The influence of experimental variables in combination with catalysis on the growth and microstructure of chemically vapour deposited kappa -Al2O3 was investigated. The Al2O3 coatings were deposited in the temperature range of 800-1000 degreesC and at pressures of 50-400 mbar. Hydrogen sulfide (H2S) was used as a doping/catalysing agent. General deposition characteristics of kappa -Al2O3 as a function of temperature, pressure and H2S concentration are reported. In addition to scanning electron microscopy and X-ray diffraction, the microstructure and chemistry of the kappa -Al2O3 layers were analysed using transmission electron microscopy. The growth rate of kappa -Al2O3 could be strongly enhanced by applying H2S doping and reasonable deposition tares for kappa -Al2O3 could be obtained at 800 degreesC. Relatively very high growth rates could be obtained by increasing the total pressure simultaneously with H,S doping. Higher deposition pressure, however, increased the contribution of the homogenous gas phase reaction resulting in unacceptable thickness variations. In general, kappa -Al2O3 deposited at different process conditions did not exhibit any pronounced microstructural or morphological differences, except at the deposition temperature of 800 degreesC together with at higher doping levels (H2S > 0.8%). Under these experimental conditions gamma -Al2O3 was obtained. Enrichment of sulfur could be confirmed to occur in gamma -Al2O3 while no sulfur was found in kappa -Al2O3. Production-scale aspects concerning deposition of kappa -Al2O3, and alpha -Al2O3 will be dealt with.