Annealing of ZrAlxOy ultrathin films on Si in a vacuum or in O-2

ZrAlxOy films deposited on Si were submitted to thermal annealings in a vac uum or an oxygen atmosphere. Elemental compositions as functions of depth w ere established using ion beam techniques such as Rutherford backscattering spectrometry and narrow nuclear resonance profiling. In addition, chemical composition profiles were obtained by angle-resolved X-ray photoelectron s pectroscopy. The as-deposited film is amorphous, has an abrupt interface wi th the Si substrate, and its chemical composition is a double oxide with ap proximate stoichiometry Zr4AlO9. Atomic transport and chemical reaction ind uced by thermal annealing were investigated by the above mentioned techniqu es and by low energy ion scattering spectroscopy. We have observed that Al, O, and Si migrate during annealing, whereas Zr is essentially immobile. Ox ygen from the gas phase was heavily incorporated into the oxide films durin g annealing in O-2, mostly in exchange for previously existing oxygen. (C) 2001 The Electrochemical Society.