Thickness measurements of single and composite thin metal films using the X-ray fluorescence technique

Abstract

A high frequency quartz crystal microbalance was used to calibrate an X-ray fluorescence (XRF) system employing a 241Am exciter source of 40 mCi an. Si(Li) detector with a resolution of 230eV at 5.9 keV. The quartz crystal monitor was previously calibrated down to about 200 Å using an interferometer. The XRF system was then used to extend the measurements down to about 15 Å employing quartz crystal oscillator measurements for comparison. Single and composite thin film layers of copper and silver were prepared on thin mica substrates using the vacuum evaporation method. The data indicate the advantage of this technique for the accurate measurement of ultrathin film thicknesses with the possibility of detecting changes in material densities.