Al(2)O(3) films with thickness ranging from 20 to 300 nm are grown in a home-made reactor using atomic layer deposition with trimethylaluminum and water on different semiconductor substrates. The deposited films are investigated in terms of composition and electrical properties. Annealing treatments appear necessary in order to obtain films with good insulating properties, although the same treatments do not affect the stoichiometry of the main components. (C) 2008 Elsevier B.V. All rights reserved.