Atomic-scale Crystal Phase Transformation of Atomic Layer Deposited Antimony Telluride Thin Films with Substrate-dependent Orientations

Abstract

Among chalcogenides for phase-change memory, Sb2Te3 is attracting attention for its huge potential, along with recent demands for atomic layer deposition (ALD). We aimed to study atomic-scale thin film growth and phase transformation of ALD Sb2Te3 thin films with substrate dependency. Comparatively, thin film growth trends of ALD Sb2Te3 on SiO2 and W substrate were studied by observing transformation of crystal structures, and trends in electrical resistivity. On SiO2, predominant amorphous phases at initial stage were observed, followed by polycrystalline island growth with randomly oriented grains. However, on crystalline W, the highly out-of-plane (00l) orientations and layer-by-layer growth was found.