Patents by Inventor James W. Reiner

James W. Reiner 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: 11894037
    Abstract: In a memory array with a cross-point structure, at each cross-point junction a programmable resistive memory element, such as an MRAM memory cell, is connected in series with a threshold switching selector, such as an ovonic threshold switch. The threshold switching selector switches to a conducting state when a voltage above a threshold voltage is applied. When powered down for extended periods, the threshold voltage can drift upward. If the drift is excessive, this can make the memory cell difficult to access and can disturb stored data values when accessed. Techniques are presented to determine whether excessive voltage threshold drift may have occurred, including a read based test and a time based test. Techniques are also presented for initializing a cross-point array, for both first fire and cold start, by using voltage levels shifted from half-select voltage levels used in a standard memory access.
    Type: Grant
    Filed: April 12, 2022
    Date of Patent: February 6, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Michael Grobis, James W. Reiner, Michael Nicolas Albert Tran, Juan P. Saenz, Gerrit Jan Hemink
  • Publication number: 20230326506
    Abstract: In a memory array with a cross-point structure, at each cross-point junction a programmable resistive memory element, such as an MRAM memory cell, is connected in series with a threshold switching selector, such as an ovonic threshold switch. The threshold switching selector switches to a conducting state when a voltage above a threshold voltage is applied. When powered down for extended periods, the threshold voltage can drift upward. If the drift is excessive, this can make the memory cell difficult to access and can disturb stored data values when accessed. Techniques are presented to determine whether excessive voltage threshold drift may have occurred, including a read based test and a time based test. Techniques are also presented for initializing a cross-point array, for both first fire and cold start, by using voltage levels shifted from half-select voltage levels used in a standard memory access.
    Type: Application
    Filed: April 12, 2022
    Publication date: October 12, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Michael Grobis, James W. Reiner, Michael Nicolas Albert Tran, Juan P. Saenz, Gerrit Jan Hemink
  • Publication number: 20230267981
    Abstract: Technology is disclosed for improving read margin in a cross-point memory array. Drive transistors pass a read and write currents to the cross-point memory array. The read current charges a selected word line to turn on a threshold switching selector of a selected memory cell. While the threshold switching selector is on, the current (read or write) passes through the selected memory cell. The memory system applies a smaller overdrive voltage to the drive transistor when the drive transistor is passing the read current than when the drive transistor is passing the write current. A smaller overdrive voltage increases the resistance of the drive transistor which improves read margin. Increasing the resistance of the drive transistor increases the resistance seen by the threshold switching selector in the selected memory cell, which reduces the Ihold of the threshold switching selector. Reducing Ihold of the threshold switching selector improves read margin.
    Type: Application
    Filed: February 22, 2022
    Publication date: August 24, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Ward Parkinson, James O'Toole, Thomas Trent, Nathan Franklin, Michael Grobis, James W. Reiner, Hans Jurgen Richter, Michael Nicolas Albert Tran
  • Patent number: 9595280
    Abstract: A procedure for accurately determining thermal flying height control (TFC) touchdown power associated with a head-disk interface (HDI) in a hard disk drive (HDD) involves dithering the spacing corresponding to the HDI by applying an oscillating signal. The touchdown power with the HDI dithering applied is determined and, based on that and the dithering amplitude, the touchdown power without dithering applied, as well as the back-off power, is determinable.
    Type: Grant
    Filed: February 26, 2015
    Date of Patent: March 14, 2017
    Assignee: Western Digital Technologies, Inc
    Inventors: Sripathi V Canchi, Sukumar Rajauria, James W Reiner, Erhard Schreck
  • Patent number: 9536975
    Abstract: Ferroelectric semiconductor devices are provided by including a ferroelectric layer in the device that is made of a material that is not ferroelectric in bulk. Such layers can be disposed at interfaces to promote ferroelectric switching in a semiconductor device. Switching of conduction in the semiconductor is effected by the polarization of a mechanically bi-stable material. This material is not ferroelectric in bulk but can be considered to be when the thickness is sufficiently reduced down to a few atomic layers. Devices including such ferroelectric layers are suitable for various applications, such as transistors and memory cells (both volatile and non-volatile).
    Type: Grant
    Filed: June 21, 2015
    Date of Patent: January 3, 2017
    Assignee: Yale University
    Inventors: Alexie M. Kolpak, Fred J. Walker, James W. Reiner, Charles H. Ahn, Sohrab Ismail-Beigi
  • Publication number: 20160254016
    Abstract: A procedure for accurately determining thermal flying height control (TFC) touchdown power associated with a head-disk interface (HDI) in a hard disk drive (HDD) involves dithering the spacing corresponding to the HDI by applying an oscillating signal. The touchdown power with the HDI dithering applied is determined and, based on that and the dithering amplitude, the touchdown power without dithering applied, as well as the back-off power, is determinable.
    Type: Application
    Filed: February 26, 2015
    Publication date: September 1, 2016
    Inventors: Sripathi V. Canchi, Sukumar Rajauria, James W. Reiner, Erhard Schreck
  • Publication number: 20150311309
    Abstract: Ferroelectric semiconductor devices are provided by including a ferroelectric layer in the device that is made of a material that is not ferroelectric in bulk. Such layers can be disposed at interfaces to promote ferroelectric switching in a semiconductor device. Switching of conduction in the semiconductor is effected by the polarization of a mechanically bi-stable material. This material is not ferroelectric in bulk but can be considered to be when the thickness is sufficiently reduced down to a few atomic layers. Devices including such ferroelectric layers are suitable for various applications, such as transistors and memory cells (both volatile and non-volatile).
    Type: Application
    Filed: June 21, 2015
    Publication date: October 29, 2015
    Inventors: Alexie M. Kolpak, Fred J. Walker, James W. Reiner, Charles H. Ahn, Sohrab Ismail-Beigi
  • Publication number: 20130001809
    Abstract: Ferroelectric semiconductor devices are provided by including a ferroelectric layer in the device that is made of a material that is not ferroelectric in bulk. Such layers can be disposed at interfaces to promote ferroelectric switching in a semiconductor device. Switching of conduction in the semiconductor is effected by the polarization of a mechanically bi-stable material. This material is not ferroelectric in bulk but can be considered to be when the thickness is sufficiently reduced down to a few atomic layers. Devices including such ferroelectric layers are suitable for various applications, such as transistors and memory cells (both volatile and non-volatile).
    Type: Application
    Filed: September 29, 2010
    Publication date: January 3, 2013
    Inventors: Alexie M. Kolpak, Fred J. Walker, James W. Reiner, Charles H. Ahn, Sohrab Ismail-Beigi