Chemical composition changes across the interface of amorphous LaScO_3 on Si(001)

摘要

An amorphous, high-dielectric-constant LaScO_3 film was deposited directly on Si (001) by molecular-beam deposition at ～100 ℃. Various transmission electron microscopy techniques were applied to study the interface at atomic resolution. We observed an ～3.5-nm-thick interfacial layer that was not previously detected with other techniques. The interfacial layer contained defects and its density changes gradually. The interface was not only structurally sharp but also chemically sharp within the detection limit of the experimental methods. The chemical composition of the bulk oxide film was stoichiometric, but the interfacial layer was oxygen poor.