Conductive atomic force microscopy studies on dielectric breakdown behavior of ultrathin Al2O3 films

Abstract

Ultrathin films of Al2O3 prepared by atomic layer deposition have been subjected to local electrical stress analysis using conducting atomic force microscopy. The loss of local dielectric integrity through current leakage in these extremely thin films is studied using scanning spreading resistance imaging. Our experimental results shows that repeated voltage stress progressively increases number of leakage spots. While the density of leakage spots increase with higher applied bias for thin oxide films, initial increase and reduction in leakage spots are observed for thick films.