REAL-TIME EMISSION-SPECTROSCOPY DURING DEPOSITION OF GERMANIUM OXIDE-FILMS BY LASER ABLATION

The dynamics of the plume produced during excimer laser deposition of germanium oxide films by excimer laser ablation of a Ge target in the presence of an oxygen atmosphere is studied by real time emission spectroscopy. It is found that the velocity of the species in the plume (both neutral and ionized) remains unaffected under the presence of an oxygen pressure ranging from 10(-4) up to 1 mbar, whereas the oxygen content of the films increases with the oxygen pressure up to the stoichiometric value (GeO2) for pressures higher than 5 X 10(-3) mbar. The spectral emission features show no evidence of oxidized species in the gas phase even at high oxygen pressures. It is then concluded that the incorporation of oxygen to the growing film occurs mainly by reactions at the substrate site.