Three-dimensional memory device containing conformal wrap around phase change material and method of manufacturing the same

A phase change memory device, comprising:

• word lines comprising electrically conductive layers that extend along a first horizontal direction and are laterally spaced apart along vertical direction and along a second horizontal direction, wherein each of the electrically conductive layers comprises a laterally alternating plurality of pad portions and wire portions having a lesser width than the pad portions in the second horizontal direction;
• a plurality of line trenches that laterally extend along the second horizontal direction and located vertically between neighboring pairs of pad portions of the electrically conductive layers, wherein an array of wire portions traverses each of the plurality of line trenches along the first horizontal direction;
• layer stacks of a phase change memory material layer and at least one threshold switch material layer, wherein each layer stack is wrapped around a corresponding wire portion of the electrically conductive layers located within one of the plurality of line trenches, the plurality of layer stacks creating a two-dimensional array of wrap around portions;
• and
• a plurality of bit lines located within a respective one of the plurality of line trenches, wherein each wrap around portion of the layer stacks is surrounded by a respective one of the plurality of bit lines within a vertical plane that is perpendicular to the first horizontal direction.