Characterization of MgO thin films grown by rf-sputtering

Thin films of MgO were grown on an Si(1 0 0) substrate at 1000 K by rf-sputtering using two different targets: Mg and MgO. The total pressure during the growing process was maintained at 7.0 x 10(-3) mbar and the O-2 to Ar percentage was varied from 5% to 50%. X-ray diffraction measurements indicate that two different crystalline structures are formed depending on whether the target was Mg or MgO. In MgO films grown using an Mg target, the diffraction peak corresponds to MgO(2 0 0) of the rock salt structure, and in MgO films grown with an MgO target the diffraction peak corresponds to MgO(400) of the cubic spinel structure. In both structures, the maximum intensity of the diffraction peak occurs when the oxygen to argon percentage is 20%. The surface stoichiometry of both types of films was determined by Auger electron and X-ray photoelectron spectroscopy. X-ray photoelectron spectroscopy corroborates the presence of OH radicals. (C) 2002 Elsevier Science Ltd. All rights reserved.