A semiconductor structure includes a memory-level assembly located over a substrate and including at least one alternating stack and memory stack structures vertically extending through the at least one alternating stack. Each of the at least one an alternating stack includes alternating layers of respective insulating layers and respective electrically conductive layers, and each of the electrically conductive layers in the at least one alternating stack includes a respective opening such that a periphery of a respective spacer dielectric portion located in the opening contacts a sidewall of the respective electrically conductive layers. At least one through-memory-level via structure vertically extends through each of the spacer dielectric portions and the insulating layers.