Crystallization properties of Ga-Sb phase change al loys

Ga-Sb alloys are potential candidates for Phase Change Random Access Memory (PCRAM) applications. Ga-Sb alloys of variable compositions including the stoichi ometric GaSb and several Sbrich compositions were studied using static laser testing and tim e-resolved X-ray diffraction. It was found that the stoichiometric alloy has an unusual inverse optical cont rast compared to typical phase change materials as the crystalline phase has lower reflecti vity than the amorphous phase. Slightly Sbrich alloys show decrease in reflectivity upon crystallization at lower temperature but increase in reflectivity at higher temperature which are related to GaSb c rystallization and subsequent Sb segregation, respectively. Very Sb-rich materials exhibit positi ve optical contrast only, similar to conventional phase change materials.