Phase-change behavior in Si/Sb80Te20 nanocomposite multilayer films

Phase-change behavior in Si/Sb₈₀Te₂₀ nanocomposite multilayer films were investigated by utilizing in situ resistance measurements. It was found that the crystallization temperature increased firstly with increasing Si layer thickness within the multilayer films, and then remained almost unchanged at 170°C. The multilayer films have the merits of both good thermal stability and fast phase-change speed. An increase in crystallization temperature by around 95°C was observed for the multilayer films when the Sb₈₀Te₂₀ layer thickness was reduced to 3 nm. Cross-sectional transmission electron microscopy (TEM) observations revealed that Si/Sb₈₀Te₂₀ nanocomposite multilayer films had layered structures with clear interfaces. The reversible phase change between set and reset states was verified in phase-change random access memory (PCRAM) cell based on Si (1 nm)/Sb₈₀Te₂₀ (5 nm)]₁₇ multilayer film.