The optimization effect of titanium on phase change property of SnSb4 thin films for phase change memory application

Titanium doped SnSb4 phase-change thin film has been experimentally investigated for phase-change random access memory (PCRAM). The crystallization temperature, amorphous/crystalline resistance, and data retention of the SnSb4 thin film can be significantly enhanced by doping titanium, improving the thermal stability of the amorphous state and reducing power consumption. The effect of titanium doping on electrical transport in the thin film was explored with by Hall system. The X-ray diffraction and transmission electron microscopy confirmed that the grain size of the thin film was reduced as the titanium content increased. Grain refinement improved density changes of thin films before and after phase transition. The consequent change of chemical bonding states after adding titanium indicated that Ti was bonded to Sb in the SnSb4 lattice structure, respectively, wrapped around the Sb grains in an amorphous state. PCRAM cells based on the Ti0.10SnSb4 thin film can be realized with a whole operation window by 50ns width pulse, and the operating power consumption was lower than that of Ge2Sb2Te5 (GST) PCRAM cell of similar dimensions.