Effect of Sb2Se on phase change characteristics of Ge2Sb2Te5

Abstract

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.