Effect of Sb2Se on phase change characteristics of Ge2Sb2Te5

In this paper, the effect of Sb2Se on the phase change characteristics of Ge2Sb2Te5 (GST) is systemically studied for applications in phase-change random access memory (PRAM). The crystallization temperature of Sb2Se-GST increases with increasing Sb2Se content, while the archival life of the amorphous state first decreases and then increases. The phase transition from face-centered-cubic (FCC) to hexagonal (HEX) is suppressed when the Se atomic percentage is higher than 9% for Sb2Se-GST films. The wide band gap and high value of B-1/2 lead to a contrast in resistance of about five orders of magnitude between the amorphous and crystalline states. Compared with GST, Ge4Sb52Te9Se35 shows a high crystallization temperature, a wider band gap and a fast switching speed, suggesting it is a potential candidate for PRAM.