A memory device having a vacuum jacket around the first electrode element
for improved thermal isolation. The memory unit includes a first
electrode element; a phase change memory element in contact with the
first electrode element; a dielectric fill layer surrounding the phase
change memory element and the first electrode element, wherein the
dielectric layer is spaced from the first electrode element to define a
chamber between the first electrode element and the dielectric fill
layer; and wherein the phase change memory layer is sealed to the
dielectric fill layer to define a thermal isolation jacket around the
first electrode element.
