Patents by Inventor Yashushi Ishii

Yashushi Ishii 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).

  • Three-dimensional memory device containing word lines having vertical protrusion regions and methods of making the same
    Patent number: 10211215
    Abstract: An alternating stack of insulating layers and spacer material layers is formed over a substrate. Each of the first insulating layers and the first sacrificial material layers includes a respective horizontally-extending portion and a respective non-horizontally-extending portion. Memory stack structures are formed through the horizontally-extending portions of the alternating stack. Regions of the non-horizontally-extending portions of the sacrificial material layers are masked with patterned etch mask portions. Unmasked first regions of the non-horizontally-extending portions of the first sacrificial material layers are selectively recessed, and the sacrificial material layers with electrically conductive layers. Each electrically conductive layer can include a vertical plate region and a protrusion region that protrudes above the vertical plate region and having a narrower lateral dimension that the vertical plate region.
    Type: Grant
    Filed: February 13, 2018
    Date of Patent: February 19, 2019
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Yashushi Ishii, Kazuto Watanabe, Michiaki Sano, Haruki Urata, Akira Takahashi, Tae-Kyung Kim