The electrical and structural properties of lanthanum aluminate (LAO) thin films, which were deposited by metallorganic chemical vapor deposition (MOCVD) method, were investigated and compared with those of lanthanum oxide (La2O3) thin films. The LAO films showed better thermal stability and leakage current density characteristic than La2O3 films. The equivalent oxide thicknesss of LAO film was larger than that of as-deposited La2O3 film and smaller for 900degreesC annealed film than La2O3 film. It is thought that the LAO film is a promising material which can be used as a high-k gate dielectric in future devices. (C) 2003 The Electrochemical Society.