Defects induced anomalous breakdown kinetics in Pr2O3 by micro- and nano-characterization

Praseodymium based dielectric thin films have been deposited by metal-organic chemical vapour deposition (MOCVD). The Weibull slope and the characteristic time of the dielectric breakdown (BD) have been determined at nanometer scale by conductive atomic force microscopy (C-AFM). An anomalous behaviour for the dielectric BD has been found. Its physical behaviour has been described taking into account the electrical properties investigated by nanoscopic measurements performed by scanning capacitance microscopy (SCM). Current density-voltage (J-V) measurements have been carried out at different temperatures (from 100 to 200 degrees C). At low electric fields, a slight dependence of J -V characteristics in function of both temperature and electric field has been observed, while a relatively strong dependence has been found at high fields. The calculation of the activation energies for conduction mechanisms in both field regions pointed out the presence of deep defects that play a relevant role in the BD kinetics. (C) 2007 Elsevier Ltd. All rights reserved.