By means of a metal organic chemical vapour deposition, starting from a single precursor compound [tBuOAIH(2)](2), an aluminium/aluminium hydride-oxide composite has been synthesized in thin layers. Electron micrographs indicate self-similarity. A detailed analysis by small angle neutron scattering directly yields a surface fractal microstructure with a fractal dimension of 2.26; in the framework of a surface fractal model we determine the relevant particle dimensions and their size distribution.