X-RAY-REFLECTIVITY STUDY OF GE-SI-GE FILMS

Here we report on an x-ray specular reflectivity study of Ce-Si-Ge tri layers grown on Si(001) single-crystal substrate by ion beam sputterin g deposition at various substrate temperatures. The electron-density p rofile of the trilayer as a function of depth, obtained from x-ray-ref lectivity data, reveals an intermixing of Si and Ge. The x-ray-reflect ivity data have been analyzed using a scheme based on the distorted-wa ve Born approximation, and the validity of the analysis scheme was che cked using simulated data. Analyzed results provided information regar ding interdiffusion in this system. We notice that although the Si-on- Ge interface is sharp, a Si0.4Ge0.6 alloy is formed at the Ge-on-Si in terface.