Patents by Inventor Akira Matsudaira

Akira Matsudaira 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: 9177808
    Abstract: An embodiment relates to a memory device that includes a semiconductor channel, a tunnel dielectric located over the semiconductor channel, a charge storage region located over the tunnel dielectric, a blocking dielectric located over the charge storage region, and a control gate located over the blocking dielectric. An interface between the blocking dielectric and the control gate substantially prevents oxygen diffusion from the blocking dielectric into the control gate.
    Type: Grant
    Filed: May 22, 2014
    Date of Patent: November 3, 2015
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Vinod R. Purayath, James Kai, Donovan Lee, Akira Matsudaira, Yuan Zhang
  • Publication number: 20150287733
    Abstract: Methods for preventing line collapse during the fabrication of NAND flash memory and other microelectronic devices that utilize closely spaced device structures with high aspect ratios are described. In some embodiments, one or more mechanical support structures may be used to provide lateral support between closely spaced device structures to prevent collapsing of the closely spaced device structures during an etching process (e.g., during a word line etch). In one example, during fabrication of a NAND flash memory, one or more mechanical support structures may be in place prior to performing a high aspect ratio word line etch or may be formed during the word line etch. In some cases, the one or more mechanical support structures may comprise portions of an inter-poly dielectric (IPD) layer that were in place prior to performing the word line etch.
    Type: Application
    Filed: April 7, 2014
    Publication date: October 8, 2015
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: Akira Matsudaira, Donovan Lee
  • Publication number: 20150255481
    Abstract: A fabrication process is provided for a 3D stacked non-volatile memory device which provides a source contact to memory holes at a bottom of a stack. The stack includes alternating control gate layers and dielectric layers on a substrate, and memory holes are etched through the stack. The process avoids the need to etch through films at the bottom of the memory hole. Instead, a path is formed from the bottom of the memory hole to the top of the stack. The path includes a horizontal portion using a voided trench in a substrate dielectric, and a passageway etched in the stack. The memory films, a channel material and a dielectric material are deposited throughout the interior surfaces of the void and the memory holes concurrently. The path is filled with metal to form a continuous, low resistance conductive path.
    Type: Application
    Filed: March 7, 2014
    Publication date: September 10, 2015
    Applicant: SanDisk Technologies Inc.
    Inventors: Matthias Baenninger, Johann Alsmeier, Akira Matsudaira, Jayavel Pachamuthu
  • Publication number: 20140346583
    Abstract: A non-volatile memory system, comprising non-volatile storage device with word lines having an inverted T-shape over floating gates. The inverted T-shape shape has a wider bottom portion and a thinner top portion. The thinner top portion increases the separation between adjacent word lines relative to the separation between the wider bottom portions. An air gap may separate adjacent word lines. The thinner top portion of the word lines increases the path length between adjacent word lines. The likelihood of word line to word line short may be decreased by reducing the electric field between adjacent word lines.
    Type: Application
    Filed: November 5, 2013
    Publication date: November 27, 2014
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: Vinod R. Purayath, James Kai, Donovan Lee, Yuan Zhang, Akira Matsudaira
  • Publication number: 20140346584
    Abstract: An embodiment relates to a memory device that includes a semiconductor channel, a tunnel dielectric located over the semiconductor channel, a charge storage region located over the tunnel dielectric, a blocking dielectric located over the charge storage region, and a control gate located over the blocking dielectric. An interface between the blocking dielectric and the control gate substantially prevents oxygen diffusion from the blocking dielectric into the control gate.
    Type: Application
    Filed: May 22, 2014
    Publication date: November 27, 2014
    Inventors: Vinod R. Purayath, James Kai, Donovan Lee, Akira Matsudaira, Yuan Zhang