Al2O3 thin films from aluminium dimethylisopropoxide by metal-organic chemical vapour deposition

This paper focuses on the use of aluminium dimethylisopropoxide as a novel precursor for the chemical vapour deposition of alumina thin films. The fra gmentation pattern of this compound was studied by mass spectrometry, while its volatility and decomposition route were analysed by in-line FT-IR spec troscopy. Aluminium oxide films were grown in the temperature range 540-600 degrees C at a total pressure of 100 Pa in a nitrogen-oxygen atmosphere. A kinetic model was developed which includes an overall heterogeneous reacti on and a parasitic one in the gas phase with apparent activation energies o f 130 kJ mol(-1) and 209 kJ mol(-1) respectively. The microstructure, compo sition and morphology of the obtained layers were analysed respectively by X-ray diffraction, X-ray photoelectron spectroscopy and atomic force micros copy. The aluminium oxide films obtained were transparent, amorphous, stoic hiometric, carbon-free and smooth. An island growth was proposed. Uniform g rowth rates along the reactor of 16, 32 and 57 nm min(-1) are found at depo sition temperatures in the range of 560-570 degrees C, at precursor evapora tion temperatures of 15, 25 and 35 degrees C respectively.