Selective tungsten growth for word lines of a three-dimensional memory device

A three-dimensional memory device comprising:

• an alternating stack of insulating layers and electrically conductive layers located over a substrate;
• memory stack structures extending through the alternating stack, each of the memory stack structures including a memory material layer, a tunneling dielectric, and a vertical semiconductor channel;
• a pair of backside trenches extending through the alternating stack and including respective backside contact via structures contacting a respective portion of the substrate;
• metallic liner layers laterally extending between the pair of backside trenches;
• and
• polycrystalline aluminum oxide liners located between a respective one of the metallic liner layers and a respective one of the electrically conductive layers, wherein the polycrystalline aluminum oxide liners are laterally spaced from each of the pair of backside trenches by a respective lateral offset distance.