Preparation and properties of TiN and AlN films from alkoxide solution by thermal plasma CVD method

Single phase TiN and AIN films were prepared on a Si wafer from titanium tetra-etoxide and aluminum tri-butoxide solutions dissolved in ethanol and toluene, respectively, using an Ar/N-2/H-2 radio-frequency (r.f.) inductive thermal plasma chemical vapor deposition (CVD) method. The films were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, measurement of electrical resistivity and Vickers microhardness. Factors affecting the formation of the films (lattice parameter, chemical composition, oxygen/carbon content, and deposition rate of the films) were examined in terms of the N-2 how rate (2.5-4.5 sim), substrate temperature (300-700 degrees C), feed rate of the solution (0.025-0.3 mi/min), and the mole ratio of the alkoxide solution (1:1-1:3), The optimum conditions for preparation of TiN films produced a film 0.2-3 mu m thick with an oxygen content of 8 at.% and a free carbon content of 4 at.%, showing an electrical resistivity of 370 ydL cm. The optimum conditions for A1N films produced a film 0.3 ym thick containing 14 at.% oxygen and 8 wt.% carbon. The deposition rate of the TiN film was determined to be 30-35 nm/min. The Vickers microhardness of the TiN and A1N films was found to be 10 +/- 1 and 13 +/- 3 GPa, respectively. (C) 2000 Elsevier Science S,A. All rights reserved.