THIN-FILM THICKNESS AND DENSITY DETERMINATION FROM X-RAY REFLECTIVITY DATA USING A CONVENTIONAL POWER DIFFRACTOMETER

The determination of thin-film thickness and density from X-ray specular and off-specular reflectivity data obtained using a conventional powder diffractometer has been investigated. An analysis of specular reflectivity data for a 565.9 angstrom Pt film showed that the results were determined precisely and agreed with those obtained previously from a high-resolution reflectometer. A systematic study of the effect of film-surface misalignment revealed that the values of thickness were insensitive to the alignment. A precision of about 1% or less was obtained from off-specular reflectivity data with a surface misalignment of 0.20-degrees or less, The insensitivity makes conventional powder diffractometers attractive for film thickness determination and opens this technique to many laboratories. The values of density were found to be relatively more sensitive to surface alignment. Nevertheless, densities with a precision of 3% and better were obtained when the film surfaces were aligned to within the effective divergence of the incident X-ray beam.