Metallorganic chemical vapour deposition of Al2O3 from Al(O-C3H7)3 via pyrolysis at low (∼280 °C) temperature was investigated with the goal of producing high quality Al2O3/p-InP (1 0 0) and Al2O3/p-Si (1 0 0) interfaces. Ellipsometer measurements of Al2O3 have determined the refractive index of the film to be about 1.55. Room temperature capacitance-voltage measurements were used to characterize the electrical properties of the structures after metal gate electrodes have been deposited. Low temperature conductance-voltage measurements were also carried out to investigate the quality of the Al2O3/InP interfaces. The interface state densities Al2O3/p-InP and Al2O3/p-Si determined from deep-level transient spectroscopy were approximately 1012 eV-1 cm-2 and 1011 eV-1 cm-2.