Monocrystalline GaN thin films (500nm) were grown, using low-pressure metal-organic vapour-phase epitaxy, onto Si(111) substrates with an AlN buffer layer. Depending upon the AlN growth temperature, the growth mode of GaN could be either 2- or 3-dimensional. The 2-dimensional growth led to the best material, with a full-width at half-maximum of about 656arcsec for the (00•2) X-ray diffraction line in rocking curves for GaN. The dislocation density was of the order of 1010/cm2, and the surface root-mean-square roughness could be as low as 0.3nm.

Optimisation of AlN and GaN Growth by Metalorganic Vapour-Phase Epitaxy on Si(111). H.Lahrèche, P.Vennéguès, O.Tottereau, M.Laügt, P.Lorenzini, M.Leroux, B.Beaumont, P.Gibart: Journal of Crystal Growth, 2000, 217[1-2], 13-25