LAUSR

Abstract Epitaxial growth of AlN films on sapphire substrates prepared by halide vapor phase epitaxy (HVPE) using N2 as N source is reported. The effects of V/III ratio on the growth rate, surface morphology and crystal quality of AlN films are systematically investigated. Compared with traditional HVPE using NH3 as N source, the growth rate of AlN films here increased linearly instead of decrease exponentially as increasing input V/III ratio. The surface morphology of the as-grown AlN films exhibited a periodic stripe structure at low V/III ratio and exhibited a pit-like or grid-like structure at high V/III ratio. The effect of V/III ratio on crystal quality varied under different HCl flow rate. The full width at half maximum (FWHM) of the (0002)- and (10-12)- plane X-ray rocking curves (XRCs) were 108–480 and 495–1083 arcsec, respectively, depending on both the V/III ratio and the growth rate of AlN films.