Development of robust interfaces based on crystalline γ-Al2O3(001) for subsequent deposition of amorphous high-κ oxides

This work reports on the development of thin crystalline γ-Al2O3(001) interfacial layers for subsequent deposition of amorphous high-κ oxides on Si(001). High quality and single crystal of γ-Al2O3 have been grown by Molecular Beam Epitaxy (MBE) on silicon. This γ-Al2O3/Si system leads to the formation of sharp and robust interfaces. They could be used for subsequent growth of amorphous high-κ oxides like lanthanum aluminate (LaAlO3) without forming interfacial reactions. Despite high temperatures and oxygen pressure conditions during deposition or post-annealing processes, the heterostructures are stable with respect to the silicon substrate up to 850°C.