J. Phys. IV France 12 (2002) Pr4-139
MOCVD of aluminium oxide films using aluminium -diketonates as precursorsA. Devi, S.A. Shivashankar and A.G. Samuelson
Lehrstuhl fürAnorganische Chemie ll, Organometallics and Materials Chemistry, Ruhr-Universität Bochum, 44780 Bochum, Germany
Deposition of Al 20 3 coatings by CVD is of importance because they are often used as abrading material in cemented carbide cutting tools. The conventionally used CVD process for Al 20 3 involves the corrosive reactant AICl 3. In this paper, we report on the thermal characterisation of the metalorganic precursors namely aluminium tris-tetramethyl-heptanedionate [ Al(thd) 3] and aluminium tris-acetylacetonate [ Al(acac) 3] and their application to the CVD of Al 20 3 films. Crystalline A1203 films were deposited by MOCVD at low temperatures by the pyrolysis of Al(thd) 3 and AI(acac) 3. The films were deposited on a TiN-coated tungsten carbide (TiN/WC) and Si(100) substrates in the temperature range 500-1100 °C. The as-deposited films were characterised by x-ray diffraction, optical microscopy, scanning and transmission electron microscopy, Auger electron spectroscopy. The observed crystallinity of films grown at low temperatures, their microstructure, and composition may be interpreted in terms of a growth process that involves the melting of the metalorganic precursor on the hot growth surface.
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