ALUMINUM NITRIDE SILICON-CARBIDE MULTILAYER HETEROSTRUCTURE PRODUCED BY PLASMA-ASSISTED, GAS-SOURCE MOLECULAR-BEAM EPITAXY

Pseudomorphic structures containing beta(3C)-SiC and 2H-AlN have been grown on vicinal alpha(6H)-SiC(0001) at 1050-degrees-C by plasma-assisted, gas-source molecular beam epitaxy. Reflection-high energy electron diffraction and cross-sectional high-resolution transmission electron microscopy showed all layers to be monocrystalline. The AlN layers were uniform in thickness. Defects in these layers initiated at steps on the 6H-SiC film. The 3C-SiC layers contained a high density of stacking faults and microtwins caused primarily by the interfacial stresses generated by the mismatch in lattice parameters between AlN and beta-SiC coupled with the very low stacking fault energy of SiC. This is the first report of the deposition of single crystal SiC/AlN/SiC thin film heterostructures on any substrate as well as the first report of the epitaxial growth of single crystal layers of binary materials with three different crystal structures.