Patents by Inventor Pradhyumna Ravikirthi

Pradhyumna Ravikirthi 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).

  • Multi-tier memory stack structure containing non-overlapping support pillar structures and method of making thereof
    Patent number: 9881929
    Abstract: A first tier structure including a first alternating stack of first insulating layers and first sacrificial material layers is formed over a substrate. First support openings and first memory openings, filled with first support pillar structures and sacrificial pillar structures, respectively, are formed through the first tier structure. A second tier structure including a second alternating stack of second insulating layers and second sacrificial material layers is formed thereabove. Second support openings and second memory openings are formed through the second tier structure such that the second support openings do not overlap with the first support pillar structures and the second memory openings overlie the sacrificial pillar structures. Inter-tier memory openings are formed by removal of the sacrificial pillar structures. Memory stack structures and second support pillar structures are formed in the inter-tier memory openings and the second support openings, respectively.
    Type: Grant
    Filed: October 27, 2016
    Date of Patent: January 30, 2018
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Pradhyumna Ravikirthi, Jayavel Pachamuthu, Jagdish Sabde, Peter Rabkin