An alternating stack of insulating layers and spacer material layers is formed over a substrate. Each of the first insulating layers and the first sacrificial material layers includes a respective horizontally-extending portion and a respective non-horizontally-extending portion. Memory stack structures are formed through the horizontally-extending portions of the alternating stack. Regions of the non-horizontally-extending portions of the sacrificial material layers are masked with patterned etch mask portions. Unmasked first regions of the non-horizontally-extending portions of the first sacrificial material layers are selectively recessed, and the sacrificial material layers with electrically conductive layers. Each electrically conductive layer can include a vertical plate region and a protrusion region that protrudes above the vertical plate region and having a narrower lateral dimension that the vertical plate region. Metal contact structures can be formed on the protrusion regions without contacting the vertical plate regions.