Epitaxial growth and relaxation of γ-Al2O3 on silicon

0.5–10 nm-thick single crystal γ-Al2O3 films was epitaxially grown, at high temperature, on Si(001) and Si(111) substrates using electron-beam evaporation techniques. Reflection High Energy Electron Diffraction studies showed that the Al2O3 films grow pseudomorphically on Si (100) up to thickness of 2 nm. For higher thicknesses, a cubic to hexagonal surface phase transition occurs. Epitaxial growth and relaxation were also observed for Si(111). The film surfaces are smooth and the oxide–Si interfaces are atomically abrupt without interfacial layers.