A self-aligned process to fabricate a "metal-quantum dot-metal" structure is presented, based on an "electron beam lithography, thin film deposition and dry etching process". The sacrificial layers used can improve the lift-off process, and novel lithography layouts design can improve the mechanical strength of the fabricated nanostructures. The superiority of the self-aligned process includes low request for overlay accuracy, high compatibility with a variety of materials, and applicable to similar structure devices fabrication. Finally, a phase change memory with fully confined phase-change material node, with the length width height of 255 45 30 nm 3 was demonstrated.