Growth kinetics and physical characterisation of Si1-xGexO2 films obtained by plasma assisted oxidation

Oxides of Sii-xGex alloys have been grown using the method of plasma assisted, anodic oxidation at temperatures < 100 degrees C. The growth kinetics have been analysed as a function of Ge concentration to obtain information on the O- ion mobility, mu, in the oxide. We observe mu(SiO2) < mu(GeO2) < mu(Sii-xGexO2) for 0.0 < x < 1.0. Infrared absorption spectroscopy has been used to examine the network bonding, it shows that the numbers of Si-O-Si, Si-O-Ge and Ge-O-Ge bonds do not follow those expected on the basis of simple statistics related to the relative concentrations of Si and Ge. Auger electron spectroscopy and secondary ion mass spectroscopy reveal that the anodic oxides are spatially inhomogeneous being composed of mixtures of SiO2, GeO2 and Sii-xGexO2, consistent with the results of infrared analysis. (C) 1999 Elsevier Science B.V. All rights reserved.