THREE-DIMENSIONAL MEMORY DEVICE WITH THROUGH-STACK CONTACT VIA STRUCTURES AND METHOD OF MAKING THE SAME

A memory device includes an alternating stack of insulating layers and electrically conductive layers containing stepped surfaces in a contact region, a first stepped dielectric material portion overlying the stepped surfaces of the alternating stack, a memory opening vertically extending at least through each layer within the alternating stack, a memory opening fill structure located in the memory opening and containing a vertical stack of memory elements and a vertical semiconductor channel, and a bundled contact via structure vertically extending through the first stepped dielectric material portion and through a plurality of bottommost electrically conductive layers of the electrically conductive layers, and laterally contacting each of the plurality of the bottommost electrically conductive layers.