A phase-change memory element is provided. The phase-change memory element includes: a first electrode formed on a substrate; a first dielectric layer, with an opening, formed on the first electrode, wherein the opening exposes a top surface of the first electrode; a pillar structure formed directly on the first electrode within the opening; an inner phase-change material layer surrounding the pillar structure, directly contacting the first electrode; a second dielectric layer surrounding the inner phase-change material layer; an outer phase-change material layer surrounding the second dielectric layer; a phase-change material collar formed between the second dielectric layer and the first electrode, connecting the inner phase-change material layer with the outer phase-change material layer; and a second electrode formed directly on the pillar structure, directly contacting the top surface of the inner phase-change material layer.