Interfacial-layer-free growth of yttrium oxide on germanium by understanding initial surface reactions

► Interfacial-layer-free growth of yttrium oxide on germanium through a novel layer-by-layer method at room temperature. ► Insights on initial surface reactions and reaction pathways in the formation of yttrium germanate. ► Provided evidence for the metal-induced weakening mechanism to explain intermixing of yttrium and germanium. ► Provided understanding of effects of different oxidation in oxide growth.