Effect of Ultraviolet Radiation on Properties of Ge₂Sb₂Te₅ Phase Change Films

With the expanding utilization of space technology, the stability of electronic components' performance in radiation environments has garnered significant attention. In this study, we prepared Ge₂Sb₂Te₅ phase change films and memory units on silicon substrates to explore the influence of ultraviolet (UV) radiation on their characteristics. The experimental findings revealed that UV irradiation at a power density of 450 mW/cm² decreased the amorphous resistance and thermal stability of Ge₂Sb₂Te₅ films, impeding their multistage storage performance. Nevertheless, the amorphous state could still undergo effective transformation into a crystalline state. Furthermore, UV irradiation triggered the photoelectric effect, narrowing the band gap and causing a redshift of the Raman peak in amorphous films. Remarkably, the surface properties of Ge₂Sb₂Te₅ films remained unchanged under irradiation. The phase change memory device based on Ge₂Sb₂Te₅ film retained its SET-RESET conversion capability at a pulse width of 100 ns post-UV irradiation, demonstrating resilience against UV radiation. This study offers the practical insights for the application of phase change memory in space radiation environments.