Patents by Inventor Karthik Sarpatwari

Karthik Sarpatwari 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: 20220284957
    Abstract: Systems, methods, and apparatus related to memory devices. In one approach, a memory device has a memory array including memory cells. A controller of the memory device applies multiple pre-read voltages to memory cells prior to performing write operations on the memory cells. The controller applies a first pre-read voltage to determine which of the memory cells have a sensed current that exceeds a threshold. In response to determining that a percentage of the memory cells exceeding the threshold is too low (e.g., below a fixed limit), the controller determines to apply a second pre-read voltage to the memory cells. The second pre-read voltage has a greater magnitude than the first pre-read voltage, and can be applied to ensure greater reliability in properly determining the existing programming state of the memory cells. The controller then applies write voltages to the memory cells as appropriate based on target logic states for each memory cell and the programming mode to be used by the controller.
    Type: Application
    Filed: May 25, 2022
    Publication date: September 8, 2022
    Inventors: Yen Chun Lee, Nevil N. Gajera, Karthik Sarpatwari
  • Publication number: 20220278103
    Abstract: Some embodiments include apparatuses and methods using a substrate, a pillar having a length perpendicular to the substrate, a first conductive plate, a second conductive plate, a memory cell located between the first and second conductive plates and electrically separated from the first and second conductive plates, and a conductive connection. The first conductive plate is located in a first level of the apparatus and being separated from the pillar by a first dielectric located in the first level. The second conductive plate is located in a second level of the apparatus and being separated from the pillar by a second dielectric located in the second level. The memory cell includes a first semiconductor material located in a third level of the apparatus between the first and second levels and contacting the pillar and the conductive connection, and a second semiconductor material located in a fourth level of the apparatus between the first and second levels and contacting the pillar.
    Type: Application
    Filed: May 16, 2022
    Publication date: September 1, 2022
    Inventors: Kamal M. Karda, Karthik Sarpatwari, Haitao Liu, Durai Vishak Nirmal Ramaswamy
  • Publication number: 20220278112
    Abstract: Some embodiments include apparatuses in which one of such apparatus includes a first memory cell including a first transistor having a first channel region coupled between a data line and a conductive region, and a first charge storage structure located between the first data line and the conductive region, and a second transistor having a second channel region coupled to and located between the first data line and the first charge storage structure; a second memory cell including a third transistor having a third channel region coupled between a second data line and the conductive region, and a second charge storage structure located between the second data line and the conductive region, and a fourth transistor having a fourth channel region coupled to and located between the second data line and the second charge storage structure; a conductive line forming a gate of each of the first, second, third, and fourth transistors; and a conductive structure located between the first and second charge storage stru
    Type: Application
    Filed: February 26, 2021
    Publication date: September 1, 2022
    Inventors: Kamal M. Karda, Haitao Liu, Karthik Sarpatwari, Durai Vishak Nirmal Ramaswamy, Alessandro Calderoni, Richard E. Fackenthal, Duane R. Mills
  • Patent number: 11417381
    Abstract: Some embodiments include apparatuses and methods operating the apparatuses. One of the apparatuses includes a first data line located over a substrate, a second data line located over the first data line, a third data line located over the second data line and electrically separated from the first and second data lines, and a memory cell coupled to the first, second, and third data lines. The memory cell includes a first material between the first and second data lines and electrically coupled to the first and second data lines; a second material located over the first data line and the first material, the second material electrically separated from the first material and electrically coupled to the third data line; and a memory element electrically coupled to the second material and electrically separated from the first material and first and second data lines.
    Type: Grant
    Filed: December 23, 2019
    Date of Patent: August 16, 2022
    Assignee: Micron Technology, Inc.
    Inventors: Karthik Sarpatwari, Kamal M. Karda, Durai Vishak Nirmal Ramaswamy
  • Publication number: 20220246202
    Abstract: The present disclosure includes apparatuses, methods, and systems for performing refresh operations on memory cells. A memory can include a group of memory cells and one or more additional memory cells whose data state is indicative of whether to refresh the group of memory cells. Circuitry is configured to apply a first voltage pulse to the group of memory cells to sense a data state of the memory cells of the group, apply, while the first voltage pulse is applied to the group of memory cells, a second voltage pulse having a greater magnitude than the first voltage pulse to the one or more additional memory cells to sense a data state of the one or more additional memory cells, and determine whether to perform a refresh operation on the group of memory cells based on the sensed data state of the one or more additional memory cells.
    Type: Application
    Filed: February 4, 2021
    Publication date: August 4, 2022
    Inventors: Karthik Sarpatwari, Lingming Yang, Nevil N. Gajera, John Christopher M. Sancon
  • Publication number: 20220246221
    Abstract: Systems, methods, and apparatus related to memory devices. In one approach, a memory device has a memory array including memory cells. A controller of the memory device evaluates background leakage in order to select a write voltage to apply to a memory cell when performing a programming operation. The write voltage is dynamically selected from two or more write voltages. These write voltages include a first write voltage that is a normal or default voltage, and a second write voltage that is a boosted write voltage. The controller applies a pre-sensing voltage and pre-read voltage to the memory cell, and determines first and second respective currents that result from applying these voltages. In response to determining that the first current exceeds a first threshold (indicating background leakage), and the second current is below a second threshold that is greater than the first threshold (indicating that the memory cell does not snap), the controller selects the second (boosted) write voltage.
    Type: Application
    Filed: February 4, 2021
    Publication date: August 4, 2022
    Inventors: Nevil N. Gajera, Karthik Sarpatwari, Zhongyuan Lu
  • Patent number: 11404130
    Abstract: Systems, methods, and apparatus related to memory devices. In one approach, a memory device has a memory array including memory cells. A controller of the memory device evaluates background leakage in order to select a write voltage to apply to a memory cell when performing a programming operation. The write voltage is dynamically selected from two or more write voltages. These write voltages include a first write voltage that is a normal or default voltage, and a second write voltage that is a boosted write voltage. The controller applies a pre-sensing voltage and pre-read voltage to the memory cell, and determines first and second respective currents that result from applying these voltages. In response to determining that the first current exceeds a first threshold (indicating background leakage), and the second current is below a second threshold that is greater than the first threshold (indicating that the memory cell does not snap), the controller selects the second (boosted) write voltage.
    Type: Grant
    Filed: February 4, 2021
    Date of Patent: August 2, 2022
    Assignee: Micron Technology, Inc.
    Inventors: Nevil N. Gajera, Karthik Sarpatwari, Zhongyuan Lu
  • Publication number: 20220223203
    Abstract: The present disclosure includes apparatuses, methods, and systems for increase of a sense current in memory. An embodiment includes a memory having a plurality of memory cells, and circuitry configured to apply, prior to sensing a data state of a memory cell of the plurality of memory cells, a voltage to an access line to which the memory cell is coupled, determine whether an amount of current on the access line in response to the applied voltage meets or exceeds a threshold amount of current, and determine whether to increase a magnitude of a current used to sense the data state of the memory cell based on whether the amount of current on the access line in response to the applied voltage meets or exceeds the threshold amount of current.
    Type: Application
    Filed: April 1, 2022
    Publication date: July 14, 2022
    Inventors: Zhongyuan Lu, Robert J. Gleixner, Karthik Sarpatwari
  • Publication number: 20220223605
    Abstract: Some embodiments include apparatuses and methods of forming the apparatuses. One of the apparatuses includes a memory cell and first, second, and third data lines located over a substrate. The memory cell includes a first transistor and a second transistor. The first transistor includes a charge storage structure located on a first level of the apparatus, and a first channel region electrically separated from the charge storage structure. The second transistor includes a second channel region located on a second level of the apparatus and electrically coupled to the charge storage structure. The first and second data lines are located on a third level of the apparatus and electrically coupled to the first channel region. The first level is between the substrate and the third level. The third data line is electrically coupled to the second channel region and electrically separated from the first channel region.
    Type: Application
    Filed: April 4, 2022
    Publication date: July 14, 2022
    Inventors: Kamal M. Karda, Karthik Sarpatwari, Durai Vishak Nirmal Ramaswamy, Haitao Liu
  • Publication number: 20220223212
    Abstract: The present disclosure includes apparatuses, methods, and systems for multi-state programming of memory cells. An embodiment includes a memory having a plurality of memory cells, and circuitry configured to program a memory cell of the plurality of memory cells to one of four possible data states by applying a first voltage pulse to the memory cell wherein the first voltage pulse has a first polarity and a first magnitude, and applying a second voltage pulse to the memory cell wherein the second voltage pulse has a second polarity and a second magnitude, and the second voltage pulse is applied for a shorter duration than the first voltage pulse.
    Type: Application
    Filed: March 30, 2022
    Publication date: July 14, 2022
    Inventors: Karthik Sarpatwari, Nevil N. Gajera
  • Publication number: 20220208256
    Abstract: Some embodiments include apparatuses and methods of forming the apparatuses. One of the apparatuses includes multiple levels of two-transistor (2T) memory cells vertically arranged above a substrate. Each 2T memory cell includes a charge storage transistor having a gate, a write transistor having a gate, a vertically extending access line, and a single bit line pair. The source or drain region of the write transistor is directly coupled to a charge storage structure of the charge storage transistor. The vertically extending access line is coupled to gates of both the charge storage transistor and the write transistor of 2T memory cells in multiple respective levels of the multiple vertically arranged levels. The vertically extending access line and the single bit line pair are used for both write operations and read operations of each of the 2T memory cells to which they are coupled.
    Type: Application
    Filed: December 8, 2021
    Publication date: June 30, 2022
    Inventors: Kamal M. Karda, Haitao Liu, Karthik Sarpatwari, Durai Vishak Nirmal Ramaswamy
  • Patent number: 11367483
    Abstract: Methods, systems, and devices for memory cell selection to enable a memory device to select a targeted memory cell during a write operation are described. The memory device may apply a first pulse to a selected bit line of the targeted memory cell while applying a voltage to deselected word lines to prevent current leakage. If the targeted memory is not selected after the first pulse, the memory device may apply a second pulse to the selected bit line while applying a voltage to the deselected word lines. If the targeted memory cell is not selected following the second pulse, the memory device may apply a third pulse to the selected bit line while applying the voltage to the deselected word lines. The memory device may detect a snapback event after any of the pulses if the targeted memory cell is selected.
    Type: Grant
    Filed: November 4, 2020
    Date of Patent: June 21, 2022
    Assignee: Micron Technology Inc.
    Inventors: Josephine T. Hamada, Mingdong Cui, Joseph M. McCrate, Karthik Sarpatwari, Jessica Chen
  • Patent number: 11367484
    Abstract: Systems, methods, and apparatus related to memory devices. In one approach, a memory device has a memory array including memory cells. A controller of the memory device applies multiple pre-read voltages to memory cells prior to performing write operations on the memory cells. The controller applies a first pre-read voltage to determine which of the memory cells have a sensed current that exceeds a threshold. In response to determining that a percentage of the memory cells exceeding the threshold is too low (e.g., below a fixed limit), the controller determines to apply a second pre-read voltage to the memory cells. The second pre-read voltage has a greater magnitude than the first pre-read voltage, and can be applied to ensure greater reliability in properly determining the existing programming state of the memory cells. The controller then applies write voltages to the memory cells as appropriate based on target logic states for each memory cell and the programming mode to be used by the controller.
    Type: Grant
    Filed: January 21, 2021
    Date of Patent: June 21, 2022
    Assignee: Micron Technology, Inc.
    Inventors: Yen Chun Lee, Nevil N. Gajera, Karthik Sarpatwari
  • Patent number: 11355554
    Abstract: An example apparatus includes a three-dimensional (3D) memory array including a sense line and a plurality of vertical stacks. Each respective on of the vertical stacks includes a different respective portion of the sense line, a first memory cell coupled to that portion of the sense line, a second memory cell coupled to that portion of the sense line, a first access line coupled to the first memory cell and a second access line coupled to the second memory cell. The first and second access lines are perpendicular to the sense line.
    Type: Grant
    Filed: May 8, 2020
    Date of Patent: June 7, 2022
    Assignee: Micron Technology, Inc.
    Inventors: Lingming Yang, Karthik Sarpatwari, Fabio Pellizzer, Nevil N. Gajera, Lei Wei
  • Patent number: 11355209
    Abstract: Methods, systems, and devices for accessing a multi-level memory cell are described. The memory device may perform a read operation that includes pre-read portion and a read portion to access the multi-level memory cell. During the pre-read portion, the memory device may apply a plurality of voltages to a plurality of memory cells to identify a likely distribution of memory cells storing a first logic state. During the read portion, the memory device may apply a first read voltage to a memory cell based on performing the pre-read portion. The memory device may apply a second read voltage to the memory cell during the read portion that is based on the first read voltage. The memory device may determine the logic state stored by the memory cell based on applying the first read voltage and the second read voltage.
    Type: Grant
    Filed: July 10, 2020
    Date of Patent: June 7, 2022
    Assignee: Micron Technology, Inc.
    Inventors: Karthik Sarpatwari, Xuan-Anh Tran, Jessica Chen, Jason A. Durand, Nevil N. Gajera, Yen Chun Lee
  • Patent number: 11335684
    Abstract: Some embodiments include apparatuses and methods using a substrate, a pillar having a length perpendicular to the substrate, a first conductive plate, a second conductive plate, a memory cell located between the first and second conductive plates and electrically separated from the first and second conductive plates, and a conductive connection. The first conductive plate is located in a first level of the apparatus and being separated from the pillar by a first dielectric located in the first level. The second conductive plate is located in a second level of the apparatus and being separated from the pillar by a second dielectric located in the second level. The memory cell includes a first semiconductor material located in a third level of the apparatus between the first and second levels and contacting the pillar and the conductive connection, and a second semiconductor material located in a fourth level of the apparatus between the first and second levels and contacting the pillar.
    Type: Grant
    Filed: August 26, 2020
    Date of Patent: May 17, 2022
    Assignee: Micron Technology, Inc.
    Inventors: Kamal M. Karda, Karthik Sarpatwari, Haitao Liu, Durai Vishak Nirmal Ramaswamy
  • Patent number: 11295811
    Abstract: The present disclosure includes apparatuses, methods, and systems for increase of a sense current in memory. An embodiment includes a memory having a plurality of memory cells, and circuitry configured to apply, prior to sensing a data state of a memory cell of the plurality of memory cells, a voltage to an access line to which the memory cell is coupled, determine whether an amount of current on the access line in response to the applied voltage meets or exceeds a threshold amount of current, and determine whether to increase a magnitude of a current used to sense the data state of the memory cell based on whether the amount of current on the access line in response to the applied voltage meets or exceeds the threshold amount of current.
    Type: Grant
    Filed: August 27, 2020
    Date of Patent: April 5, 2022
    Assignee: Micron Technology, Inc.
    Inventors: Zhongyuan Lu, Robert J. Gleixner, Karthik Sarpatwari
  • Patent number: 11296094
    Abstract: Some embodiments include apparatuses and methods of forming the apparatuses. One of the apparatuses includes a memory cell and first, second, and third data lines located over a substrate. The memory cell includes a first transistor and a second transistor. The first transistor includes a charge storage structure located on a first level of the apparatus, and a first channel region electrically separated from the charge storage structure. The second transistor includes a second channel region located on a second level of the apparatus and electrically coupled to the charge storage structure. The first and second data lines are located on a third level of the apparatus and electrically coupled to the first channel region. The first level is between the substrate and the third level. The third data line is electrically coupled to the second channel region and electrically separated from the first channel region.
    Type: Grant
    Filed: December 23, 2019
    Date of Patent: April 5, 2022
    Assignee: Micron Technology, Inc.
    Inventors: Kamal M. Karda, Karthik Sarpatwari, Durai Vishak Nirmal Ramaswamy, Haitao Liu
  • Patent number: 11295822
    Abstract: The present disclosure includes apparatuses, methods, and systems for multi-state programming of memory cells. An embodiment includes a memory having a plurality of memory cells, and circuitry configured to program a memory cell of the plurality of memory cells to one of four possible data states by applying a first voltage pulse to the memory cell wherein the first voltage pulse has a first polarity and a first magnitude, and applying a second voltage pulse to the memory cell wherein the second voltage pulse has a second polarity and a second magnitude, and the second voltage pulse is applied for a shorter duration than the first voltage pulse.
    Type: Grant
    Filed: August 14, 2020
    Date of Patent: April 5, 2022
    Assignee: Micron Technology, Inc.
    Inventors: Karthik Sarpatwari, Nevil N. Gajera
  • Publication number: 20220093190
    Abstract: Methods, systems, and devices for data-based polarity write operations are described. A write command may cause a set of data to be written to a set of memory cells. To write the set of data, a write operation that applies voltages across the memory cells based on a logic state of data to be written to the memory cells may be used. During a first interval of the write operation, a voltage may be applied across a memory cell based on a logic state of a data bit to be written to the memory cell. During a second interval of the write operation, a voltage may be applied across the memory cell based on an amount of charge conducted by the memory cell during the first interval.
    Type: Application
    Filed: September 28, 2021
    Publication date: March 24, 2022
    Inventors: Karthik Sarpatwari, Nevil N. Gajera, Hongmei Wang, Mingdong Cui