Study of crystallization and thermal stability of superlattice-like SnSb4-GeTe thin films

In this study, two series of superlattice-like (SLL) SnSb4-GeTe thin films with mono-period and multi-period stacks are fabricated. [SnSb4(10 nm)-GeTe(40 nm)]1 and [SnSb4(2 nm)-GeTe(10 nm)]4 thin films are the most representative ones in terms of mono-period and multi-period stacking group, showing good crystallization speed and distinct thermal stability. The results illustrate that the similar crystallization speed (< 5 ns) exists in both [SnSb4(10 nm)-GeTe(40 nm)]1 and [SnSb4(2 nm)-GeTe(10 nm)]4 thin films. In terms of thermal stability, the ten years data retention of [SnSb4(2 nm)-GeTe(10 nm)]4 and [SnSb4(10 nm)-GeTe(40 nm)]1 thin film are 102.3 °C and 149.5 °C respectively. The difference of the stability mainly derives from the different stacking number of SnSb4-GeTe interface, giving rise to the different degrees of interaction between pre-precipitates Sb (crystallization) and GeTe (amorphous).