CVD of Al2O3 thin films using aluminum tri-isopropoxide

A stagnation point cold-wall reactor was used for the CVD of corundum alumina (alpha-Al2O3) on metallic substrates. Depositions were carried out under low pressure using the thermally induced pyrolytic oxidation of aluminum tri-isopropoxide (ATI). The effects of the substrate temperature (300-1080degreesC) and the total pressure (50-250 mbar) on the growth rate and morphology of the deposits were investigated. An excess of oxygen facilitates the formation of dense alumina films. Precursor depletion was prevented using high gas velocity, low ATI concentration, and a high temperature gradient. X-ray diffraction (XRD) analysis provided evidence of corundum alumina deposition at substrate temperatures above 1000degreesC.