Fabrication of a wider bandgap θ-Al2O3 by oxidation of ultrathin AlN films for leakage current reduction

Abstract

Abstract Aluminum oxide (Al2O3) films were fabricated through the oxidation of ultrathin aluminum nitride (AlN) films. The fabricated films exhibited a leakage current reduction compared to that of conventional Al2O3 films fabricated using atomic layer deposition. This reduction in the leakage current can be attributed to the formation of θ-Al2O3, which has a wider-bandgap than γ-Al2O3. The formation of θ-Al2O3 was attributed to the residual stress caused by the oxidation of the AlN thin films.