Phase transition characteristics of Al-Sb phase change materials for phase change memory application
The crystallization behavior of Al-Sb thin films is investigated for phase change memory application. The crystallization temperature and optical band gap of the amorphous material increase with Al content. The thermal stability and randomness in atomic configuration of the films are enhanced considerably. The shift of Raman modes associated mainly with Sb upon phase transformation is observed, and the co-existence of Sb-rich crystalline regions and Al-rich amorphous matrix is confirmed, revealing the amorphous nature of most Al components. Three distinct resistance levels are achieved in the devices using Al50Sb50, suggesting the potentiality for multilevel data storage application of the materials.