POST-FABRICATION SELF-ALIGNED INITIALIZATION OF INTEGRATED DEVICES

Defining an active region of a phase change memory (PCM) cell including depositing a first layer of material having a first chemical composition. A second layer of material having a second chemical composition is deposited on top of the first layer of material. An electrical current pulse is applied to locally heat a region of the first layer of material and the second layer of material to cause at least one of an inter-diffusion and a liquid mixing of the first layer of material and the second layer of material. This results in in the PCM cell containing a self-aligned region that includes a phase change material that is a mixture of the first chemical composition and the second chemical composition.