Metalorganic molecular beam epitaxy of γ-Al2O3 films on Si at low growth temperatures

Heteroepitaxial growth of γ-Al2O3 films was performed successfully onto (100) and (111) Si substrates at low substrate temperatures between 720 and 800 °C by metalorganic molecular beam epitaxy using N2 bubbled Al(CH3)3 and N2O. Using in situ reflection high-energy electron diffraction, the orientation relationships between epitaxial γ-Al2O3 films and Si substrates were found to be (100) γ-Al2O3//(100) Si with [11̄0] γ-Al2O3//[11̄0] Si and (111) γ-Al2O3//(111) Si with [11̄2̄] γ-Al2O3//[11̄2̄] Si. The stoichiometry of the grown films was found similar to that of Al2O3 from Auger signals.