US 9,812,461 B2
Honeycomb cell structure three-dimensional non-volatile memory device
Yasushi Doda, Yokkaichi (JP); and Ryoichi Honma, Yokkaichi (JP)
Assigned to SANDISK TECHNOLOGIES LLC, Plano, TX (US)
Filed by SANDISK TECHNOLOGIES INC., Plano, TX (US)
Filed on Mar. 17, 2015, as Appl. No. 14/660,023.
Prior Publication US 2016/0276360 A1, Sep. 22, 2016
Int. Cl. H01L 29/792 (2006.01); H01L 27/11582 (2017.01); H01L 27/11565 (2017.01); H01L 29/51 (2006.01); H01L 27/1157 (2017.01)
CPC H01L 27/11582 (2013.01) [H01L 27/1157 (2013.01); H01L 27/11565 (2013.01); H01L 29/513 (2013.01)] 34 Claims
OG exemplary drawing
 
1. A monolithic three-dimensional memory device, comprising:
a stack of an alternating plurality of insulator layers and electrically conductive layers located over a substrate;
a plurality of memory stack structures located at vertices of hexagons of a hexagonal lattice and over the substrate; and
a plurality of dummy memory stack structures located at each center of a first subset of the hexagons,
wherein:
each of the memory stack structure and the dummy memory stack structures comprises a memory film and a vertical semiconductor channel;
the electrically conductive layers contact outer sidewalls of the plurality of memory stack structures;
outer sidewalls of the plurality of dummy memory stack structures are laterally spaced from the electrically conductive layers by a vertically spaced stack of dielectric material portions located at each level of the electrically conductive layers, wherein each dielectric material portion continuously extends through a region of the first subset of the hexagons and contacts an outermost sidewall of each dummy memory stack structure among the plurality of dummy memory stack structures and is laterally spaced from, and does not physically contact, any of the plurality of memory stack structures within the hexagonal lattice;
each hexagon of the hexagonal lattice has a pair of sides that are parallel to a first horizontal direction and perpendicular to a second horizontal direction;
the first subset of the hexagons constitutes a first one-dimensional array extending along the second horizontal direction; and
the monolithic three-dimensional memory device comprises at least one feature selected from:
a first feature that the monolithic three-dimensional memory device further comprises: source contact via structures located at each center of a second subset of hexagons that forms a second one-dimensional array that extends along the second horizontal direction, each source contact via structure being electrically shorted to a respective source region located over, or within, the substrate, and each source region contacting a horizontal semiconductor channel within the substrate, and further comprises well contact via structures located at each center of a third subset of hexagons that forms a third one-dimensional array that extends along the second horizontal direction, each well contact via structure being electrically shorted to a doped well having a doping of an opposite conductivity type than the source regions; and
a second feature that each dielectric material portion among the vertically spaced stack of dielectric material portions has an undulating width that is measured along the first horizontal direction and changes with a distance along the second horizontal direction.