A memory device including a phase change element and a vacuum jacket. The
device includes a first electrode element; a phase change element in
contact with the first electrode element; an upper electrode element in
contact with the phase change element; a bit line electrode in contact
with the upper electrode element; and a dielectric fill layer surrounding
the phase change element and the upper electrode element, spaced from the
same and sealed by the bit line electrode to define a vacuum jacket
around the phase change element and upper electrode element.