Effect of nitrogen plasma treatment on the characteristics of AlN thin films

Aluminum nitride (AlN) thin films have been deposited on silicon (100) wafers by radio frequency reactive magnetron sputtering. The as-deposited AIN films are less dense and have a higher dangling bonds percentage than AIN single crystals. In addition the surface of as-deposited film is too rough to apply to electronic devices. In order to overcome those limitations, nitrogen plasma treatment (NPT), as a novel heat-treatment, is used for the first time in this work. As NPT time increases, surface roughness is dramatically reduced and, at the same time, the Al-N bonds in the films become stable. As a result, chemical stability of nitrogen-plasma-treated AlN films increases sharply in a strongly alkaline solution, 2 M KOH. Furthermore, the interactions between AIN films and nitrogen plasma result in the improvement of electrical properties of AIN films, i.e., the leakage current density measured by I-V method is reduced. (C) 2000 The Electrochemical Society. S0013-4651(00)02-048-6. All rights reserved.