US 12,484,224 B2
Three-dimensional memory device including composite backside metal fill structures
Ryo Kambayashi, Yokkaichi (JP); and Kazuto Ohsawa, Yokkaichi (JP)
Assigned to Sandisk Technologies, Inc., Milpitas, CA (US)
Filed by SANDISK TECHNOLOGIES LLC, Addison, TX (US)
Filed on Feb. 19, 2024, as Appl. No. 18/581,037.
Application 18/581,037 is a continuation in part of application No. 17/806,406, filed on Jun. 10, 2022, granted, now 12,408,337.
Prior Publication US 2024/0196619 A1, Jun. 13, 2024
Int. Cl. H10B 43/27 (2023.01); H10B 41/27 (2023.01)
CPC H10B 43/27 (2023.02) [H10B 41/27 (2023.02)] 2 Claims
OG exemplary drawing
 
1. A three dimensional memory device, comprising:
an alternating stack of insulating layers and electrically conductive layers;
memory openings vertically extending through the alternating stack;
memory opening fill structures located in the memory openings and comprising a respective vertical semiconductor channel and a respective vertical stack of memory elements; and
a backside trench fill structure laterally extending along a first horizontal direction,
wherein:
the backside trench fill structure comprises a backside trench insulating spacer and a backside contact via structure that is laterally surrounded by the backside trench insulating spacer;
the backside contact via structure comprises:
a first metallic nitride liner comprising a nitride of titanium;
a first metal core fill conductive material portion consisting essentially of tungsten; and
a second metallic nitride liner comprising a nitride of the tungsten located between an inner sidewall of the first metallic nitride liner and an outer sidewall of the first metal core fill conductive material portion;
the second metallic nitride liner is polycrystalline; and
the backside contact via structure further comprises an amorphous tapered metallic nitride liner.