MEMORY DIE CONTAINING THROUGH-MEMORY-LEVEL VIA STRUCTURE AND METHODS FOR MAKING THE SAME

An alternating stack of insulating layers and spacer material layers is formed over a substrate. At least one dielectric material portion is formed over the substrate adjacent to the alternating stack. Memory stack structures are formed through the alternating stack. A trench extending through the alternating stack and a via cavity extending through the at least one dielectric material portion are formed using a same anisotropic etch process. The via cavity is deeper than the trench and the via cavity extends into an upper portion of the substrate. The sacrificial material layers are replaced with electrically conductive layers using the trench as a conduit for an etchant and a reactant. A trench fill structure is formed in the trench, and a via structure assembly is formed in the via cavity using simultaneous deposition of material portions. A bonding pad may be formed on the bottom surface of the via structure assembly.