<0001>-oriented growth of AlN films on Si(111) by microwave plasma CVD with AlBr3-NH3-N-2 system

AIN thin films on Si(111) substrates were prepared by a microwave plasma activated chemical vapour deposition using NH3 and AlBr3 precursors. The films were highly (0002)-oriented on Si(111) properly pre-treated, and amorphous polycrystalline on non-treated surfaces. The growth rate and morphology of the films as a function of deposition parameters such as AlBr3 source and deposition temperatures, carrier gas flow rate, and system pressure were studied. The [0001]-oriented growth behaviour is discussed in terms of the system thermodynamics and surface adsorption-gas reaction growth model, associated with the effect of plasma ambient.