X-ray Photoelectron Spectroscopy Depth Profiling of Aluminium Nitride Thin Films

Aluminium nitride thin films grown at room temperature on degenerate silicon (conducting) substrates have been studied using XPS. The hydrolysis layer at the surface of the AlN was examined using valence band measurements, and the effect of 5 kV argon ion milling used to remove the hydrolysis layer was scrutinized using angle-resolved XPS. The N/Al ratios found from the angle-resolved measurements indicate nitrogen depletion from the surface of the milled samples, whereas O/Al ratios indicate no such depletion of oxygen. After argon ion milling, carbon uptake from the ultrahigh vacuum analysis chamber was found to be significant.