Nitriding of aluminium 2011 using a radio frequency plasma at higher power levels (500 and 700 W) and lower substrate temperature (500 degrees C) resulted in higher AlN/Al2O3 ratios than obtained at 100 Wand 575 degrees C. AlN/Al2O3 ratios derived from X-ray photoelectron spectroscopic analysis (and corroborated by heavy ion elastic recoil time of flight spectrometry) for treatments preformed at 100 (575 degrees C), 500 (500 degrees C) and 700 W (500 degrees C) were 1.0, 1.5 and 3.3, respectively. Scanning electron microscopy revealed that plasma nitrided surfaces obtained at higher power levels exhibited much finer nodular morphology than obtained at 100 W. (c) 2006 Elsevier B.V. All rights reserved.