Three-dimensional memory devices having through array contacts and methods for forming the same

Abstract

Embodiments of three-dimensional (3D) memory devices having through array contacts (TACs) and methods for forming the same are disclosed. In an example, a 3D memory device includes a substrate, a memory stack on the substrate comprising a plurality of conductor/dielectric layer pairs, a channel structure extending vertically through the conductor/dielectric layer pairs in the memory stack, a TAC extending vertically through the conductor/dielectric layer pairs in the memory stack, and a dummy channel structure filled with a dielectric layer and extending vertically through the conductor/dielectric layer pairs in the memory stack.