Patents by Inventor Andrei Mihnea

Andrei Mihnea 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: 20120300551
    Abstract: Embodiments of the present disclosure provide methods, devices, modules, and systems for healing non-volatile memory cells. One method includes biasing a first select gate transistor coupled to a string of memory cells at a first voltage, biasing a second select gate transistor coupled to the string at a second voltage, applying a first healing voltage to a first edge word line in order to extract charge accumulated between the first select gate transistor and a first edge memory cell stack of the string, and applying a second healing voltage to a second edge word line in order to extract charge accumulated between the second select gate transistor and a second edge memory cell stack of the string.
    Type: Application
    Filed: August 6, 2012
    Publication date: November 29, 2012
    Applicant: MICRON TECHNOLOGY, INC.
    Inventors: Andrei Mihnea, William Kueber, Mark Helm
  • Publication number: 20120302029
    Abstract: A storage system and method for forming a storage system that uses punch-through diodes as a steering element in series with a reversible resistivity-switching element is described. The punch-through diode allows bipolar operation of a cross-point memory array. The punch-through diode may have a symmetrical non-linear current/voltage relationship. The punch-through diode has a high current at high bias for selected cells and a low leakage current at low bias for unselected cells. Therefore, it is compatible with bipolar switching in cross-point memory arrays having resistive switching elements. The punch-through diode may be a N+/P?/N+ device or a P+/N?/P+ device.
    Type: Application
    Filed: August 9, 2012
    Publication date: November 29, 2012
    Inventors: Andrei Mihnea, Deepak C. Sekar, George Samachisa, Roy Scheuerlein, Li Xiao
  • Patent number: 8274130
    Abstract: A storage system and method for forming a storage system that uses punch-through diodes as a steering element in series with a reversible resistivity-switching element is described. The punch-through diode allows bipolar operation of a cross-point memory array. The punch-through diode may have a symmetrical non-linear current/voltage relationship. The punch-through diode has a high current at high bias for selected cells and a low leakage current at low bias for unselected cells. Therefore, it is compatible with bipolar switching in cross-point memory arrays having resistive switching elements. The punch-through diode may be a N+/P?/N+ device or a P+/N?/P+ device.
    Type: Grant
    Filed: October 20, 2009
    Date of Patent: September 25, 2012
    Assignee: SanDisk 3D LLC
    Inventors: Andrei Mihnea, Deepak C. Sekar, George Samachisa, Roy Scheuerlein, Li Xiao
  • Patent number: 8264885
    Abstract: Embodiments of the present disclosure provide methods, devices, modules, and systems for operating memory cells. One method includes: performing an erase operation on a selected group of memory cells, the selected group including a number of reference cells and a number of data cells; performing a programming monitor operation on the number of reference cells as part of the erase operation; and determining a number of particular operating parameters associated with operating the number of data cells at least partially based on the programming monitor operation performed on the number of reference cells.
    Type: Grant
    Filed: April 8, 2011
    Date of Patent: September 11, 2012
    Assignee: Micron Technology, Inc.
    Inventors: Akira Goda, Andrei Mihnea
  • Patent number: 8238170
    Abstract: Embodiments of the present disclosure provide methods, devices, modules, and systems for healing non-volatile memory cells. One method includes biasing a first select gate transistor coupled to a string of memory cells at a first voltage, biasing a second select gate transistor coupled to the string at a second voltage, applying a first healing voltage to a first edge word line in order to extract charge accumulated between the first select gate transistor and a first edge memory cell stack of the string, and applying a second healing voltage to a second edge word line in order to extract charge accumulated between the second select gate transistor and a second edge memory cell stack of the string.
    Type: Grant
    Filed: March 10, 2010
    Date of Patent: August 7, 2012
    Assignee: Micron Technology, Inc.
    Inventors: Andrei Mihnea, William Kueber, Mark Helm
  • Publication number: 20120176831
    Abstract: A memory cell in a 3-D read and write memory device has two bipolar resistance-switching layers with different respective switching currents. A low current resistance-switching layer can be switched in set and reset processes while a high current resistance-switching layer remains in a reset state and acts as a protection resistor to prevent excessively high currents on the low current resistance-switching layer. The low and high current resistance-switching layers can be of the same material such as a metal oxide, where the layers differ in terms of thickness, doping, leakiness, metal richness or other variables. Or, the low and high current resistance-switching layers can be of different materials, having one or more layers each. The high current resistance-switching layer can have a switching current which is greater than a switching current of the low current resistance-switching layer by a factor of at least 1.5 or 2.0, for instance.
    Type: Application
    Filed: March 19, 2012
    Publication date: July 12, 2012
    Inventors: Li Xiao, Chandu Gorla, Abhijit Bandyopadhyay, Andrei Mihnea
  • Publication number: 20120145984
    Abstract: A punch-through diode and method of fabricating the same are disclosed herein. The punch-through diode may be used as a steering element in a memory device having a reversible resistivity-switching element. For example, a memory cell may include a reversible resistivity-switching element in series with a punch-through diode. The punch-through diode allows bipolar operation of a cross-point memory array. The punch-through diode may have a symmetrical non-linear current/voltage relationship. The punch-through diode has a high current at high bias for selected cells and a low leakage current at low bias for unselected cells. In other words, the ratio of Ion/Ioff is high. Therefore, the punch-through diode is compatible with bipolar switching in cross-point memory arrays having resistive switching elements.
    Type: Application
    Filed: December 13, 2010
    Publication date: June 14, 2012
    Inventors: Peter Rabkin, Andrei Mihnea
  • Publication number: 20120120709
    Abstract: A nonvolatile memory device with a first conductor extending in a first direction and a semiconductor element above the first conductor. The semiconductor element includes a source, a drain and a channel of a field effect transistor (JFET or MOSFET). The nonvolatile memory device also includes a second conductor above the semiconductor element, the second conductor extending in a second direction. The nonvolatile memory device also includes a resistivity switching material disposed between the first conductor and the semiconductor element or between the second conductor and the semiconductor element. The JFET or MOSFET includes a gate adjacent to the channel, and the MOSFET gate being self-aligned with the first conductor.
    Type: Application
    Filed: November 16, 2010
    Publication date: May 17, 2012
    Applicant: SanDisk 3D LLC
    Inventors: Andrei Mihnea, George Samachisa
  • Publication number: 20120091419
    Abstract: In some embodiments, a memory cell is provided that includes a storage element formed from an MIM stack including (1) a first conductive layer; (2) an RRS layer formed above the first conductive layer; and (3) a second conductive layer formed above the RRS layer, at least one of the first and second conductive layers comprising a first semiconductor material layer. The memory cell includes a steering element coupled to the storage element, the steering element formed from the first semiconductor material layer of the MIM stack and one or more additional material layers. Numerous other aspects are provided.
    Type: Application
    Filed: October 14, 2010
    Publication date: April 19, 2012
    Inventors: Yung-Tin Chen, Chuanbin Pan, Andrei Mihnea, Steven Maxell, Kun Hou
  • Publication number: 20120091427
    Abstract: In some embodiments, a memory array is provided that includes (1) a first memory cell having (a) a first conductive line; (b) a first bipolar storage element formed above the first conductive line; and (c) a second conductive line formed above the first bipolar storage element; and (2) a second memory cell formed above the first memory cell and having (a) a second bipolar storage element formed above the second conductive line; and (b) a third conductive line formed above the second bipolar storage element. The first and second memory cells share the second conductive line; the first bipolar storage element has a first storage element polarity orientation within the first memory cell; the second bipolar storage element has a second storage element polarity orientation within the second memory cell; and the second storage element polarity orientation is opposite the first storage element polarity orientation. Numerous other aspects are provided.
    Type: Application
    Filed: October 14, 2010
    Publication date: April 19, 2012
    Inventors: Yung-Tin Chen, Andrei Mihnea, Roy E. Scheuerlein, Luca Fasoli
  • Patent number: 8139421
    Abstract: Methods for erasing a memory device and memory systems are provided, such as those including a non-volatile memory device is erased by using an intermediate erase step prior to a normal erase step. The intermediate erase step is comprised of an erase pulse voltage, applied to the semiconductor well of the selected memory block of memory cells, while edge rows of memory cells are biased at a low positive voltage (e.g., 0.2-2V). An erase verify operation is then performed. If the selected memory block is not erased, a normal memory erase step is then performed in which the same erase pulse voltage is used but all of the rows are biased at ground potential as in a normal erase step. If the memory block is still fails the erase verify operation, the erase pulse voltage is increased and the process repeated.
    Type: Grant
    Filed: October 18, 2010
    Date of Patent: March 20, 2012
    Assignee: Micron Technology, Inc.
    Inventors: Andrei Mihnea, William Kueber
  • Publication number: 20110280076
    Abstract: A non-volatile memory device includes at least one junctionless transistor and a storage region. The junctionless transistor includes a junctionless, heavily doped semiconductor channel having two dimensions less than 100 nm.
    Type: Application
    Filed: August 2, 2010
    Publication date: November 17, 2011
    Applicant: SanDisk Corporation
    Inventors: George Samachisa, Johann Alsmeier, Andrei Mihnea
  • Publication number: 20110188312
    Abstract: Embodiments of the present disclosure provide methods, devices, modules, and systems for operating memory cells. One method includes: performing an erase operation on a selected group of memory cells, the selected group including a number of reference cells and a number of data cells; performing a programming monitor operation on the number of reference cells as part of the erase operation; and determining a number of particular operating parameters associated with operating the number of data cells at least partially based on the programming monitor operation performed on the number of reference cells.
    Type: Application
    Filed: April 8, 2011
    Publication date: August 4, 2011
    Applicant: MICRON TECHNOLOGY, INC.
    Inventors: Akira Goda, Andrei Mihnea
  • Patent number: 7986555
    Abstract: A nitride read only memory (NROM) cell can be programmed by applying a ramp voltage to the gate input, a constant voltage to one of the two source/drain regions, and a ground potential to the remaining source/drain region. In order to erase the NROM cell, a constant voltage is coupled to the gate input. A constant positive current is input to one of the source/drain regions. The remaining source/drain region is either allowed to float, is coupled to a ground potential, or is coupled to the first source/drain region.
    Type: Grant
    Filed: November 20, 2009
    Date of Patent: July 26, 2011
    Assignee: Micron Technology, Inc.
    Inventor: Andrei Mihnea
  • Publication number: 20110140064
    Abstract: A carbon/tunneling-barrier/carbon diode and method for forming the same are disclosed. The carbon/tunneling-barrier/carbon may be used as a steering element in a memory array. Each memory cell in the memory array may include a reversible resistivity-switching element and a carbon/tunneling-barrier/carbon diode as the steering element. The tunneling-barrier may include a semiconductor or an insulator. Thus, the diode may be a carbon/semiconductor/carbon diode. The semiconductor in the diode may be intrinsic or doped. The semiconductor may be depleted when the diode is under equilibrium conditions. For example, the semiconductor may be lightly doped such that the depletion region extends from one end of the semiconductor region to the other end. The diode may be a carbon/insulator/carbon diode.
    Type: Application
    Filed: December 16, 2009
    Publication date: June 16, 2011
    Inventors: Abhijit Bandyopadhyay, Franz Kreupl, Andrei Mihnea, Li Xiao
  • Patent number: 7952936
    Abstract: Methods and devices are disclosed, some such methods comprising applying a verify pass-through voltage to unselected select lines of the floating-gate memory array that is greater than a read pass-through voltage applied to the unselected select lines. Other methods involve utilizing a cell current for reading a value from one or more memory cells in program-verify operations that is lower than a cell current for reading the value from the one or more memory cells in read operations.
    Type: Grant
    Filed: October 27, 2009
    Date of Patent: May 31, 2011
    Assignee: Micron Technology, Inc.
    Inventors: Andrei Mihnea, Todd Marquart, Jeffrey Kessenich
  • Publication number: 20110089391
    Abstract: A storage system and method for forming a storage system that uses punch-through diodes as a steering element in series with a reversible resistivity-switching element is described. The punch-through diode allows bipolar operation of a cross-point memory array. The punch-through diode may have a symmetrical non-linear current/voltage relationship. The punch-through diode has a high current at high bias for selected cells and a low leakage current at low bias for unselected cells. Therefore, it is compatible with bipolar switching in cross-point memory arrays having resistive switching elements. The punch-through diode may be a N+/P?/N+ device or a P+/N?/P+ device.
    Type: Application
    Filed: October 20, 2009
    Publication date: April 21, 2011
    Inventors: Andrei Mihnea, Deepak C. Sekar, George Samachisa, Roy Scheuerlein, Li Xiao
  • Patent number: 7924623
    Abstract: Embodiments of the present disclosure provide methods, devices, modules, and systems for operating memory cells. One method includes: performing an erase operation on a selected group of memory cells, the selected group including a number of reference cells and a number of data cells; performing a programming monitor operation on the number of reference cells as part of the erase operation; and determining a number of particular operating parameters associated with operating the number of data cells at least partially based on the programming monitor operation performed on the number of reference cells.
    Type: Grant
    Filed: May 27, 2008
    Date of Patent: April 12, 2011
    Assignee: Micron Technology, Inc.
    Inventors: Akira Goda, Andrei Mihnea
  • Publication number: 20110032768
    Abstract: Methods for erasing a memory device and memory systems are provided, such as those including a non-volatile memory device is erased by using an intermediate erase step prior to a normal erase step. The intermediate erase step is comprised of an erase pulse voltage, applied to the semiconductor well of the selected memory block of memory cells, while edge rows of memory cells are biased at a low positive voltage (e.g., 0.2-2V). An erase verify operation is then performed. If the selected memory block is not erased, a normal memory erase step is then performed in which the same erase pulse voltage is used but all of the rows are biased at ground potential as in a normal erase step. If the memory block is still fails the erase verify operation, the erase pulse voltage is increased and the process repeated.
    Type: Application
    Filed: October 18, 2010
    Publication date: February 10, 2011
    Inventors: Andrei Mihnea, William Kueber
  • Patent number: 7885091
    Abstract: A memory system includes a substrate, control circuitry on the substrate, a three dimensional memory array (above the substrate) that includes a plurality of memory cells with reversible resistance-switching elements, and a circuit for detecting the setting and resetting of the reversible resistance-switching elements. In one aspect a circuit that has one or more clock inputs is run for a predetermined number of clock cycles. The circuit generates an amount of charge over the predetermined number of clock cycles. At most the amount of charge is provided to non-volatile storage element to program the non-volatile storage element. It is determined whether the non-volatile storage element is programmed to a desired state as a result of providing at most the amount of charge to the non-volatile storage element. Techniques disclosed herein can be applied to program memory cells other than memory cells with reversible resistance-switching elements.
    Type: Grant
    Filed: May 26, 2009
    Date of Patent: February 8, 2011
    Assignee: SanDisk 3D LLC
    Inventors: Andrei Mihnea, Luca Fasoli