X-ray waveguide phenomenon in thin layers under grazing incidence conditions

Hayashi et al. published a paper on refracted x-rays propagating near the s urface under grazing incidence conditions. For pure silicon wafers the refr action can be described by Snell's law, whereas for thin n-C33H86 layers on silicon wafers an additional beam occurs. An interesting feature of this b eam is the constant photon energy over a wide range of take-off angles. The authors suggested that the layer acts as a waveguide and a suitable x-ray refraction theory for thin films is required. The present investigation dea ls with the interpretation of the waveguide phenomenon by the concept of an interference between two plane wave fields propagating under angles +/- ph i. The experimental results of Hayashi et al. are in good agreement with ou r calculated values. Copyright (C) 2001 John Wiley & Sons, Ltd.