Wave fields in Si(111)layers under RHEED conditions

Wave fields under the condition of reflection high-energy electron diffraction have been calculated based on a dynamical theory of electron diffraction. In order to study the fundamental behavior of the wave field, calculations have been carried out for simple crystal models which consist of several atomic layers from a single monolayer to three bilayers of the bulk terminated Si(111) surface. Density maps of the wave fields in the model crystals are presented for various glancing angles. Relations between the wave fields and rocking curves are also discussed in detail. It is found under surface wave resonance conditions of internal emergence threshold that the wave field concentrates very intensely in the middle of the first bilayer. The calculated rocking curve of the specularly reflected beam has a very intense peak. It is demonstrated that examination of the wave field is useful in clarifying the origin of each peak in the rocking curve.