EFFECTS OF ELECTRODE MATERIALS AND ANNEALING AMBIENTS ON THE ELECTRICAL-PROPERTIES OF TIO2 THIN-FILMS BY METALORGANIC CHEMICAL-VAPOR-DEPOSITION

In this work, we investigate the effects of the top electrode material s and annealing ambients on the electrical properties of chemical-vapo r-deposited (CVD) TiO2 films. Experimental results indicate that the l eakage current is mainly determined by the work function of electrode materials before sintering. The capacitor with TaN top electrode revea ls the least leakage. After 450 degrees C and 800 degrees C sintering in N-2, owing to its thermal stability, WN is found to be the optimal material for withstanding high-temperature thermal treatment. From the annealing ambient results, N2O was more effective than O-2 in reducin g leakage current, and furnace annealing in N2O (FN2O) produces the sm allest leakage. Such a phenomenon is primarily owing to the reduction of oxygen vacancies and carbon concentration in TiO2 by the atomic oxy gen generated by the dissociation of N2O during the thermal cycle, the reby improving film quality.