An alternating stack of insulating layers and sacrificial material layers is formed over a substrate. Memory openings are formed through the alternating stack. Protruding tip portions are formed on each of the sacrificial material layers around the memory openings. A plurality of insulating spacers is formed within each memory opening between each vertically neighboring pair of tip portions of the sacrificial material layers. A phase change memory material and a vertical bit line are formed within each of the memory openings. The phase change memory material can be formed as a vertical stack of discrete annular phase change memory material portions, or can be formed as a continuous phase change memory material layer. Each of the sacrificial material layer can be replaced by an electrically conductive layer.