Ultrafast phase change speed and high thermal stability of antimony and zinc co-sputtering thin film for phase change random access memory application

Abstract

In this work, we fabricate the Sb54Zn46 thin film by pure antimony and zinc targets co-sputtering and analyze its phase change properties. The ten-years data retention of Sb54Zn46 thin film, being a good reflection of thermal stability, is improved to 119 °C from 24 °C of pristine antimony thin film, which is much higher than that of the traditional phase change material Ge2Sb2Te5 (85 °C). The increased thermal stability of Sb54Zn46 thin film mainly derives from the formation of the strong Sb-Zn bond stretching mode during crystallization. In addition, the phase change speed of Sb54Zn46 thin film measured in device test increases to 10 ns, which is also much faster than that of the traditional phase change material Ge2Sb2Te5 (100 ns). These results illustrate that the fast phase change speed of Sb54Zn46 thin film is mainly ascribed to the Sb-rich atomic environment and the growth-dominant crystallization mechanism. Our work substantiates the co-sputtering Sb54Zn46 thin film can ensure fast phase change speed while effectively increasing its thermal stability.