Phase changeable memory devices include an integrated circuit substrate and first and second storage active regions on the integrated circuit substrate. The first and second storage active regions have a first width and a second width, respectively. A transistor active region on the integrated circuit substrate is between the first and second active regions, the first and seconds widths being less than a width of the transistor active region.
A process for manufacturing a phase change memory array, includes the steps of: forming a plurality of PCM cells, arranged in rows and columns; and forming a plurality of resistive bit lines for connecting PCM cells arranged on a same column, each resistive bit lines comprising a respective phase change material portion, covered by a respective barrier portion. After forming the resistive bit lines, electrical connection structures for the resistive bit lines are formed directly in contact with the barrier portions of the resistive bit lines.