Study of epitaxy by RHEED-TRAXS (total reflection angle X-ray spectroscopy)

By detecting characteristic X-rays excited during RHEED (reflection high energy electron diffraction) experiment, high sensitive measurement of the adsorbate is possible if the X-ray detector is put at the critical angle (θc) corresponding to the total reflection of the X-ray. Furthermore, measuring the glancing angle (θg) dependence, we can analyse the depth distribution of composition at surface. The resolution in depth direction is about 1 ML. Applying these methods to the study of epitaxy of metals (Ag, Au, Sn, Ga and In) on the Si(111)-n x m-M surface structures (metal induced Si(111) reconstructed surface structures), new growth modes were observed, such as substitution-atom growth mode, floating-atom growth mode and some complex growth modes. (author)