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초록

Antimony telluride (Sb2Te3) has emerged as a promising candidate for the switching component in phase change memory (PCM) owing to its rapid crystallization speed. Since the device performance of PCM is closely related to the constituent phases of the switching component, a comprehensive understanding of its nanoscale structure is essential for optimizing device fabrication process. In this study, we systematically investigate the substrate-dependent growth behavior and phase evolution of Sb2Te3 thin films grown by atomic layer deposition (ALD) on SiO2 and W substrates-representative materials commonly used as insulator and metallic plug in PCM architecture, respectively. On the SiO2 substrate, a predominant amorphous phase is observed due to the formation of SbOx and TeOx interfacial compounds, followed by polycrystalline island growth beyond a critical thickness of 10 nm. In contrast, films grown on the W substrate exhibit a pronounced out-of-plane-oriented layered structure from the initial growth stage due to the formation of a Te-terminated surface (quasi-monolayer of Te). These nanoscale observations elucidate the substrate effects on the growth behavior and phase evolution during the ALD process, offering valuable insights and practical guidelines for the ALD process of Sb2Te3.