Epitaxial oxide thin films on Si(001)

Over the years, the development of epitaxial oxides on silicon has been a g reat technological challenge. Amorphous silicon oxide layer forms quickly a t the interface when the Si surface is exposed to oxygen, making the intend ed oxide heteroepitaxy on Si substrate extremely difficult. Epitaxial oxide s such as BaTiO3 (BTO) and SrTiO3 (STO) integrated with Si are highly desir able for future generation transistor gate dielectric and ferroelectric mem ory cell applications. In this article, we review the recent progress in th e heteroepitaxy of oxide thin films on Si(001) substrate by using the molec ular beam epitaxy technique at Motorola Labs. Structural, interfacial and e lectrical properties of the oxide thin films on Si have been characterized using in situ reflection high energy electron diffraction, x-ray diffractio n, spectroscopic ellipsometry, atomic force microscopy, Auger electron spec troscopy, x-ray photoelectron spectroscopy, high-resolution transmission el ectron microscopy, high-resolution transmission electron energy loss spectr oscopy, capacitance-voltage and current-voltage measurement. We also presen t the transistor results and address the impact of the epitaxial oxide film s on future generation metal-oxide-semiconductor field effect transistors. (C) 2000 American Vacuum Society. [S0734-211X(00)00504-7].