Characterization of hetero-interfaces between group III nitrides formed by PLD and various substrates

We have grown group III nitride epitaxial films on various substrates by pulsed laser deposition and investigated structural properties of the surfaces and the hetero-interfaces using grazing incidence angle X-ray reflectivity (GIXR) and atomic force microscopy (AFM). It has been found that hetero-interfaces between PLD AIN and conventional substrates such as Al2O3 and Si are quite abrupt (about 0.5 nm) probably due to a less reactive growth ambience. However, we observed a thin interfacial layer (less than 10 nm) at the hetero-interface between AIN and ( Mn,Zn)Fe2O4. The surface roughness of AIN is mainly determined by the extent of the lattice mismatch. It has been also found that the roughness at the hetero-interface between GaN and AIN formed by PLD coincides with the surface roughness of the AIN layer. (C) 2002 Elsevier Science B.V. All rights reserved.