Patents by Inventor Daniele Vimercati

Daniele Vimercati 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: 20210312968
    Abstract: Methods, systems, and devices for low voltage ferroelectric memory cell sensing are described. As part of an access operation for a memory cell, gates of two cascodes may be biased to compensate for associated threshold voltages. An extracted signal corresponding to a charge stored in the memory cell may be transferred through a first cascode to charge a first capacitor. Similarly, a reference signal developed at a dummy digit line may be transferred through a second cascode to charge a second capacitor. By comparing the reference signal developed at the dummy digit line to the extracted signal from the memory cell, the effect of variations in memory cell performance on the sense window may be reduced. Additionally, based on biasing the gates of the cascodes, the difference between the signals compared at the sense component may be low compared to other sensing schemes.
    Type: Application
    Filed: April 21, 2021
    Publication date: October 7, 2021
    Inventor: Daniele Vimercati
  • Publication number: 20210304804
    Abstract: Methods, systems, and devices for memory array with multiplexed select lines are described. In some cases, a memory cell of the memory device may include a storage component, a first transistor coupled with a word line, and a second transistor coupled with a first select line to selectively couple the memory cell with a first digit line. A third transistor may be coupled with the first digit line and a sense component common to a set of digit lines and a set of select lines. A second select line may be coupled with the third transistor and configured to couple the sense component with the first digit line and to couple the sense component with a second digit line. The sense component may determine a logic state stored by the memory cell based on the signal from the first digit line and the signal from the second digit line.
    Type: Application
    Filed: March 26, 2020
    Publication date: September 30, 2021
    Inventor: Daniele Vimercati
  • Publication number: 20210304806
    Abstract: Methods, systems, and devices for temperature-based access timing for a memory device are described. In some memory devices, accessing memory cells may be associated with different operations that are variously dependent on a temperature of the memory device. For example, some operations associated with accessing a memory cell may have a longer duration and others a shorter duration depending on the temperature of the memory device. In accordance with examples as disclosed herein, a memory device may be configured for performing some portions of an access operation according to a duration that is proportional to a temperature of the memory device, and performing other portions of the access operation according to a duration that is inversely proportional to a temperature of the memory device.
    Type: Application
    Filed: March 22, 2021
    Publication date: September 30, 2021
    Inventors: Victor Wong, Sihong Kim, Hiroshi Akamatsu, Daniele Vimercati, John D. Porter
  • Patent number: 11133048
    Abstract: Methods, systems, and devices for a sensing scheme that extracts the full or nearly full remnant polarization charge difference between two logic states of a ferroelectric memory cell or cells is described. The scheme employs a charge mirror to extract the full charge difference between the two states of a selected memory cell. The charge mirror may transfer the memory cell polarization charge to an amplification capacitor. The signal on the amplification capacitor may then be compared with a reference voltage to detect the logic state of the memory cell.
    Type: Grant
    Filed: July 8, 2019
    Date of Patent: September 28, 2021
    Assignee: Micron Technology, Inc.
    Inventors: Xinwei Guo, Daniele Vimercati
  • Patent number: 11133047
    Abstract: Methods, systems, and devices for digit line management for a memory array are described. A memory array may include a plate that is common to a plurality of memory cells. Each memory cell associated with the common plate may be coupled with a respective digit line. One or more memory cells common to the plate may be accessed by concurrently selecting the plate and each digit line associated with the plate. Concurrent selection of all digit lines associated with the plate may be supported by shield lines between the selected digit lines. Additionally or alternatively, selection of all digit lines associated with the plate may be supported by improved sensing schemes and related amplifier configurations.
    Type: Grant
    Filed: June 24, 2019
    Date of Patent: September 28, 2021
    Assignee: Micron Technology, Inc.
    Inventors: Xinwei Guo, Daniele Vimercati
  • Patent number: 11120859
    Abstract: Methods, systems, and devices for operating a ferroelectric memory cell or cells are described. A ferroelectric memory cell may be selected using a selection component that is in electronic communication with a sense amplifier and a ferroelectric capacitor of a ferroelectric memory cell. A voltage applied to the ferroelectric capacitor may be sized to increase the signal sensed during a read operation. The ferroelectric capacitor may be isolated from the sense amplifier during the read operation. This isolation may avoid stressing the ferroelectric capacitor which may otherwise occur due to the applied read voltage and voltage introduce by the sense amplifier during the read operation.
    Type: Grant
    Filed: August 21, 2018
    Date of Patent: September 14, 2021
    Assignee: Micron Technology, Inc.
    Inventor: Daniele Vimercati
  • Publication number: 20210264960
    Abstract: Methods, systems, and devices related to wear leveling for random access and ferroelectric memory are described. Non-volatile memory devices, e.g., ferroelectric random access memory (FeRAM) may utilize wear leveling to extend life time of the memory devices by avoiding reliability issues due to a limited cycling capability. A wear-leveling pool, or number of cells used for a wear-leveling application, may be expanded by softening or avoiding restrictions on a source page and a destination page within a same section of memory array. In addition, error correction code may be applied when moving data from the source page to the destination page to avoid duplicating errors present in the source page.
    Type: Application
    Filed: March 9, 2021
    Publication date: August 26, 2021
    Inventors: Richard E. Fackenthal, Daniele Vimercati, Duane R. Mills
  • Patent number: 11087817
    Abstract: Methods, systems, and devices for offset cancellation for latching in memory devices are described. A memory device may include a sense component comprising a first and second transistor. In some cases, a memory device may further include a first capacitor coupled to the first transistor and a second capacitor coupled to the second transistor and a first switching component coupled between a voltage source and the first capacitor and the second capacitor. For example, the first switching component may be activated, a reference voltage may be applied to the sense component, and the first switching component may then be deactivated. In some examples, a voltage offset may be measured across both the first and the second capacitor.
    Type: Grant
    Filed: May 4, 2020
    Date of Patent: August 10, 2021
    Assignee: Micron Technology, Inc.
    Inventor: Daniele Vimercati
  • Patent number: 11087816
    Abstract: A ferroelectric capacitor of a memory cell may be in electronic communication with a sense capacitor through a digit line. The digit line may be virtually grounded during memory cell sensing, limiting or avoiding voltage drop across the digit line, and allowing all or substantially all of the stored charge of the ferroelectric capacitor to be extracted and transferred to the sense capacitor. Virtually grounding the digit line may be achieved by activating a switching component (e.g., a p-type field-effect transistor) that is electronic communication with the digit line. The charge of the ferroelectric capacitor may be transferred through the switching component. A sense amplifier may compare the voltage of the sense capacitor to a reference voltage in order to determine the stored logic state of the memory cell.
    Type: Grant
    Filed: November 27, 2018
    Date of Patent: August 10, 2021
    Assignee: Micron Technology, Inc.
    Inventor: Daniele Vimercati
  • Patent number: 11081157
    Abstract: Apparatuses and techniques for compensating for noise, such as a leakage current, in a memory array are described. Leakage currents may, for example, be introduced onto a digit line from unselected memory cells. In some cases, a compensation component may be coupled with the digit line during a first phase of a read operation, before the target memory cell has been coupled with the digit line. The compensation component may sample a current on the digit line and store a representation of the sampled current. During a second phase of the read operation, the target memory cell may be coupled with the digit line. During the second phase, the compensation component may compensate for leakage or other parasitic effects by outputting a current on the digit line during the read operation based on the stored representation of the sampled current.
    Type: Grant
    Filed: December 11, 2018
    Date of Patent: August 3, 2021
    Assignee: Micron Technology, Inc.
    Inventor: Daniele Vimercati
  • Publication number: 20210193211
    Abstract: The present disclosure includes apparatuses, methods, and systems for current separation for memory sensing. An embodiment includes applying a sensing voltage to a memory cell having a ferroelectric material, and determining a data state of the memory cell by separating a first current output by the memory cell while the sensing voltage is being applied to the memory cell and a second current output by the memory cell while the sensing voltage is being applied to the memory cell, wherein the first current output by the memory cell corresponds to a first polarization state of the ferroelectric material of the memory cell and the second current output by the memory cell corresponds a second polarization state of the ferroelectric material of the memory cell.
    Type: Application
    Filed: February 26, 2021
    Publication date: June 24, 2021
    Inventor: Daniele Vimercati
  • Patent number: 11043253
    Abstract: Methods, systems, and apparatuses for self-referencing memory cells are described. A reference value for a cell may be created through multiple sense operations on the cell. The cell may be sensed several times and an average of at least two sensing operations may be used as a reference for another sense operation. For example, the cell may be sensed and the resulting charge stored at a capacitor. The cell may be biased to one state, sensed a second time, and the resulting charge stored at another capacitor. The cell may be biased to another state, sensed a third time, and the resulting charge stored to another capacitor. The values from the second and third sensing operations may be averaged and used as a reference value in a comparison with value of the first sensing operation to determine a logic state of the cell.
    Type: Grant
    Filed: July 6, 2020
    Date of Patent: June 22, 2021
    Assignee: Micron Technology, Inc.
    Inventor: Daniele Vimercati
  • Patent number: 11043503
    Abstract: Methods, systems, and devices for plate node configurations and operations for a memory array are described. A single plate node of a memory array may be coupled to multiple rows or columns of memory cells (e.g., ferroelectric memory cells) in a deck of memory cells. The single plate node may perform the functions of multiple plate nodes. The number of contacts to couple the single plate node to the substrate may be less than the number of contacts to couple multiple plate nodes to the substrate. Connectors or sockets in a memory array with a single plate node may define a size that is less than a size of the connectors or sockets with multiple plate nodes. In some examples, a single plate node of the memory array may be coupled to multiple lines of a memory cells in multiple decks of memory cells.
    Type: Grant
    Filed: October 28, 2019
    Date of Patent: June 22, 2021
    Assignee: Micron Technology, Inc.
    Inventor: Daniele Vimercati
  • Publication number: 20210166736
    Abstract: Methods, systems, and devices for differential amplifier schemes for sensing memory cells are described. In one example, an apparatus may include a memory cell, a differential amplifier having a first input node, a second input node, and an output node that is coupled with the first input node via a first capacitor, and a second capacitor coupled with the first input node. The apparatus may include a controller configured to cause the apparatus to bias the first capacitor, couple the memory cell with the first input node, and generate, at the output node, a sense signal based at least in part on biasing the first capacitor and coupling the memory cell with the first input node. The apparatus may also include a sense component configured to determine a logic state stored by the memory cell based at least in part on the sense signal.
    Type: Application
    Filed: December 3, 2019
    Publication date: June 3, 2021
    Inventors: Daniele Vimercati, Xinwei Guo
  • Patent number: 11004493
    Abstract: Methods, systems, and devices for differential amplifier schemes for non-switching state compensation are described. During a read operation, a first node of a memory cell may be coupled with an input of differential amplifier while a second node of the memory cell may be biased with a first voltage (e.g., to apply a first read voltage across the memory cell). The second node of the memory cell may subsequently be biased with a second voltage (e.g., to apply a second read voltage across the memory cell), which may support the differential amplifier operating in a manner that compensates for a non-switching state of the memory cell. By compensating for a non-switching state of a memory cell during read operations, read margins may be increased.
    Type: Grant
    Filed: December 5, 2019
    Date of Patent: May 11, 2021
    Assignee: Micron Technology, Inc.
    Inventors: Daniele Vimercati, Xinwei Guo
  • Patent number: 10998029
    Abstract: Methods, systems, and devices for low voltage ferroelectric memory cell sensing are described. As part of an access operation for a memory cell, gates of two cascodes may be biased to compensate for associated threshold voltages. An extracted signal corresponding to a charge stored in the memory cell may be transferred through a first cascode to charge a first capacitor. Similarly, a reference signal developed at a dummy digit line may be transferred through a second cascode to charge a second capacitor. By comparing the reference signal developed at the dummy digit line to the extracted signal from the memory cell, the effect of variations in memory cell performance on the sense window may be reduced. Additionally, based on biasing the gates of the cascodes, the difference between the signals compared at the sense component may be low compared to other sensing schemes.
    Type: Grant
    Filed: January 17, 2020
    Date of Patent: May 4, 2021
    Assignee: Micron Technology, Inc.
    Inventor: Daniele Vimercati
  • Publication number: 20210110863
    Abstract: Methods and apparatus for sensing a memory cell using lower offset, higher speed sense amplifiers are described. A sense amplifier may include an amplifier component that is configurable to operate in an amplifier mode or a latch mode. In some examples, the amplifier component may be configured to operate in the amplifier or latch mode by activating or deactivating switching components inside the amplifier component. When configured to operate in the amplifier mode, the amplifier component may be used, during a read operation of a memory cell, to pre-charge a digit line and/or amplify a signal received from the memory cell. When configured to operate in the latch mode, the amplifier component may be used to latch a state of the memory cell. In some cases, the amplifier component may use some of the same internal circuitry for pre-charging the digit line, amplifying the signal, and/or latching the state.
    Type: Application
    Filed: October 23, 2020
    Publication date: April 15, 2021
    Inventors: Xinwei Guo, Daniele Vimercati
  • Patent number: 10978126
    Abstract: Methods, systems, and devices for operating a ferroelectric memory cell or cells are described. A ground reference scheme may be employed in a digit line voltage sensing operation. A positive voltage may be applied to a memory cell; and after a voltage of the digit line of the cell has reached a threshold, a negative voltage may be applied to cause the digit line voltages to center around ground before a read operation. In another example, a first voltage may be applied to a memory cell and then a second voltage that is equal to an inverse of the first voltage may be applied to a reference capacitor that is in electronic communication with a digit line of the memory cell to cause the digit line voltages to center around ground before a read operation.
    Type: Grant
    Filed: November 8, 2018
    Date of Patent: April 13, 2021
    Inventors: Daniele Vimercati, Scott James Derner, Umberto Di Vincenzo, Christopher Johnson Kawamura, Eric S. Carman
  • Patent number: 10978130
    Abstract: Methods, systems, and devices for temperature-based access timing for a memory device are described. In some memory devices, accessing memory cells may be associated with different operations that are variously dependent on a temperature of the memory device. For example, some operations associated with accessing a memory cell may have a longer duration and others a shorter duration depending on the temperature of the memory device. In accordance with examples as disclosed herein, a memory device may be configured for performing some portions of an access operation according to a duration that is proportional to a temperature of the memory device, and performing other portions of the access operation according to a duration that is inversely proportional to a temperature of the memory device.
    Type: Grant
    Filed: March 25, 2020
    Date of Patent: April 13, 2021
    Assignee: Micron Technology, Inc.
    Inventors: Victor Wong, Sihong Kim, Hiroshi Akamatsu, Daniele Vimercati, John D. Porter
  • Patent number: 10971203
    Abstract: Methods, systems, and devices related to wear leveling for random access and ferroelectric memory are described. Non-volatile memory devices, e.g., ferroelectric random access memory (FeRAM) may utilize wear leveling to extend life time of the memory devices by avoiding reliability issues due to a limited cycling capability. A wear-leveling pool, or number of cells used for a wear-leveling application, may be expanded by softening or avoiding restrictions on a source page and a destination page within a same section of memory array. In addition, error correction code may be applied when moving data from the source page to the destination page to avoid duplicating errors present in the source page.
    Type: Grant
    Filed: July 8, 2019
    Date of Patent: April 6, 2021
    Assignee: Micron Technology, Inc.
    Inventors: Richard E. Fackenthal, Daniele Vimercati, Duane R. Mills