STUDY OF X-RAY REFLECTIVITY FROM SI FILM INTERFACE LAYER SI SUBSTRATE AND APPLICATION TO LOW-TEMPERATURE EPITAXIALLY GROWN SI/SI SUBSTRATE

An approximate equation for X-ray reflectivity from a Si film/interface layer/Si substrate with a smooth surface was derived analytically. The oscillation amplitude, corresponding to the Si film thickness, is modulated with a sine function due to the presence of the interface layer. The thickness and X-ray refractive index of the interface layer can be evaluated from the period of the sine function and the maximum value of the oscillation amplitude, respectively, when the reflectivity is expressed on a logarithmic scale. This method was applied to analysis of a defective Si film epitaxially grown on Si substrate. The oscillation structure was observed in the X-ray reflectivity and its amplitude was modulated with a sinelike function. This meant that there was a layered structure near the interface between the epitaxially grown Si film and Si substrate. The average thickness and density of the layer were evaluated from the reflectivity and were determined to be about 1.4 nm and 2.09 g/cm3, respectively.