Abstract: A three dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate; memory stack structures vertically extending through the alternating stack; and a backside trench fill structure. The backside trench fill structure includes a backside trench insulating spacer and a backside contact via structure. The backside contact via structure may include a tapered metallic nitride liner and at least one core fill conductive material portion. Alternatively, the backside contact via structure may include a tungsten nitride liner, a metallic nitride liner other than tungsten nitride, and at least one core fill conductive material portion.

Abstract: A three dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate; memory stack structures vertically extending through the alternating stack; and a backside trench fill structure. The backside trench fill structure includes a backside trench insulating spacer and a backside contact via structure. The backside contact via structure may include a tapered metallic nitride liner and at least one core fill conductive material portion. Alternatively, the backside contact via structure may include a tungsten nitride liner, a metallic nitride liner other than tungsten nitride, and at least one core fill conductive material portion.