Ge-rich PCM cell endurance study versus programming pulse shape

Ge-rich chalcogenide alloys are recently being inve stigated due to their retention improvement perform ances with respect to conventional Ge 2Sb 2Te 5. In this scenario it is important to explore also th e other characteristics of this alloys as endurance behavior. . We present a study of Ge-rich PCM cell endurance with respect to programming pulse shape. . In order to understand physical mechanisms critical for cycling, two different approaches for SET prog ramming have been considered, where crystalline phase is obtaine d starting or not from the melted material. A 90nm Wall-like cell is considered. Endurance performances are studied as f unction of energy and power of applied pulses. We will show that endurance is correlated either with pulses energy o r power depending on the SET programming approach. Improved endurance of integrated devices is obtained if SET pulse is engineered according to the “crystallize o nce” approach, where the maximum temperature is well below the melting point. These results are in agreement with tho se already found for conventional Ge 2Sb 2Te 5, thus confirming basically the same physical mecha nisms driving endurance fails in case of Ge-rich alloys.