Patents Assigned to Saifun Semiconductors Ltd.
  • Patent number: 7535765
    Abstract: A non-volatile device and method of operating the device including changing a read reference level for reading a group of memory cells as a function of changes in a threshold voltage distribution of a different group of memory cells. The changing step may include determining a history read reference level of a history cell associated with a group of memory cells of a non-volatile memory cell array and comparing sensed logical state distributions with stored logical state distributions.
    Type: Grant
    Filed: July 10, 2007
    Date of Patent: May 19, 2009
    Assignee: Saifun Semiconductors Ltd.
    Inventor: Eduardo Maayan
  • Patent number: 7532529
    Abstract: A method for sensing a signal received from an array cell within a memory array, the method comprising the steps of generating an analog voltage Vddr proportional to a current of a selected array cell of the memory array, and comparing the analog voltage Vddr with a reference analog voltage Vcomp to generate an output digital signal. A method is also provided for sensing a memory cell by transforming a signal from a memory cell to a time delay, and sensing the memory cell by comparing the time delay to a time delay of a reference cell. Related apparatus is also disclosed.
    Type: Grant
    Filed: August 14, 2006
    Date of Patent: May 12, 2009
    Assignee: Saifun Semiconductors Ltd.
    Inventors: Oleg Dadashev, Yoram Betser, Eduardo Maayan
  • Patent number: 7518908
    Abstract: A method for operating an electrically erasable programmable read only memory (EEPROM) array includes providing an array including a multiplicity of memory cells, wherein each memory cell is connected to a word line and to two bit lines, selecting one of the memory cells, and erasing a bit of the selected memory cell while applying an inhibit word line voltage to a gate of an unselected memory cell. An EEPROM array is also described, the array including a multiplicity of NROM memory cells, wherein each memory cell is connected to a word line and to two bit lines, and wherein each NROM cell is individually erasable and individually programmable without significantly disturbing unselected cells.
    Type: Grant
    Filed: May 28, 2002
    Date of Patent: April 14, 2009
    Assignee: Saifun Semiconductors Ltd.
    Inventors: Eduardo Maayan, Ron Eliyahu, Boaz Eitan
  • Patent number: 7512009
    Abstract: A method for programming one or more reference cells is described. The reference cell is programmed a predetermined amount, its program state is sensed relative to a prescribed cell on the same die (e.g., a memory cell or a golden bit cell), and the programming process continues until the reference cell fails a preselected read operation. In one preferred embodiment, the memory cell used during the reference cell programming process is the cell in the memory array having the highest native threshold value. In another preferred embodiment, the memory cell used during the reference cell programming process is a native cell that is on-board the die containing the memory array, but not a cell within the memory array.
    Type: Grant
    Filed: April 27, 2006
    Date of Patent: March 31, 2009
    Assignee: Saifun Semiconductors Ltd.
    Inventors: Eduardo Maayan, Ron Eliyahu, Ameet Lann, Boaz Eitan
  • Patent number: 7489562
    Abstract: A die for a memory array may store Flash and EEPROM bits in at least one Nitride Read Only Memory (NROM) array. Each array may store Flash, EEPROM or both types of bits.
    Type: Grant
    Filed: October 31, 2007
    Date of Patent: February 10, 2009
    Assignee: Saifun Semiconductors Ltd.
    Inventors: Eduardo Maayan, Boaz Eitan
  • Patent number: 7468926
    Abstract: A method for erasing memory cells in a memory array, the method including applying an erase pulse to bits of a cell ensemble of a memory cell array, and performing an erase verification operation only on a subgroup of the cell ensemble being erased to check if the memory cells threshold voltage (Vt) has been lowered to an erase verify (EV) voltage level.
    Type: Grant
    Filed: January 19, 2006
    Date of Patent: December 23, 2008
    Assignee: Saifun Semiconductors Ltd.
    Inventors: Assaf Shappir, Shai Eisen
  • Patent number: 7466594
    Abstract: A method for operating a non-volatile memory cell device, the method including providing an array of memory array cells connected to word lines and local bit lines, the local bit lines being connected to global bit lines via select transistors, the array being divided into isolated sectors, providing a sense amplifier operative to sense the memory array cells via a sensing path that includes at least one of the local bit lines, at least one of the select transistors, at least one accessed global bit line, and a YMUX, providing a reference cell located in a reference mini-array, the reference cell being connected to the YMUX and being connected to the sense amplifier via another sensing path, driving both the memory array cells and the reference cells with a common bit line (BL) driver connected to the memory array cells and the reference cells via the YMUX through accessed global bit lines, and matching the sensing path of the memory array cell and the sensing path of the reference cell to the sense amplifier
    Type: Grant
    Filed: July 19, 2006
    Date of Patent: December 16, 2008
    Assignee: Saifun Semiconductors Ltd.
    Inventors: Yair Sofer, Eduardo Maayan, Yoram Betser
  • Patent number: 7457183
    Abstract: A method for reading a bit of a memory cell in a non-volatile memory (NVM) cell array, the method comprising providing a memory cell comprising a bit to be read and at least one other bit not to be read, and reading the bit to be read with respect to a multi-bit reference cell, the reference cell comprising a first bit at a first non-ground programmed state and a second bit at a second non-ground programmed state. Compared with the prior art, the present invention may enable achieving an improved sensing accuracy together with improved read disturb immunity.
    Type: Grant
    Filed: October 16, 2006
    Date of Patent: November 25, 2008
    Assignee: Saifun Semiconductors Ltd.
    Inventors: Eli Lusky, Boaz Eitan, Guy Cohen, Eduardo Maayan
  • Patent number: 7420848
    Abstract: A method and a system for operating bits of memory cells in a memory array, the method including applying a first operating pulse to a terminal of a first cell, the first operating pulse is intended to place the first cell into a predefined state; and applying a second operating pulse to a terminal of a second cell in the set, the second operating pulse is intended to place the second cell to the predefined state, and the pulse characteristics of the second operating pulse are a function of the response of the first cell to the first operating pulse.
    Type: Grant
    Filed: January 9, 2006
    Date of Patent: September 2, 2008
    Assignee: Saifun Semiconductors Ltd.
    Inventors: Assaf Shappir, Dror Avni, Boaz Eitan
  • 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
  • Patent number: 7400529
    Abstract: A non-volatile electrically erasable programmable read only memory (EEPROM) capable of storing two bit of information having a non-conducting 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 non-conducting 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: April 17, 2007
    Date of Patent: July 15, 2008
    Assignee: Saifun Semiconductors Ltd.
    Inventors: Boaz Eitan, Eduardo Maayan
  • Patent number: 7369440
    Abstract: The present invention is a method, circuit and system for erasing one or more non-volatile memory (“NVM”) cells in an NVM array or array segment. According to some embodiments of the present invention, one or more erase pulse parameters may be associated with each of a number of array segments within an NVM array. Separate erase pulse parameters may be associated with anywhere from one to all of the array segments within an NVM array. According to some embodiments of the present invention, a characteristic of an erase pulse (e.g. pulse amplitude, pulse duration, etc.) applied to one or more NVM cells within an array segment may be at least partially based on one or more erase pulse parameters associated with the given array segment.
    Type: Grant
    Filed: January 19, 2006
    Date of Patent: May 6, 2008
    Assignee: Saifun Semiconductors Ltd.
    Inventors: Assaf Shappir, Shai Eisen
  • Patent number: 7366025
    Abstract: Methods for minimizing current consumption in a memory array during programming of non-volatile memory cells, such as NROM cells, in the array include: programming a cell without having a direct current flowing from a positive supply to ground through the array, programming a plurality of cells with programming pulses without discharging a global bit line carrying a programming voltage between programming pulses, and programming a cell with transient currents.
    Type: Grant
    Filed: June 10, 2004
    Date of Patent: April 29, 2008
    Assignee: Saifun Semiconductors Ltd.
    Inventor: Eduardo Maayan
  • Patent number: 7339826
    Abstract: An NROM (nitride read only memory) cell, which is programmed by channel hot electron injection and erased by hot hole injection, includes a charge trapping structure formed of: a bottom oxide layer, a charge trapping layer; and a top oxide layer. The bottom oxide layer is no thicker than that which provides margin stability.
    Type: Grant
    Filed: April 11, 2005
    Date of Patent: March 4, 2008
    Assignee: Saifun Semiconductors Ltd.
    Inventor: Eli Lusky
  • Patent number: 7317633
    Abstract: A method for protecting NROM devices from charge damage during process steps, the method including providing X-decoder structure for word line connections, wherein each word line is connected to a pair of transistors, a PMOS transistor and an NMOS transistor the PMOS transistors sharing a common deep N well and the NMOS transistors connected to a P well, wherein during negative charging, the NMOS transistors shunt leakage current to ground, and during positive charging, the PMOS transistors shunt leakage current to ground, providing an N+ tap connected to the N well and connecting the N+ tap to a positive voltage clamping device, and connecting all the P wells together to a common P+ tap and connecting the P+ tap to a negative voltage clamping device, wherein during process steps, the negative and positive voltage clamping devices direct leakage current to ground.
    Type: Grant
    Filed: July 5, 2005
    Date of Patent: January 8, 2008
    Assignee: Saifun Semiconductors Ltd
    Inventors: Eli Lusky, Ilan Bloom, Assaf Shappir, Boaz Eitan
  • Publication number: 20070195607
    Abstract: Operating NVM memory cell such as an NROM cell by using a combination of Fowler-Nordheim tunneling (FNT), hot hole injection (HHI), and channel hot electron (CHE) injection. In the FNT erase step, only a few cells may be verified, and in the CHE second programming step, the threshold voltage of those cells which were not fully erased in the FNT erase step is increased to a high threshold voltage level (ERS state).
    Type: Application
    Filed: August 2, 2006
    Publication date: August 23, 2007
    Applicant: Saifun Semiconductors Ltd.
    Inventors: Boaz Eitan, Natalie Shainsky
  • Publication number: 20070196982
    Abstract: Programming a NVM memory cell such as an NROM cell by using hot hole injection (HHI), followed by channel hot electron (CHE) injection. CHE injection increases the threshold voltage (Vt) of bits of memory cells that were disturbed (unnecessarily programmed) in HHI programming step. Page Write may be performed using a combination of only HHI, followed by CHE without any Erase.
    Type: Application
    Filed: August 2, 2006
    Publication date: August 23, 2007
    Applicant: Saifun Semiconductors Ltd.
    Inventor: Boaz Eitan
  • Patent number: 7256438
    Abstract: A capacitor including a first active layer capacitively coupled to a second active layer, the second active layer being capacitively coupled to a third layer, the third layer being capacitively coupled to a fourth layer, wherein an anode of the capacitor is connected to one of the first and second active layers, and a cathode of the capacitor is connected to the other one of the first and second active layers, and wherein the third layer is left floating. The fourth layer may be connected to a supply voltage, such as but not limited to, ground.
    Type: Grant
    Filed: June 8, 2004
    Date of Patent: August 14, 2007
    Assignee: Saifun Semiconductors Ltd
    Inventors: Joseph S. Shor, Eduardo Maayan, Yoram Betser
  • Patent number: 7257025
    Abstract: A method includes changing a read reference level for reading a group of memory cells as a function of changes in a threshold voltage distribution of a different group of memory cells. The changing step includes determining a history read reference level for correct reading of at least one history cell, selecting a memory read reference level according to the first read reference level, and reading non-volatile memory array cells associated with the at least one history cell using the memory read reference level.
    Type: Grant
    Filed: December 9, 2004
    Date of Patent: August 14, 2007
    Assignee: Saifun Semiconductors Ltd
    Inventors: Eduardo Maayan, Guy Cohen, Boaz Eitan
  • Publication number: 20070173017
    Abstract: A method for creating a non-volatile memory array includes generating removable mask columns to define bit lines, implanting bit lines into the substrate at least between the columns, depositing oxide filler over the bit lines, removing the mask columns, depositing a polysilicon layer over the array and etching the polysilicon layer into word lines. The polysilicon extends at least into spaces left behind by the removed mask columns. The method also includes performing a dual work integration doping after the word line patterning.
    Type: Application
    Filed: January 20, 2006
    Publication date: July 26, 2007
    Applicant: Saifun Semiconductors, Ltd.
    Inventors: Boaz Eitan, Eli Lusky