THIN FILM DENSITY DETERMINATION BY MULTIPLE RADIATION ENERGY DISPERSIVE X-RAY REFLECTIVITY

X-Ray Reflectivity provides a non-destructive technique for measuring density in thin films. A conventional laboratory, Bragg-Brentano-geometry diffractometer was employed to show the generalized feasibility of this technique. X-ray tubes with Cr, Cu and MO targets were used to provide a large overlap of energies for density fitting. X-Ray tube alignment and sample alignment were explored to find a self-consistent measurement technique. The real and complex indices for Ta, for Tao,, and for porous SiO2, also known as “xerogel”, were calculated and used in a reflectivity fitting routine. The density results from multiple energies provided a selfchecking method for true density extrapolation from misaligned samples. Density results for the xerogel films were compared with measurements by Rutherford backscattering spectrometry and by optical ellipsometry and showed consistency within errors.