The structure of a chemical-vapor-deposited (CVD) diamond thin film on a Mo substrate was studied using quasi-parallel X-ray and glancing incidence techniques. Conventional X-ray diffraction analysis revealed that the sample consists of a diamond thin film, a Mo2C transition layer, and Mo substrate. The Mo2C transition layer was formed by a chemical reaction between the diamond film and the Mo substrate during the CVD process. A method for layer-thickness determination of the thin film and the transition layer was developed. This method was based on a relationship between X-ray diffraction intensities from the transition layer or its substrate and a function of grazing incidence angles. Results of glancing incidence X-ray diffraction analysis showed that thicknesses of the diamond thin film and the Mo2C transition layer were determined successfully with high precision.
