Crystallization Behavior and Physical Properties of Sb-Excess Ge2Sb2 + x Te5 Thin Films for Phase Change Memory (PCM) Devices

The crystallization behavior of antimony(Sb)-excess Ge 2 Sb 2+x Te 5 was examined. Sb-excess GST showed crystallization (T c ) and melting (T M ) temperatures of 205 and 550°C, respectively, slightly higher T C and lower T M values than stoichiometric Ge 2 Sb 2 Te 5 compounds. It also showed a substantially different crystallization behavior compared to the stoichiometric Ge 2 Sb 2 Te 5 composition. The resulting Sb-excess GeSbTe thin film showed a grain growth dominated crystallization behavior.