Phase change memory cell with high read margin at low power operation

A memory cell device comprising:

• a first electrode;
• phase-change material adjacent the first electrode;
• a second electrode adjacent the phase-change material;
• a diffusion barrier adjacent the phase-change material;
• and
• isolation material adjacent the diffusion barrier for thermally isolating the phase-change material,
• wherein the diffusion barrier prevents diffusion of the phase-change material into the isolation materia1,
• wherein the isolation material comprises a dielectric material that limits the heat leakage from the phase change material, and
• wherein the dielectric material comprises a porous oxide film having a thermal conductivity between 0.1 and 0.8 W/mk.