Patents by Inventor Luca Fasoli

Luca Fasoli has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20060083069
    Abstract: A system and method of controlling a three dimensional memory is disclosed. In a particular embodiment, the system is implemented as an integrated circuit including a microcontroller having a control signal output, a three-dimensional monolithic non-volatile memory having a plurality of levels of memory cells above a silicon substrate and having an input responsive to the control signal output, a counter coupled to the microcontroller, and a program memory. The counter is to step through a series of time steps defining a program pulse time interval of a first program pulse to be applied to at least one selected memory cell within the three-dimensional monolithic non-volatile memory. The program memory is accessible to the microcontroller, and the program memory includes a sequence of program instructions corresponding to a memory operation with respect to the three-dimensional monolithic non-volatile memory.
    Type: Application
    Filed: September 30, 2004
    Publication date: April 20, 2006
    Inventor: Luca Fasoli
  • Publication number: 20060067127
    Abstract: A method of programming a monolithic three-dimensional (3-D) memory having a plurality of levels of memory cells above a silicon substrate is disclosed. The method includes initializing a program voltage and program time interval; selecting a memory cell to be programmed within the three-dimensional memory having the plurality of levels of memory cells; applying a pulse having the program voltage and the program time interval to the selected memory cell; performing a read after write operation with respect to the selected memory cell to determine a measured threshold voltage value; and comparing the measured threshold voltage value to a minimum program voltage. In response to the comparison between the measured threshold voltage value and the minimum program voltage, the method further includes selectively applying at least one subsequent program pulse to the selected memory cell.
    Type: Application
    Filed: September 30, 2004
    Publication date: March 30, 2006
    Inventors: Luca Fasoli, Roy Scheuerlein, Alper Ilkbahar, En-Hsing Chen, Tanmay Kumar
  • Patent number: 7005350
    Abstract: A three-dimensional flash memory array incorporates thin film transistors having a charge storage dielectric arranged in series-connected NAND strings to achieve a 4F2 memory cell layout. The memory array may be programmed and erased using only tunneling currents, and no leakage paths are formed through non-selected memory cells. Each NAND string includes two block select devices for respectively coupling one end of the NAND string to a global bit line, and the other end to a shared bias node. Pairs of NAND strings within a block share the same global bit line. The memory cells are preferably depletion mode SONOS devices, as are the block select devices. The memory cells may be programmed to a near depletion threshold voltage, and the block select devices are maintained in a programmed state having a near depletion mode threshold voltage. NAND strings on more than one layer may be connected to global bit lines on a single layer.
    Type: Grant
    Filed: December 31, 2002
    Date of Patent: February 28, 2006
    Assignee: Matrix Semiconductor, Inc.
    Inventors: Andrew J. Walker, En-Hsing Chen, Sucheta Nallamothu, Roy E. Scheuerlein, Alper Ilkbahar, Luca Fasoli, Igor Koutnetsov, Christopher Petti
  • Publication number: 20050128807
    Abstract: An exemplary NAND string memory array provides for capacitive boosting of a half-selected memory cell channel to reduce program disturb effects of the half selected cell. To reduce the effect of leakage current degradation of the boosted level, multiple programming pulses of a shorter duration are employed to limit the time period during which such leakage currents may degrade the voltage within the unselected NAND strings. In addition, multiple series select devices at one or both ends of each NAND string further ensure reduced leakage through such select devices, for both unselected and selected NAND strings. In certain exemplary embodiments, a memory array includes series-connected NAND strings of memory cell transistors having a charge storage dielectric, and includes more than one plane of memory cells formed above a substrate.
    Type: Application
    Filed: December 5, 2003
    Publication date: June 16, 2005
    Inventors: En-Hsing Chen, Andrew Walker, Roy Scheuerlein, Sucheta Nallamothu, Alper Ilkbahar, Luca Fasoli, James Cleeves
  • Publication number: 20050122780
    Abstract: An exemplary NAND string memory array provides for capacitive boosting of a half-selected memory cell channel to reduce program disturb effects of the half selected cell. To reduce the effect of leakage current degradation of the boosted level, multiple programming pulses of a shorter duration are employed to limit the time period during which such leakage currents may degrade the voltage within the unselected NAND strings. In addition, multiple series select devices at one or both ends of each NAND string further ensure reduced leakage through such select devices, for both unselected and selected NAND strings. In certain exemplary embodiments, a memory array includes series-connected NAND strings of memory cell transistors having a charge storage dielectric, and includes more than one plane of memory cells formed above a substrate.
    Type: Application
    Filed: December 5, 2003
    Publication date: June 9, 2005
    Inventors: En-Hsing Chen, Andrew Walker, Roy Scheuerlein, Sucheta Nallamothu, Alper Ilkbahar, Luca Fasoli
  • Publication number: 20050122779
    Abstract: An exemplary NAND string memory array includes at least one plane of memory cells, said memory cells comprising thin film modifiable conductance switch devices and which cells are arranged in a plurality of series-connected NAND strings, and NAND strings including a series select device at each end thereof. Another exemplary NAND string memory array includes a group of more than four adjacent NAND strings within the same memory block each associated with a respective global bit line not shared by the other NAND string of the group. Another exemplary NAND string memory array includes NAND strings on identical pitch as their respective global bit lines.
    Type: Application
    Filed: December 5, 2003
    Publication date: June 9, 2005
    Inventors: Luca Fasoli, Roy Scheuerlein, En-Hsing Chen, Sucheta Nallamothu, Maitreyee Mahajani, Andrew Walker
  • Publication number: 20050078514
    Abstract: Extremely dense memory cell structures provide for new array structures useful for implementing memory and logic functions. An exemplary non-volatile memory array includes a first plurality of X-lines configured to be logically identical in a read mode of operation, and each associated with a first Y-line group numbering at least one Y-line. Each of the first plurality of X-lines may also be associated with a second Y-line group numbering at least one Y-line. In some embodiments, the first and second Y-Line groups are simultaneously selectable in a read mode and, when so selected, are respectively coupled to true and complement inputs of a sense amplifier circuit. Such Y-line groups may number only one Y-line, or may number more than one Y-line. Many types of memory cells may be used, such as various passive element cells and EEPROM cells, in both 2D or 3D memory arrays.
    Type: Application
    Filed: September 30, 2003
    Publication date: April 14, 2005
    Inventors: Roy Scheuerlein, Luca Fasoli, Mark Johnson
  • Publication number: 20050079675
    Abstract: An array of transistors includes a plurality of transistors, a plurality of word lines extending in a first direction and a plurality of bit lines extending in a second direction. Each transistor includes a source, a drain, a channel and a localized charge storage dielectric. A first transistor of the plurality of transistors and a second transistor of the plurality of transistors share a common source/drain. A first localized charge storage dielectric of the first transistor does not overlap the common source/drain and a second localized charge storage dielectric of the second transistor overlaps the common source/drain.
    Type: Application
    Filed: October 18, 2004
    Publication date: April 14, 2005
    Inventors: Alper Ilkbahar, Roy Scheuerlein, Andrew Walker, Luca Fasoli
  • Publication number: 20050078537
    Abstract: The preferred embodiments described herein relate to a method and system for temperature compensation for memory cells with temperature-dependent behavior. In one preferred embodiment, at least one of a first temperature-dependent reference voltage comprising a negative temperature coefficient and a second temperature-dependent reference voltage comprising a positive temperature coefficient is generated. One of a wordline voltage and a bitline voltage is generated from one of the at least one of the first and second temperature-dependent reference voltages. The other of the wordline and bitline voltages is generated, and the wordline and bitline voltages are applied across a memory cell. Other methods and systems are disclosed for sensing a memory cell comprising temperature-dependent behavior, and each of the preferred embodiments can be used alone or in combination with one another.
    Type: Application
    Filed: September 30, 2003
    Publication date: April 14, 2005
    Inventors: Kenneth So, Luca Fasoli, Bendik Kleveland
  • Patent number: 6849905
    Abstract: An array of transistors includes a plurality of transistors, a plurality of word lines extending in a first direction and a plurality of bit lines extending in a second direction. Each transistor includes a source, a drain, a channel and a localized charge storage dielectric. A first transistor of the plurality of transistors and a second transistor of the plurality of transistors share a common source/drain. A first localized charge storage dielectric of the first transistor does not overlap the common source/drain and a second localized charge storage dielectric of the second transistor overlaps the common source/drain.
    Type: Grant
    Filed: December 23, 2002
    Date of Patent: February 1, 2005
    Assignee: Matrix Semiconductor, Inc.
    Inventors: Alper Ilkbahar, Roy Scheuerlein, Andrew J. Walker, Luca Fasoli
  • Patent number: 6807119
    Abstract: An array of transistors includes a plurality of charge storage transistors and a plurality of dummy transistors interspersed with the plurality of charge storage transistors. Each of the plurality of the dummy transistors is made using the same photolithographic masking steps as each of the plurality of the charge storage transistors. A method of operating the array includes programming and/or erasing the array of transistors, and reading the plurality of charge storage transistors but not the plurality of dummy transistors.
    Type: Grant
    Filed: December 23, 2002
    Date of Patent: October 19, 2004
    Assignee: Matrix Semiconductor, Inc.
    Inventors: Luca Fasoli, Alper Ilkbahar, Roy Scheuerlein
  • Publication number: 20040188714
    Abstract: A three-dimensional (3D) high density memory array includes multiple layers of segmented bit lines (i.e., sense lines) with segment switch devices within the memory array that connect the segments to global bit lines. The segment switch devices reside on one or more layers of the integrated circuit, preferably residing on each bit line layer. The global bit lines reside preferably on one layer below the memory array, but may reside on more than one layer. The bit line segments preferably share vertical connections to an associated global bit line. In certain EEPROM embodiments, the array includes multiple layers of segmented bit lines with segment connection switches on multiple layers and shared vertical connections to a global bit line layer. Such memory arrays may be realized with much less write-disturb effects for half selected memory cells, and may be realized with a much smaller block of cells to be erased.
    Type: Application
    Filed: March 31, 2003
    Publication date: September 30, 2004
    Inventors: Roy E. Scheuerlein, Alper Ilkbahar, Luca Fasoli
  • Publication number: 20040124466
    Abstract: A three-dimensional flash memory array incorporates thin film transistors having a charge storage dielectric arranged in series-connected NAND strings to achieve a 4F2 memory cell layout. The memory array may be programmed and erased using only tunneling currents, and no leakage paths are formed through non-selected memory cells. Each NAND string includes two block select devices for respectively coupling one end of the NAND string to a global bit line, and the other end to a shared bias node. Pairs of NAND strings within a block share the same global bit line. The memory cells are preferably depletion mode SONOS devices, as are the block select devices. The memory cells may be programmed to a near depletion threshold voltage, and the block select devices are maintained in a programmed state having a near depletion mode threshold voltage. NAND strings on more than one layer may be connected to global bit lines on a single layer.
    Type: Application
    Filed: December 31, 2002
    Publication date: July 1, 2004
    Inventors: Andrew J. Walker, En-Hsing Chen, Sucheta Nallamothu, Roy E. Scheuerlein, Alper Ilkbahar, Luca Fasoli, Igor Kouznetsov, Christopher Petti
  • Publication number: 20040125629
    Abstract: A three-dimensional flash memory array incorporates thin film transistors having a charge storage dielectric arranged in series-connected NAND strings to achieve a 4F2 memory cell layout. The memory array may be programmed and erased using only tunneling currents, and no leakage paths are formed through non-selected memory cells. Each NAND string includes two block select devices for respectively coupling one end of the NAND string to a global bit line, and the other end to a shared bias node. Pairs of NAND strings within a block share the same global bit line. The memory cells are preferably depletion mode SONOS devices, as are the block select devices. The memory cells may be programmed to a near depletion threshold voltage, and the block select devices are maintained in a programmed state having a near depletion mode threshold voltage. NAND strings on more than one layer may be connected to global bit lines on a single layer.
    Type: Application
    Filed: December 31, 2002
    Publication date: July 1, 2004
    Inventors: Roy E. Scheuerlein, Christopher Petti, Andrew J. Walker, En-Hsing Chen, Sucheta Nallamothu, Alper Ilkbahar, Luca Fasoli, Igor Kouznetsov
  • Publication number: 20040120186
    Abstract: An array of transistors includes a plurality of charge storage transistors and a plurality of dummy transistors interspersed with the plurality of charge storage transistors. Each of the plurality of the dummy transistors is made using the same photolithographic masking steps as each of the plurality of the charge storage transistors. A method of operating the array includes programming and/or erasing the array of transistors, and reading the plurality of charge storage transistors but not the plurality of dummy transistors.
    Type: Application
    Filed: December 23, 2002
    Publication date: June 24, 2004
    Inventors: Luca Fasoli, Alper Ilkbahar, Roy Scheuerlein
  • Publication number: 20040119122
    Abstract: An array of transistors includes a plurality of transistors, a plurality of word lines extending in a first direction and a plurality of bit lines extending in a second direction. Each transistor includes a source, a drain, a channel and a localized charge storage dielectric. A first transistor of the plurality of transistors and a second transistor of the plurality of transistors share a common source/drain. A first localized charge storage dielectric of the first transistor does not overlap the common source/drain and a second localized charge storage dielectric of the second transistor overlaps the common source/drain.
    Type: Application
    Filed: December 23, 2002
    Publication date: June 24, 2004
    Inventors: Alper Ilkbahar, Roy Scheuerlein, Andrew J. Walker, Luca Fasoli