Patents Assigned to Saifun Semiconductors Ltd.
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Patent number: 7811887Abstract: Silicon trench isolation (STI) is formed between adjacent diffusions in a semiconductor device, such as between bitlines in a memory array. The STI may be self-aligned to the diffusions, and may prevent misaligned bitline (BL) contacts from contacting silicon outside of the corresponding bitlines. The bitline contacts may have sufficient overlap of the bitlines to ensure full coverage by the bitlines. Bitline oxides formed over buried bitlines may be used to self-align trenches of the STI to the bitlines. The STI trenches may be lined with a CMOS spacer, salicide blocking layer and/or a contact etch stop layer. STI may be formed after Poly-2 etch or after word line salicidation. The memory cells may be NVM devices such as NROM, SONOS, SANOS, MANOS, TANOS or Floating Gate (FG) devices.Type: GrantFiled: November 1, 2007Date of Patent: October 12, 2010Assignee: Saifun Semiconductors Ltd.Inventors: Rustom Irani, Amichai Givant
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Patent number: 7808818Abstract: Secondary electron injection (SEI) is used for programming NVM cells having separate charge storage areas in an ONO layer, such as NROM cells. Various combinations of low wordline voltage (Vwl), negative substrate voltabe (Vb), and shallow and deep implants facilitate the process. Second bit problems may be controlled, and retention and punchthrough may be improved. Lower SEI programming current may result in relaxed constraints on bitine resistance, number of contacts required, and power supply requirements.Type: GrantFiled: December 28, 2006Date of Patent: October 5, 2010Assignee: Saifun Semiconductors Ltd.Inventor: Boaz Eitan
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Patent number: 7804126Abstract: A non-volatile memory array has word lines spaced a sub-F (sub-minimum feature size F) width apart and bit lines generally perpendicular to the word lines. The present invention also includes a method for word-line patterning of a non-volatile memory array which includes generating sub-F word lines from mask generated elements with widths of at least a minimum feature size F.Type: GrantFiled: July 18, 2006Date of Patent: September 28, 2010Assignee: Saifun Semiconductors Ltd.Inventors: Boaz Eitan, Ilan Bloom, Rustom Irani
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Patent number: 7786512Abstract: A non-volatile memory array includes a multiplicity of memory cells, each of whose area is less than 4 F2 per cell (where F is a minimum feature size), and periphery elements to control the memory cells. The present invention also includes a non-volatile memory array which includes word lines and bit lines generally perpendicular to the word lines, with a word line pitch of less than 2 F. In one embodiment, the word lines are made of polysilicon spacers.Type: GrantFiled: July 18, 2006Date of Patent: August 31, 2010Assignee: Saifun Semiconductors Ltd.Inventors: Ilan Bloom, Boaz Eitan, Rustom Irani
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Patent number: 7760554Abstract: 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: GrantFiled: August 2, 2006Date of Patent: July 20, 2010Assignee: Saifun Semiconductors Ltd.Inventors: Boaz Eitan, Natalie Shainsky
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Patent number: 7755938Abstract: Disclosed is a method of reducing the neighbor effect while reading data in a non-volatile memory array. The method includes sensing adjacent memory cells. The sensing of the two adjacent cells is performed substantially simultaneously and through at least a partially shared sensing path.Type: GrantFiled: April 19, 2004Date of Patent: July 13, 2010Assignee: Saifun Semiconductors Ltd.Inventors: Shahar Atir, Oleg Dadashev, Yair Sofer, Eduardo Maayan
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Patent number: 7743230Abstract: A multi-level cell (MLC) memory array may be programmed using a programming circuit having a binary input register to store data to be input into the MLC array and a register to store a programming vector, where each element in the programming vector corresponds to a charge storage region of an MLC in the array. A controller may map pairs of bits from the input register to elements in the programming vector, such that mapping a pair of bits to an element of the programming vector may set the vector element to a “program” value if the pair of bits corresponds to at least one specific program state associated with the programming vector.Type: GrantFiled: February 12, 2007Date of Patent: June 22, 2010Assignee: Saifun Semiconductors Ltd.Inventors: Yan Polansky, Avi Lavan
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Patent number: 7742339Abstract: Selecting a read voltage level for a NVM cell by using an initial value for the read voltage and performing a read operation, comparing an actual number of bits found to an expected number of bits and, if there is a discrepancy between the actual number and the expected number, adjusting the read voltage level, based on variable data such as statistics available, level occupation, neighbor level, previous chunks data, and other data used during read, program or erase. For example, based on a number of missing bits, or upon a result of a previous read operation, or a result obtained at another program level, or upon how many times the memory cell has been cycled, or upon how many memory cells are at each program level, or on a number of bits at another program level in a selected chunk of memory.Type: GrantFiled: January 10, 2007Date of Patent: June 22, 2010Assignee: Saifun Semiconductors Ltd.Inventors: Arik Rizel, Guy Cohen
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Patent number: 7738304Abstract: 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: GrantFiled: October 11, 2005Date of Patent: June 15, 2010Assignee: Saifun Semiconductors Ltd.Inventors: Eduardo Maayan, Boaz Eitan
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Patent number: 7715237Abstract: As part of the present invention, a memory cell may be operated using reference cells having a threshold offset circuit. According to some embodiments of the present invention, a threshold offset value may be determined for a memory cell to be operated based on a location (e.g. memory segment within a memory array) of the memory cell. An input offset circuit of a global reference cell may be adjusted by the threshold offset value for the memory cell; and the memory cell may be operated (e.g. read, written or erased) using the global reference cell whose input offset circuit has been adjusted by the threshold offset value. According to some embodiments of the present invention global reference cells may consist of multiple sets of reference cells, wherein, according to some aspects, each set of the multiple sets of reference cells may be used for operating a different memory array segment.Type: GrantFiled: February 26, 2008Date of Patent: May 11, 2010Assignee: Saifun Semiconductors Ltd.Inventor: Guy Cohen
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Patent number: 7692961Abstract: 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: GrantFiled: August 2, 2006Date of Patent: April 6, 2010Assignee: Saifun Semiconductors Ltd.Inventors: Boaz Eitan, Natalie Shainsky
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Patent number: 7675782Abstract: The present invention is a multi-phase method, circuit and system for programming non-volatile memory (“NVM”) cells in an NVM array. The present invention may include a controller to determine when, during a first programming phase, one or more NVM cells of a first set of cells reaches or exceeds a first intermediate voltage, and to cause a charge pump circuit to apply to a terminal of the one or more cells in the first set second phase programming pulses to induce relatively greater threshold voltage changes in cells having less stored charge than in cells having relatively more stored charge.Type: GrantFiled: October 17, 2006Date of Patent: March 9, 2010Assignee: Saifun Semiconductors Ltd.Inventors: Guy Cohen, Yan Polansky
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Patent number: 7668017Abstract: A method includes determining groups of rows to erase together in order to minimize the margin loss associated with bake after a large number of program and erasure cycles. The method alternatively includes determining groups of rows to erase together to minimize the width of a resultant erase threshold voltage distribution, erasing the groups together, stopping erasure of a group when the group is erase verified and performing the step of erasing on those groups which were not previously erase verified.Type: GrantFiled: August 17, 2005Date of Patent: February 23, 2010Assignee: Saifun Semiconductors Ltd.Inventors: Eli Lusky, Boaz Eitan
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Patent number: 7652930Abstract: The present invention is a method circuit and system for erasing one or more non-volatile memory (“NVM”) cells in an NVM array. One or more NVM cells of a memory array may be erased using an erase pulse produced by a controller and/or erase pulse source adapted to induce and/or invoke a substantially stable channel current in the one or more NVM cells during an erasure procedure. The voltage profile of an erase pulse may be predefined or the voltage profile of the erase pulse may be dynamically adjusted based on feedback from a current sensor during an erase procedure.Type: GrantFiled: April 3, 2005Date of Patent: January 26, 2010Assignee: Saifun Semiconductors Ltd.Inventors: Assaf Shappir, Ilan Bloom, Boaz Eitan
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Patent number: 7638850Abstract: A method for creating a non-volatile memory array includes implanting pocket implants in a substrate at least between mask columns of a given width and at least through an ONO layer covering the substrate, generating increased-width polysilicon columns from the mask columns, generating bit lines in the substrate at least between the increased-width polysilicon columns and depositing oxide at least between the polysilicon columns.Type: GrantFiled: May 24, 2006Date of Patent: December 29, 2009Assignee: Saifun Semiconductors Ltd.Inventors: Eli Lusky, Assaf Shappir, Rustom Irani, Boaz Eitan
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Patent number: 7638835Abstract: An NVM cell such as an NROM cell is formed using a portion of one ONO stack and an adjacent portion of a neighboring NROM stack. A gate structure is formed between (and atop) the two ONO portions, or “strips” (or “stripes”). This provides having two physically separated charge storage regions (nitride “strips”, or “stripes”) in each memory cell.Type: GrantFiled: December 28, 2006Date of Patent: December 29, 2009Assignee: Saifun Semiconductors Ltd.Inventors: Rustom Irani, Boaz Eitan, Ilan Bloom, Assaf Shappir
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Patent number: 7605579Abstract: The present invention is a method and apparatus for regulating current consumption and output current of a charge pump. According to some embodiments of the present invention, a first current coming into the charge pump and a second current coming into a driver of at least one of one or more stages of the charge pump is measured. A control loop may regulate one or more parameters of the charge pump and/or a load connected to the charge pump, such as by adjusting one or more of: a supply voltage; a stage's voltage; the stage's frequency and/or duty-cycle; and the number of stages.Type: GrantFiled: November 21, 2006Date of Patent: October 20, 2009Assignee: Saifun Semiconductors Ltd.Inventors: Yoram Betser, Alexander Kushnarenko, Oleg Dadashev
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Patent number: 7599227Abstract: 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: GrantFiled: April 14, 2008Date of Patent: October 6, 2009Assignee: Saifun Semiconductors Ltd.Inventor: Eduardo Maayan
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Patent number: 7590001Abstract: In certain exemplary embodiments, a memory device with optimized write sectors has a plurality P of memory write sectors and N memory spare sectors Cumulatively, the memory write sectors correspond to the specified storage capacity of the memory. The number N of spares is approximately equal to the number of write sectors expected to be decommissioned within an operational lifetime of the memory, which can be determined by empirical measurement. A method, by way of non-limiting example, of making memory includes specifying a plurality P of write sectors which define a specified storage capacity of a memory device, determining a number N of spare sectors, and making a memory device with about P write sectors and about N spare sectors. The number N can be determined, by way of example, by summing the infant mortality with the random failure of write sectors.Type: GrantFiled: December 18, 2007Date of Patent: September 15, 2009Assignee: Saifun Semiconductors Ltd.Inventor: Meir Janai
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Patent number: 7573745Abstract: 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: GrantFiled: October 31, 2007Date of Patent: August 11, 2009Assignee: Saifun Semiconductors Ltd.Inventors: Eduardo Maayan, Boaz Eitan