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

Abstract
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.