The present invention relates to a process of forming a phase-change
memory. A lower electrode is disposed in a first dielectric film. The
lower electrode comprises an upper section and a lower section. The upper
section extends beyond the first dielectric film. Resistivity in the
upper section is higher than in the lower section. A second dielectric
film is disposed over the first dielectric film and has an upper surface
that is coplanar with the upper section at an upper surface.