Enhanced Thermal Stability and Suppressed Resistance Drift of Sb₇₀Se₃₀ Phase-Change Thin Films by Adding HfO₂ Interlayers

We have prepared Sb₇₀Se₃₀/HfO₂ (SS/HO) multilayer thin films by magnetron sputtering method and studied the effect of the HO interlayer on the phase transition behavior of the SS thin films. The results indicate that the introduction of the HO interlayer not only enhances the crystallization temperature, data retention capability, and crystallization activation energy of the SS thin film but also reduces resistance drift and suppresses its crystallization. X-ray photoelectron spectroscopy shows that Sb atoms exhibit a preference for bonding with O atoms at multilayer interfaces, thereby forming stronger Sb–O bonds, which contribute to the thermal stability of multilayer thin films. The Raman results further confirm a reduction in bond length and an increase in bond energy. Furthermore, the SS/HO thin films exhibit enhanced substrate adhesion and a more uniform surface morphology. The study of crystallization kinetics reveals that the crystallization mechanism of SS/HO thin films is predominantly governed by one-dimensional growth. Moreover, the lower threshold switching voltage (1.65 V) in SS/HO thin films contributes to a reduction in power consumption during SET operations. All these findings collectively demonstrate that SS/HO thin films are anticipated to be excellent candidate materials for phase-change memory applications.