Patents by Inventor Luca G. Fasoli

Luca G. 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).

  • Patent number: 7433233
    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: Grant
    Filed: June 18, 2007
    Date of Patent: October 7, 2008
    Assignee: SanDisk 3D LLC
    Inventors: En-Hsing Chen, Andrew J. Walker, Roy E. Scheuerlein, Sucheta Nallamothu, Alper Ilkbahar, Luca G. Fasoli
  • Publication number: 20080238522
    Abstract: Level shift circuits are disclosed for level shifting an input signal corresponding to a first voltage domain, to generate a pair of complementary output signals corresponding to a second, higher-voltage domain. Snap-back sensitive devices in a discharge circuit for a high voltage output node are protected, irrespective of the loading on the output node, and without requiring precise transistor sizing as a function of the output loading. The snap-back sensitive devices are protected by a voltage shifter circuit in series with the sensitive devices, to limit the voltage across the sensitive devices, even for a high capacitance output node at its highest output voltage. The voltage shifter circuit is then bypassed to provide for an output low level that fully reaches the lower power supply rail.
    Type: Application
    Filed: March 31, 2007
    Publication date: October 2, 2008
    Inventors: Tyler J. Thorp, Luca G. Fasoli
  • Publication number: 20080239839
    Abstract: An exemplary amplifier circuit includes a first group of spatially distributed final amplifier stages having a first configuration, and a second group of spatially distributed final amplifier stages having a second configuration different than the first configuration. Both groups share the same control node for their respective final amplifier stages, and both groups share the same amplifier output node. Each group is typically enabled at a time that the other is disabled. In certain embodiments incorporating a memory array, only one critical analog node must be routed throughout the memory array.
    Type: Application
    Filed: March 31, 2007
    Publication date: October 2, 2008
    Inventors: Luca G. Fasoli, Ali K. Al-Shamma, Kenneth K. So
  • Publication number: 20080238541
    Abstract: An exemplary amplifier circuit includes a first group of spatially distributed final amplifier stages having a first configuration, and a second group of spatially distributed final amplifier stages having a second configuration different than the first configuration. Both groups share the same control node for their respective final amplifier stages, and both groups share the same amplifier output node. Each group is typically enabled at a time that the other is disabled. In certain embodiments incorporating a memory array, only one critical analog node must be routed throughout the memory array.
    Type: Application
    Filed: March 31, 2007
    Publication date: October 2, 2008
    Inventors: Luca G. Fasoli, Ali K. Al-Shamma, Kenneth K. So
  • Publication number: 20080238523
    Abstract: Level shift circuits are disclosed for level shifting an input signal corresponding to a first voltage domain, to generate a pair of complementary output signals corresponding to a second, higher-voltage domain. Snap-back sensitive devices in a discharge circuit for a high voltage output node are protected, irrespective of the loading on the output node, and without requiring precise transistor sizing as a function of the output loading. The snap-back sensitive devices are protected by a voltage shifter circuit in series with the sensitive devices, to limit the voltage across the sensitive devices, even for a high capacitance output node at its highest output voltage. The voltage shifter circuit is then bypassed to provide for an output low level that fully reaches the lower power supply rail.
    Type: Application
    Filed: March 31, 2007
    Publication date: October 2, 2008
    Inventors: Tyler J. Thorp, Luca G. Fasoli
  • Patent number: 7420851
    Abstract: Improved circuitry and methods for programming memory cells of a memory device are disclosed. The improved circuitry and methods operate to isolate the memory cells from potentially damaging electrical energy that can be imposed during a precharge phase that precedes programming of the memory cells. Additionally, the improved circuitry and methods can operate to ensure that programming of the memory cells is performed in a controlled manner using only a program current. The improved circuitry and methods are particularly useful for programming non-volatile memory cells. In one embodiment, the memory device pertains to a semiconductor memory product, such as a semiconductor memory chip or a portable memory card.
    Type: Grant
    Filed: October 24, 2006
    Date of Patent: September 2, 2008
    Assignee: San Disk 3D LLC
    Inventor: Luca G. Fasoli
  • Patent number: 7420850
    Abstract: Improved circuitry and methods for programming memory cells of a memory device are disclosed. The improved circuitry and methods operate to isolate the memory cells from potentially damaging electrical energy that can be imposed during a precharge phase that precedes programming of the memory cells. Additionally, the improved circuitry and methods can operate to ensure that programming of the memory cells is performed in a controlled manner using only a program current. The improved circuitry and methods are particularly useful for programming non-volatile memory cells. In one embodiment, the memory device pertains to a semiconductor memory product, such as a semiconductor memory chip or a portable memory card.
    Type: Grant
    Filed: October 24, 2006
    Date of Patent: September 2, 2008
    Assignee: SanDisk 3D LLC
    Inventor: Luca G. Fasoli
  • Publication number: 20080192524
    Abstract: An integrated circuit having a three-dimensional memory array provides for a given number of memory planes, but may be fabricated instead to include a lesser number of memory planes by omitting the masks and processing steps associated with the omitted memory planes, without changing any of the other fabrication masks for the other memory planes or for the remainder of the device, and without requiring routing or other configuration changes to the read or read/write path for the array. Control circuitry for selectively enabling certain layer selector circuits is configurable, and the layer selector circuits are suitably arranged, to couple a respective array line on an implemented memory layer to each respective I/O bus line irrespective of the number of implemented memory planes.
    Type: Application
    Filed: April 14, 2008
    Publication date: August 14, 2008
    Inventors: Luca G. Fasoli, Roy E. Scheuerlein
  • Publication number: 20080159053
    Abstract: A reversible polarity decoder circuit is disclosed which is particularly suitable for implementing a multi-headed decoder structure, such as might be used for decoding word lines, and particularly in a 3D memory array. The decoder circuit provides an overdrive voltage bias to the gates of half-selected word line driver circuits to solidly maintain the half-selected word lines at an inactive level. If the memory array is biased at or near the breakdown voltage, this overdrive voltage may be greater than the breakdown voltage of the decoder transistors. However, in the embodiments described, the decoder circuit accomplishes this without impressing a voltage greater than the breakdown voltage across any of the decoder transistors, for either polarity of operation of the decoder circuit.
    Type: Application
    Filed: December 31, 2006
    Publication date: July 3, 2008
    Inventors: Tianhong Yan, Luca G. Fasoli, Roy E. Scheuerlein
  • Publication number: 20080159052
    Abstract: A reversible polarity decoder circuit is disclosed which is particularly suitable for implementing a multi-headed decoder structure, such as might be used for decoding word lines, and particularly in a 3D memory array. The decoder circuit provides an overdrive voltage bias to the gates of half-selected word line driver circuits to solidly maintain the half-selected word lines at an inactive level. If the memory array is biased at or near the breakdown voltage, this overdrive voltage may be greater than the breakdown voltage of the decoder transistors. However, in the embodiments described, the decoder circuit accomplishes this without impressing a voltage greater than the breakdown voltage across any of the decoder transistors, for either polarity of operation of the decoder circuit.
    Type: Application
    Filed: December 31, 2006
    Publication date: July 3, 2008
    Inventors: Tianhong Yan, Luca G. Fasoli, Roy E. Scheuerlein
  • Patent number: 7391638
    Abstract: Improved circuitry and methods for programming memory cells of a memory device are disclosed. The improved circuitry and methods operate to protect the memory cells from potentially damaging electrical energy that can be imposed during programming of the memory cells. Additionally, the improved circuitry and methods operate to detect when programming of the memory cells has been achieved. The improved circuitry and methods are particularly useful for programming non-volatile memory cells. In one embodiment, the memory device pertains to a semiconductor memory product, such as a semiconductor memory chip or a portable memory card.
    Type: Grant
    Filed: October 24, 2006
    Date of Patent: June 24, 2008
    Assignee: SanDisk 3D LLC
    Inventors: Luca G. Fasoli, Tyler Thorp
  • Patent number: 7383476
    Abstract: In one embodiment, a chip-level architecture is provided comprising a monolithic three-dimensional write-once memory array and at least two of the following system blocks: an Error Checking & Correction Circuit (ECC); a Checkerboard Memory Array containing sub arrays; a Write Controller; a Charge Pump; a Vread Generator; an Oscillator; a Band Gap Reference Generator; and a Page Register/Fault Memory. In another embodiment, a chip-level architecture is provided comprising a monolithic three-dimensional write-once memory array, ECC, and smart write. The monolithic three-dimensional write-once memory array comprises a first conductor, a first memory cell above the first conductor, a second conductor above the first memory cell, and a second memory cell above the second conductor, wherein the second conductor is the only conductor between the first and second memory cells.
    Type: Grant
    Filed: February 9, 2004
    Date of Patent: June 3, 2008
    Assignee: SanDisk 3D LLC
    Inventors: Matthew P. Crowley, Luca G. Fasoli, Alper Ilkbahar, Mark G. Johnson, Bendik Kleveland, Thomas H. Lee, Roy E. Scheuerlein
  • Publication number: 20080094916
    Abstract: Improved circuitry and methods for programming memory cells of a memory device are disclosed. The improved circuitry and methods operate to isolate the memory cells from potentially damaging electrical energy that can be imposed during a precharge phase that precedes programming of the memory cells. Additionally, the improved circuitry and methods can operate to ensure that programming of the memory cells is performed in a controlled manner using only a program current. The improved circuitry and methods are particularly useful for programming non-volatile memory cells. In one embodiment, the memory device pertains to a semiconductor memory product, such as a semiconductor memory chip or a portable memory card.
    Type: Application
    Filed: October 24, 2006
    Publication date: April 24, 2008
    Inventor: Luca G. Fasoli
  • Publication number: 20080094892
    Abstract: Improved circuitry and methods for programming memory cells of a memory device are disclosed. The improved circuitry and methods operate to protect the memory cells from potentially damaging electrical energy that can be imposed during programming of the memory cells. Additionally, the improved circuitry and methods operate to detect when programming of the memory cells has been achieved. The improved circuitry and methods are particularly useful for programming non-volatile memory cells. In one embodiment, the memory device pertains to a semiconductor memory product, such as a semiconductor memory chip or a portable memory card.
    Type: Application
    Filed: October 24, 2006
    Publication date: April 24, 2008
    Inventors: Luca G. Fasoli, Tyler Thorp
  • Publication number: 20080094913
    Abstract: Improved circuitry and methods for programming memory cells of a memory device are disclosed. The improved circuitry and methods operate to protect the memory cells from potentially damaging electrical energy that can be imposed during programming of the memory cells. Additionally, the improved circuitry and methods operate to detect when programming of the memory cells has been achieved. The improved circuitry and methods are particularly useful for programming non-volatile memory cells. In one embodiment, the memory device pertains to a semiconductor memory product, such as a semiconductor memory chip or a portable memory card.
    Type: Application
    Filed: October 24, 2006
    Publication date: April 24, 2008
    Inventors: Luca G. Fasoli, Tyler Thorp
  • Publication number: 20080094915
    Abstract: Improved circuitry and methods for programming memory cells of a memory device are disclosed. The improved circuitry and methods operate to isolate the memory cells from potentially damaging electrical energy that can be imposed during a precharge phase that precedes programming of the memory cells. Additionally, the improved circuitry and methods can operate to ensure that programming of the memory cells is performed in a controlled manner using only a program current. The improved circuitry and methods are particularly useful for programming non-volatile memory cells. In one embodiment, the memory device pertains to a semiconductor memory product, such as a semiconductor memory chip or a portable memory card.
    Type: Application
    Filed: October 24, 2006
    Publication date: April 24, 2008
    Inventor: Luca G. Fasoli
  • Patent number: 7359279
    Abstract: An integrated circuit having a three-dimensional memory array provides for a given number of memory planes, but may be fabricated instead to include a lesser number of memory planes by omitting the masks and processing steps associated with the omitted memory planes, without changing any of the other fabrication masks for the other memory planes or for the remainder of the device, and without requiring routing or other configuration changes to the read or read/write path for the array. Control circuitry for selectively enabling certain layer selector circuits is configurable, and the layer selector circuits are suitably arranged, to couple a respective array line on an implemented memory layer to each respective I/O bus line irrespective of the number of implemented memory planes.
    Type: Grant
    Filed: March 31, 2005
    Date of Patent: April 15, 2008
    Assignee: SanDisk 3D LLC
    Inventors: Luca G. Fasoli, Roy E. Scheuerlein
  • Publication number: 20080025093
    Abstract: Circuits and methods are described for decoding exemplary memory arrays of programmable and, in some embodiments, re-writable passive element memory cells, which are particularly useful for extremely dense three-dimensional memory arrays having more than one memory plane. In addition, circuits and methods are described for selecting one or more array blocks of such a memory array, for selecting one or more word lines and bit lines within selected array blocks, for conveying data information to and from selected memory cells within selected array blocks, and for conveying unselected bias conditions to unselected array blocks.
    Type: Application
    Filed: July 31, 2006
    Publication date: January 31, 2008
    Inventors: Roy E. Scheuerlein, Luca G. Fasoli
  • Publication number: 20080025132
    Abstract: Circuits and methods are described for decoding exemplary memory arrays of programmable and, in some embodiments, re-writable passive element memory cells, which are particularly useful for extremely dense three-dimensional memory arrays having more than one memory plane. In addition, circuits and methods are described for selecting one or more array blocks of such a memory array, for selecting one or more word lines and bit lines within selected array blocks, for conveying data information to and from selected memory cells within selected array blocks, and for conveying unselected bias conditions to unselected array blocks.
    Type: Application
    Filed: July 31, 2006
    Publication date: January 31, 2008
    Inventors: Luca G. Fasoli, Christopher J. Petti, Roy E. Scheuerlein
  • Publication number: 20080025088
    Abstract: A four level passive element cell has memory states corresponding to decreasing resistance levels, which are preferably mapped respectively to data states 11, 01, 00, and 10. The LSB and MSB are preferably mapped as part of different pages. To discriminate between memory cell states, the selected bit line current is sensed for at least two different combinations of reference current level and read bias voltage. A mid-level reference is used to read the LSB. When reading the MSB, a first reference between the 10 and 00 data states, and a second reference between 01 and 11 data states may be used, and the mid-level reference need not be used. In certain embodiments, the bit line current may be simultaneously compared against the first and second references, without requiring a delay to stabilize the bit line current to a different value, and the MSB generated accordingly.
    Type: Application
    Filed: July 31, 2006
    Publication date: January 31, 2008
    Inventors: Roy E. Scheuerlein, Tyler J. Thorp, Luca G. Fasoli