Effects of Ambient Nitrogen on Growth of Cubic AlN Films on Sapphire (0001) Substrates by Pulsed Laser Deposition

Cubic AlN films were prepared in nitrogen atmospheres by pulsed laser deposition. Their crystalline structures were precisely investigated using synchrotron X-ray diffraction techniques, and the effects of the nitrogen atmosphere on the growth were studied. At a pressure of 80 Torr, a series of diffraction peaks originating only in cubic AlN with a lattice constant of 7.913 {\AA} was observed in $\theta $-2$\theta$ measurements. On the other hand, at 30 Torr diffraction peaks from another cubic structure with a lattice constant of 4.045 {\AA} were observed. This indicates that the supply of a large amount of activated nitrogen ions on the surface is an important factor for the fabrication of c-AlN crystallites.