CHEMICAL-VAPOR-DEPOSITION OF TIO AND TI2O3 FROM TICL4 H-2/CO2 GAS-MIXTURES/

Chemical vapour deposition of TiO and Ti2O3 from TiCl4/H-2/CO2 gas mix tures was studied. A temperature of 1000 degrees C and pressures in th e range (13-6.7) x 10(3) Pa were utilized. Mainly silica was used as s ubstrate material and in the case of Ti2O3 (01 $($) over bar$$ 12) sap phire was also employed. TiO consisted of submicron well-shaped crysta llites. A very porous interface between the silica and the TiO layer w as observed. Ti2O3 was composed of rounded crystals with voids in betw een. No porous interface was observed in this case. X-ray photoelectro n spectroscopy analysis revealed that Si was incorporated in the films . Prior to the deposition experiments, thermodynamic calculations util izing the free energy minimization technique were performed and calcul ated chemical vapour deposition phase diagrams for oxides in the compo sition range TiO-Ti8O15 were constructed.