Patents by Inventor Swaroop Kaza

Swaroop Kaza 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: 11923019
    Abstract: The present disclosure provides for improving data retention reliability. During a programming operation associated with a memory cell, after the memory cell passes verification of a first verification voltage level, a second verification voltage level can be applied to the memory cell. Based on a comparison of the voltage in the memory cell with the second verification voltage level, a bit line voltage may be applied. Based on the applied bit line voltage, fast bits associated with the memory cell can be upshifted to an upper portion of a final voltage distribution associated with the programming operation. Upshifting the fast bits counteracts the downshifting effect in a final voltage distribution that may be caused by charge leakage or electron loss.
    Type: Grant
    Filed: February 14, 2022
    Date of Patent: March 5, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Xiaojia Jia, Swaroop Kaza, Laidong Wang, Jiacen Guo
  • Patent number: 11862260
    Abstract: Read disturb audit techniques that include algorithmically applying audit verify voltages to erased wordlines in an open memory block are described. In an audit verify technique, a pass-through voltage ensured to be higher than any threshold voltage of any cell is applied to each wordline in an open memory block that includes one or more programmed memory cells, and an audit verify voltage lower than the pass-through voltage is applied to each erased wordline. A first bit count representing a number of non-conductive bitline(s) is determined and compared to a threshold value to determine whether to continue or discontinue block operation. In an audit verify and audit gap technique, the erased wordlines are divided into disjoint first and second groups, and an audit verify voltage and a non-verify voltage are alternatively applied to the groups in different audit verify stages.
    Type: Grant
    Filed: February 14, 2022
    Date of Patent: January 2, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Jiacen Guo, Swaroop Kaza
  • Publication number: 20230260583
    Abstract: The present disclosure provides for improving data retention reliability. During a programming operation associated with a memory cell, after the memory cell passes verification of a first verification voltage level, a second verification voltage level can be applied to the memory cell. Based on a comparison of the voltage in the memory cell with the second verification voltage level, a bit line voltage may be applied. Based on the applied bit line voltage, fast bits associated with the memory cell can be upshifted to an upper portion of a final voltage distribution associated with the programming operation. Upshifting the fast bits counteracts the downshifting effect in a final voltage distribution that may be caused by charge leakage or electron loss.
    Type: Application
    Filed: February 14, 2022
    Publication date: August 17, 2023
    Inventors: Xiaojia JIA, Swaroop KAZA, Laidong WANG, Jiacen GUO
  • Publication number: 20230260584
    Abstract: Read disturb audit techniques that include algorithmically applying audit verify voltages to erased wordlines in an open memory block are described. In an audit verify technique, a pass-through voltage ensured to be higher than any threshold voltage of any cell is applied to each wordline in an open memory block that includes one or more programmed memory cells, and an audit verify voltage lower than the pass-through voltage is applied to each erased wordline. A first bit count representing a number of non-conductive bitline(s) is determined and compared to a threshold value to determine whether to continue or discontinue block operation. In an audit verify and audit gap technique, the erased wordlines are divided into disjoint first and second groups, and an audit verify voltage and a non-verify voltage are alternatively applied to the groups in different audit verify stages.
    Type: Application
    Filed: February 14, 2022
    Publication date: August 17, 2023
    Inventors: JIACEN GUO, Swaroop Kaza
  • Publication number: 20230197174
    Abstract: A memory device with adaptive sense time tables is disclosed. In order to maintain a desired (initial or preset) threshold voltage distribution, the sense time is adjusted as the program-erase cycle count increases. The program-erase cycle process tends to wear down memory cells, causing the QPW window to expand and the threshold voltage to widen. However, by adjusting (i.e., reducing) the sense time for increased program-erase cycles, the QPW window and the threshold voltage can be at least substantially maintained. Additionally, systems and methods for adjusting sense time based on die-to-die variations are also disclosed.
    Type: Application
    Filed: December 20, 2021
    Publication date: June 22, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Jiacen GUO, Xiang YANG, Swaroop KAZA, Laidong WANG
  • Patent number: 11475958
    Abstract: A method of operating a memory system includes a first programming loop, which includes applying a first programming voltage to a control gate of a selected word line and applying a first bitline voltage to a bitline coupled to a first memory cell that is being programmed to a first data state and to a different bitline coupled to a second memory cell that is being programmed to a second data state. In a second programming loop, a second bitline voltage is applied to the bitline coupled to the first memory cell, and a third bitline voltage is applied to the bitline coupled to the second memory cell. The second bitline voltage is greater than the first bitline voltage to reduce a programming speed of the first bitline voltage to increase a programming speed of the second memory cell.
    Type: Grant
    Filed: March 4, 2021
    Date of Patent: October 18, 2022
    Assignee: SanDisk Technologies LLC
    Inventors: Yu-Chung Lien, Huai-yuan Tseng, Swaroop Kaza, Tomer Eliash
  • Publication number: 20220284965
    Abstract: A method of operating a memory system includes a first programming loop, which includes applying a first programming voltage to a control gate of a selected word line and applying a first bitline voltage to a bitline coupled to a first memory cell that is being programmed to a first data state and to a different bitline coupled to a second memory cell that is being programmed to a second data state. In a second programming loop, a second bitline voltage is applied to the bitline coupled to the first memory cell, and a third bitline voltage is applied to the bitline coupled to the second memory cell. The second bitline voltage is greater than the first bitline voltage to reduce a programming speed of the first bitline voltage to increase a programming speed of the second memory cell.
    Type: Application
    Filed: March 4, 2021
    Publication date: September 8, 2022
    Applicant: SanDisk Technologies LLC
    Inventors: Yu-Chung Lien, Huai-yuan Tseng, Swaroop Kaza, Tomer Eliash
  • Patent number: 10734084
    Abstract: A non-volatile storage system comprises non-volatile memory cells arranged in physical blocks, and one or more control circuits in communication with the non-volatile memory cells. The one or more control circuits are configured to write data to a physical block of the non-volatile memory cells with a scheme to reduce read disturb if a logical block associated with the physical block has a read intensity greater than a threshold.
    Type: Grant
    Filed: May 31, 2019
    Date of Patent: August 4, 2020
    Assignee: Western Digital Technologies, Inc.
    Inventors: Narayan Kuddannavar, Swaroop Kaza, Sainath Viswasarai
  • Patent number: 10643710
    Abstract: Apparatuses, systems, methods, and computer program products for enhanced erase retry of a non-volatile storage device are disclosed. An apparatus includes a non-volatile storage device and a controller. A controller includes a verification component configured to detect that an erase operation performed on an erase block of a non-volatile storage device is unsuccessful. A controller includes a parameter component configured to adjust one or more erase parameters for an erase operation. One or more erase parameters may be associated with one or more select gate drain storage cells of an erase block. A controller includes an erase component configured to retry an erase operation on an erase block with one or more adjusted erase parameters.
    Type: Grant
    Filed: November 30, 2017
    Date of Patent: May 5, 2020
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Divya Prasad, Sainath Viswasarai, Gopu S, Swaroop Kaza, Piyush Anil Dhotre, Chittoor Devarajan Sunilkumar
  • Publication number: 20190371416
    Abstract: A non-volatile storage system comprises non-volatile memory cells arranged in physical blocks, and one or more control circuits in communication with the non-volatile memory cells. The one or more control circuits are configured to write data to a physical block of the non-volatile memory cells with a scheme to reduce read disturb if a logical block associated with the physical block has a read intensity greater than a threshold.
    Type: Application
    Filed: May 31, 2019
    Publication date: December 5, 2019
    Applicant: Western Digital Technologies, Inc.
    Inventors: Narayan Kuddannavar, Swaroop Kaza, Sainath Viswasarai
  • Publication number: 20190164614
    Abstract: Apparatuses, systems, methods, and computer program products for enhanced erase retry of a non-volatile storage device are disclosed. An apparatus includes a non-volatile storage device and a controller. A controller includes a verification component configured to detect that an erase operation performed on an erase block of a non-volatile storage device is unsuccessful. A controller includes a parameter component configured to adjust one or more erase parameters for an erase operation. One or more erase parameters may be associated with one or more select gate drain storage cells of an erase block. A controller includes an erase component configured to retry an erase operation on an erase block with one or more adjusted erase parameters.
    Type: Application
    Filed: November 30, 2017
    Publication date: May 30, 2019
    Applicant: Western Digital Technologies, Inc.
    Inventors: DIVYA PRASAD, SAINATH VISWASARAI, GOPU S, SWAROOP KAZA, PIYUSH ANIL DHOTRE, CHITTOOR DEVARAJAN SUNILKUMAR
  • Patent number: 10235294
    Abstract: Apparatuses and techniques are described for performing a pre-read operation in preparation for a read operation in a memory device. The pre-read operation transitions the memory cells from a first read condition to a second read condition so that their threshold voltages will be in a desired, predictable range when the read occurs. The pre-read operation can involve maintaining voltages on a selected word line and unselected word lines at specified levels and for a specified duration which is relatively long compared to a duration of the read operation. The word line voltages, in combination with bit line and source line voltages, provide the channels of a NAND string in a conductive state and gradually transitions the memory cells to the second read condition.
    Type: Grant
    Filed: April 23, 2018
    Date of Patent: March 19, 2019
    Assignee: SanDisk Technologies LLC
    Inventors: Ching-Huang Lu, Swaroop Kaza, Piyush Sagdeo
  • Patent number: 9449690
    Abstract: A method of programming a memory system by selectively applying a program voltage to a selected wordline connected to a memory transistor to be programmed. A first bias voltage is applied to a first wordline adjacent to the source side of the selected wordline. The first bias voltage is also applied to a second wordline adjacent to the drain side of the selected wordline. A second bias voltage is applied to a third wordline adjacent to the drain side of the second wordline. A third bias voltage is applied to a fourth wordline adjacent to the source side of the first wordline. A pass voltage is also applied to the remaining wordlines that do not have one of a bias voltage and a program voltage applied, the pass voltage a selected voltage level.
    Type: Grant
    Filed: April 3, 2013
    Date of Patent: September 20, 2016
    Assignee: Cypress Semiconductor Corporation
    Inventors: Swaroop Kaza, Youseok Suh, Di Li, Sameer S. Haddad
  • Patent number: 9012299
    Abstract: In a method of fabricating a metal-insulator-metal (MIM) device, initially, a first electrode is provided. An oxide layer is provided on the first electrode, and a protective layer is provided on the oxide layer. An opening through the protective layer is provided to expose a portion of the oxide layer, and a portion of the first electrode underlying the exposed portion of the oxide layer is oxidized. A second electrode is provided in contact with the exposed portion of the oxide layer. In alternative embodiments, the initially provided oxide layer may be eliminated, and spacers of insulating material may be provided in the opening.
    Type: Grant
    Filed: August 14, 2014
    Date of Patent: April 21, 2015
    Assignee: Spansion LLC
    Inventors: Steven Avanzino, Tzu-Ning Fang, Swaroop Kaza, Dong-Xiang Liao, Wai Lo, Christie Marrian, Sameer Haddad
  • Publication number: 20140357044
    Abstract: In a method of fabricating a metal-insulator-metal (MIM) device, initially, a first electrode is provided. An oxide layer is provided on the first electrode, and a protective layer is provided on the oxide layer. An opening through the protective layer is provided to expose a portion of the oxide layer, and a portion of the first electrode underlying the exposed portion of the oxide layer is oxidized. A second electrode is provided in contact with the exposed portion of the oxide layer. in alternative embodiments, the initially provided oxide layer may be eliminated, and spacers of insulating material may be provided in the opening.
    Type: Application
    Filed: August 14, 2014
    Publication date: December 4, 2014
    Inventors: Steven AVANZINO, Tzu-Ning FANG, Swaroop KAZA, Dong-Xiang LIAO, Wai LO, Christie MARRIAN, Sameer HADDAD
  • Publication number: 20140301146
    Abstract: A method of programming a memory system by selectively applying a program voltage to a selected wordline connected to a memory transistor to be programmed. A first bias voltage is applied to a first wordline adjacent to the source side of the selected wordline. The first bias voltage is also applied to a second wordline adjacent to the drain side of the selected wordline. A second bias voltage is applied to a third wordline adjacent to the drain side of the second wordline. A third bias voltage is applied to a fourth wordline adjacent to the source side of the first wordline. A pass voltage is also applied to the remaining wordlines that do not have one of a bias voltage and a program voltage applied, the pass voltage a selected voltage level.
    Type: Application
    Filed: April 3, 2013
    Publication date: October 9, 2014
    Applicant: Spansion LLC
    Inventors: Swaroop KAZA, Youseok SUH, Di LI, Sameer HADDAD
  • Patent number: 8828837
    Abstract: In a method of fabricating a metal-insulator-metal (MIM) device, initially, a first electrode is provided. An oxide layer is provided on the first electrode, and a protective layer is provided on the oxide layer. An opening through the protective layer is provided to expose a portion of the oxide layer, and a portion of the first electrode underlying the exposed portion of the oxide layer is oxidized. A second electrode is provided in contact with the exposed portion of the oxide layer. In alternative embodiments, the initially provided oxide layer may be eliminated, and spacers of insulating material may be provided in the opening.
    Type: Grant
    Filed: April 19, 2013
    Date of Patent: September 9, 2014
    Assignee: Spansion LLC
    Inventors: Steven Avanzino, Tzu-Ning Fang, Swaroop Kaza, Dongxiang Liao, Wai Lo, Christie Marrian, Sameer Haddad
  • Publication number: 20130237030
    Abstract: In a method of fabricating a metal-insulator-metal (MIM) device, initially, a first electrode is provided. An oxide layer is provided on the first electrode, and a protective layer is provided on the oxide layer. An opening through the protective layer is provided to expose a portion of the oxide layer, and a portion of the first electrode underlying the exposed portion of the oxide layer is oxidized. A second electrode is provided in contact with the exposed portion of the oxide layer. In alternative embodiments, the initially provided oxide layer may be eliminated, and spacers of insulating material may be provided in the opening.
    Type: Application
    Filed: April 19, 2013
    Publication date: September 12, 2013
    Applicant: Spansion LLC
    Inventors: Steven AVANZINO, Tzu-Ning FANG, Swaroop KAZA, Dongxiang LIAO, Wai LO, Christie MARRIAN, Sameer HADDAD
  • Patent number: 8482959
    Abstract: A method of repairing a memory device is provided. If an erase process is unsuccessful, a repair process is performed. A programmed state of the memory device is determined, A subsequent erase process dependent on the programmed state is performed. Also, a method of programming and erasing a memory device is provided. The memory device includes first and second electrodes and a switching layer therebetween. A first on-state resistance characteristic of the memory device is provided in programming the memory device by application of a first voltage to the gate of a transistor in series with the memory device. Other on-state resistance characteristics of the memory device, different from the first on-state resistance characteristic, may be provided by application of other voltages, different from the first voltage, to the gate of the transistor.
    Type: Grant
    Filed: December 13, 2011
    Date of Patent: July 9, 2013
    Assignee: Spansion LLC
    Inventors: Swaroop Kaza, Sameer Haddad
  • Patent number: 8445913
    Abstract: In a method of fabricating a metal-insulator-metal (MIM) device, initially, a first electrode is provided. An oxide layer is provided on the first electrode, and a protective layer is provided on the oxide layer. An opening through the protective layer is provided to expose a portion of the oxide layer, and a portion of the first electrode underlying the exposed portion of the oxide layer is oxidized. A second electrode is provided in contact with the exposed portion of the oxide layer. In alternative embodiments, the initially provided oxide layer may be eliminated, and spacers of insulating material may be provided in the opening.
    Type: Grant
    Filed: October 30, 2007
    Date of Patent: May 21, 2013
    Assignee: Spansion LLC
    Inventors: Steven Avanzino, Tzu-Ning Fang, Swaroop Kaza, Dongxiang Liao, Wai Lo, Christie Marrian, Sameer Haddad