Abstract: An alternating stack of insulating layers and sacrificial material layers is formed with stepped surfaces. Sacrificial metal plates are formed on the top surfaces of the sacrificial material layers, and a retro-stepped dielectric material portion is formed over the sacrificial metal plates. Contact via cavities are formed through the retro-stepped dielectric material portion employing the sacrificial metal plates as etch stop structures. The sacrificial metal plates are replaced with portions of insulating spacer layers. Sacrificial via fill structures within remaining volumes of the contact via cavities. The sacrificial material layers are replaced with electrically conductive layers. The sacrificial via fill structures are replaced with portions of staircase-region contact via structures that contact the electrically conductive layers.

Abstract: An alternating stack of insulating layers and sacrificial material layers is formed with stepped surfaces. Sacrificial metal plates are formed on the top surfaces of the sacrificial material layers, and a retro-stepped dielectric material portion is formed over the sacrificial metal plates. Contact via cavities are formed through the retro-stepped dielectric material portion employing the sacrificial metal plates as etch stop structures. The sacrificial metal plates are replaced with portions of insulating spacer layers. Sacrificial via fill structures within remaining volumes of the contact via cavities. The sacrificial material layers are replaced with electrically conductive layers. The sacrificial via fill structures are replaced with portions of staircase-region contact via structures that contact the electrically conductive layers.

Abstract: An alternating stack of insulating layers and electrically conductive layers is formed over a substrate. Sidewalls of the electrically conductive layers are laterally recessed to form laterally recessed regions. After formation of a conformal barrier material layer in the laterally recessed regions and on the sidewalls of the insulating layers, an amorphous precursor memory material layer is deposited in lateral cavities and over the conformal barrier material layer. An anneal process is performed to selectively crystallize portions of the amorphous precursor memory material layer in the lateral cavities into crystalline memory material portions while not crystallizing portions of the amorphous precursor memory material outside the lateral cavities. Remaining amorphous portions of the amorphous precursor memory material layer are removed selective to the crystalline memory material portions. A vertical conductive line is formed on the crystalline memory material portions.