An alternating stack of sacrificial material layers and insulating layers is formed over a substrate. Replacement of sacrificial material layers with electrically conductive layers can be performed employing a subset of openings. A predominant subset of the openings is employed to form memory stack structures therein. A minor subset of the openings is employed as access openings for introducing an etchant to remove the sacrificial material layers to form lateral recesses and to provide a reactant for depositing electrically conductive layers in the lateral recesses. By distributing the access openings across the entirety of the openings and eliminating the need to employ backside trenches for replacement of the sacrificial material layers, the size and lateral extent of backside trenches can be reduced to a level sufficient to accommodate only backside contact via structures.