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

Among chalcogenides for phase-change memory, Sb
2
Te
3
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 Sb
2
Te
3
thin films with substrate dependency. Comparatively, thin film growth trends of ALD Sb
2
Te
3
on SiO
2
and W substrate were studied by observing transformation of crystal structures, and trends in electrical resistivity. On SiO
2
, 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.