
-
Patent number: 6654291Abstract: Embodiments of the present invention are directed to an improved EEPROM (electrically erasable programmable read-only memory) in which the memory cells can be selectively erased. The EEPROM comprises a first memory cell having a first control gate and a first source, and a second memory cell having second control gate and a second source. If the first and second control gates are configured to receive a control gate voltage, the first source is configured to receive a first source voltage, and the second source is configured to receive a second source voltage different from the first source voltage so as to erase one of the first and second memory cells and to preserve another of the first and second memory cells.Type: GrantFiled: May 24, 2002Date of Patent: November 25, 2003Assignee: Mosel Vitelic, Inc.Inventors: Shang Tarng Jan, Der-Tsyr Fan
-
Patent number: 6650591Abstract: A nonvolatile semiconductor memory device has a plurality of memory cells arranged in first and second directions, each of the memory cells having two MONOS memory cells controlled by one word gate and two control gates. A memory cell array region has a plurality of control gate lines formed by connecting, in the first direction, control gates of the memory cells in each column arranged in the first direction, and sub control gate lines extending in the first direction in an upper layer of the plurality of control gate lines, the number of the sub control gate lines being half the number of the control gate lines. Each two control gate lines adjacent across the boundaries between the plurality of memory cells in the second direction are connected in common with one sub control gate line.Type: GrantFiled: May 24, 2002Date of Patent: November 18, 2003Assignee: Seiko Epson CorporationInventor: Yoshihito Owa
-
Patent number: 6646916Abstract: A non-volatile semiconductor memory device has a memory cell array region in which a plurality of memory cells are disposed in both a column direction and a row direction, each of the memory cells having first and second MONOS memory cells that are controlled by a word gate and first and second control gates. The memory cell array region is divided in the row direction into a plurality of sector regions 0 extending longitudinally in the column direction. Each of the sector regions has a plurality of memory cells disposed in each of columns arrayed in the column direction. A control gate drive section has a plurality of control gate drivers for each of the sector regions. Each of the control gate drivers sets a potential for the first and second control gates within the corresponding sector region, independently of the other sector regions.Type: GrantFiled: April 5, 2002Date of Patent: November 11, 2003Assignee: Seiko Epson CorporationInventor: Teruhiko Kamei
-
Patent number: 6643182Abstract: A dynamic RAM includes sense amplifiers each formed of a latch circuit consisting of MOSFETs of a first and second conductivity types with the application of a first and second voltages to the sources thereof, respectively, and having a pair of input/output nodes corresponding to a first bit line pair which is connected with a number of dynamic memory cells, and further includes pairs of switching MOSFETs of the first conductivity type which connect selectively an input/output node pair of the latch circuits to a pair of second bit lines provided commonly to a plurality of the first bit line pair in response to the reception of the select signal. The switching MOSFETs have their threshold voltage set smaller in terms of absolute value than the threshold voltage of the MOSFETs of the first conductivity type of the latch circuits, and the select signal has its level of turning off the switching MOSFETs set greater in terms of absolute value than the first voltage with respect to the second voltage.Type: GrantFiled: September 18, 2002Date of Patent: November 4, 2003Assignees: Hitachi, Ltd., Hitachi ULSI Systems Co., Ltd.Inventors: Kazumasa Yanagisawa, Toshio Sasaki, Satoru Nakanishi, Yoshihiko Yasu
-
Patent number: 6639835Abstract: Structures and methods involving non volatile depletion mode p-channel memory cells with an ultrathin tunnel oxide thicknesses, e.g. less than 50 Å, have been provided. Both the write and erase operations are performed by tunneling and method embodiments are included with the present invention. The floating gate of the depletion mode p-channel memory cell is adapted to hold a fixed charge over a limited range of floating gate potentials or electron energies. For the present invention, there is a range potentials applied to the floating gate for which there are no final nor initial states in the silicon substrate or p+ source region. In this range of potentials there can be no charge leakage, neither a gain nor a charge loss from the floating gate by tunneling or thermally assisted tunneling. In other words the potential of the floating gate can have different states and there will be no change in the charge state, due to leakage currents.Type: GrantFiled: February 29, 2000Date of Patent: October 28, 2003Assignee: Micron Technology, Inc.Inventor: Leonard Forbes
-
Patent number: 6636439Abstract: In the present invention a new method for program and program verify is described. The threshold voltage of the memory cell is shifted up and then measured with minimal charging and discharging of the bit lines and control gate lines. Bit line to control gate line capacitance is also used to reduce the number of voltage references needed. Program current is reduced by use of a load device coupled to the source diffusion. The result is increased program bandwidth with lower high voltage charge pump current consumption.Type: GrantFiled: February 20, 2003Date of Patent: October 21, 2003Assignee: Halo, LSI, INc.Inventors: Seiki Ogura, Tomoko Ogura, Nori Ogura
-
Patent number: 6628549Abstract: A semiconductor integrated circuit includes non-volatile memory elements (PM1, PM2), each of which has a first source electrode, a first drain electrode, a floating gate electrode and a control gate electrode and is capable of having different threshold voltages, and read transistor elements (DM1, DM2), each of which has a second source electrode and a second drain electrode and is capable of having different mutual conductances according to the threshold voltage of the non-volatile memory element. The read transistor element has a switching state according to the electron injection state or the electron emission state, in other words, the writing state or the erasing state of the floating gate electrode. In a read operation, it is not necessary to cause a channel current to flow according to the threshold voltage of the non-volatile memory element.Type: GrantFiled: August 29, 2002Date of Patent: September 30, 2003Assignee: Hitachi, Ltd.Inventors: Shoji Shukuri, Kazumasa Yanagisawa
-
Patent number: 6628546Abstract: In the present invention a new method for program and program verify is described. The threshold voltage of the memory cell is shifted up and then measured with minimal charging and discharging of the bit lines and control gate lines. Bit line to control gate line capacitance is also used to reduce the number of voltage references needed. Program current is reduced by use of a load device coupled to the source diffusion. The result is increased program bandwidth with lower high voltage charge pump current consumption.Type: GrantFiled: February 20, 2003Date of Patent: September 30, 2003Assignee: Halo LSI, Inc.Inventors: Seiki Ogura, Tomoko Ogura, Nori Ogura
-
Patent number: 6629309Abstract: A structure for programming a memory cell on an integrated circuit provides access at multiple mask levels of the integrated circuit to each of the programming voltages which may be used to program the memory cell. In an embodiment, the structure includes a conductive signal path extending through multiple horizontally conductive layers of the integrated circuit from a programming voltage pad (or node) to an input of the memory cell. The conductive signal path includes portions selected from multiple alternate path portions formed within the multiple horizontally conductive layers through which the signal path extends. An embodiment of a method for making a mask includes selecting one of multiple configurations of the programming structure portion to be formed using the mask. A computer-usable carrier medium may include digital representations of the alternative configurations for a programming structure portion from which a programming structure pattern may be selected.Type: GrantFiled: June 27, 2001Date of Patent: September 30, 2003Assignee: LSI Logic CorporationInventor: Ernest Allen, III
-
Patent number: 6618290Abstract: A method of programming that includes programming a fresh memory cell with a substrate that includes a first region and a second region with a channel therebetween and a gate above the channel, and a charge trapping region that contains a first amount of charge. Baking the programmed fresh cell causing a charge loss in the channel while the remaining charge within the channel is distributed more locally at the first region when compared to the distribution of charge prior to the baking.Type: GrantFiled: June 13, 2001Date of Patent: September 9, 2003Assignee: Advanced Micro Devices, Inc.Inventors: Janet S. Y. Wang, Narbeh Derhacobian
-
Patent number: 6611461Abstract: In the present invention a new method for program and program verify is described. The threshold voltage of the memory cell is shifted up and then measured with minimal charging and discharging of the bit lines and control gate lines. Bit line to control gate line capacitance is also used to reduce the number of voltage references needed. Program current is reduced by use of a load device coupled to the source diffusion. The result is increased program bandwidth with lower high voltage charge pump current consumption.Type: GrantFiled: February 20, 2003Date of Patent: August 26, 2003Assignee: Halo LSI, Inc.Inventors: Seiki Ogura, Tomoko Ogura, Nori Ogura
-
Patent number: 6611456Abstract: A memory system that reduces the number of memory cells programmed in a memory array is provided. A logic comparator determines whether more than half of the bits of a write data word require a program operation. If so, the logic comparator provides a status signal having a first state. A status signal having the first state causes the inverse of the write data word to be written to the memory array, along with the status signal. If the status signal does not have the first state, the write data word is written to the memory array, along with the status signal. During a read operation, a data word and corresponding status signal are read from the array. If the status signal has the first state, the inverse of the data word is provided as a read data word. Otherwise, the data word is provided as the read data word.Type: GrantFiled: July 3, 2001Date of Patent: August 26, 2003Assignee: Tower Semiconductor, Ltd.Inventor: Alexander Kushnarenko
-
Patent number: 6597605Abstract: Systems including a bit sequence program controller to program in sequence non-volatile memory cells in an array of programmable non-volatile memory cells. The bit sequence program controller determines the bits that require programming by comparing the bits of the program word with an erased logical state of the array of programmable non-volatile memory cells. The bit sequence program controller further indicates which non-volatile memory cells in a word of non-volatile memory cells in the array of non-volatile memory cells require programming to match the program word. The bit sequence program controller counts the number of the bits that require programming in the program word by counting the number of bits of the program word that are not in an erased logical state to determine when the programming should be completed.Type: GrantFiled: May 3, 2002Date of Patent: July 22, 2003Assignee: Intel CorporationInventors: Jerry A. Kreifels, Rodney R. Rozman
-
Patent number: 6587376Abstract: A flash memory cell comprises a gate, a drain, a source, a floating gate, and a control gate. The flash memory cell is capable of being programmed by inducing a voltage drop of between about four volts and six volts across a deep-depletion region by applying a first voltage to the gate, a second voltage to the drain, and a third voltage to the source. During a programming operation, the channel current is approximately zero, and the first voltage is ramped at a rate proportional to the injection current.Type: GrantFiled: September 10, 2002Date of Patent: July 1, 2003Assignee: Micron Technology, Inc.Inventors: Andrei Mihnea, Paul J. Rudeck, Chun Chen
-
Patent number: 6580640Abstract: A method and apparatus invention that relates to the reduction of leakage current through a tunnel oxide layer of a memory cell to improve data retention. One method of operating a non-volatile memory cell comprises placing electrons on a floating gate of the memory cell and then placing positive charge on a control gate of the memory cell to improve data retention. The positive charge causes the electrons on the floating gate to migrate away from a tunnel oxide layer of the memory cell. In one embodiment, a Flash memory device comprises a memory array of multiple memory cells. Each memory cell comprises a control gate, a floating gate, an inter-gate dielectric layer positioned between the control gate and the floating gate, a substrate, and a tunnel oxide layer positioned between the floating gate and the substrate.Type: GrantFiled: March 7, 2001Date of Patent: June 17, 2003Assignee: Micron Technology, Inc.Inventor: David Kao
-
Patent number: 6574158Abstract: An approach for testing an erasable programmable read-only memory (EPROM) cell for a threshold voltage is provided. A voltage lower than a source voltage that is associated with a read operation is applied to the gate of the EPROM cell. A signal is read out from the EPROM cell when the voltage is applied to the EPROM cell. The signal is used to calculate the threshold voltage of the EPROM cell.Type: GrantFiled: September 27, 2001Date of Patent: June 3, 2003Assignee: Cypress Semiconductor Corp.Inventor: Sunil Thamaran