Thickness measurement of low-Z films fabricated on thick substrate using EDXRF technique

Abstract

The present work reports a method for thickness measurements of low-Z films deposited on a thick substrate using energy dispersive X-ray fluorescence (EDXRF) technique. For this, ZnO and single-wall carbon nanotubes (SWCNTs) films (thickness ~ 1–100 mm) were fabricated on thick Si substrates using a sol-gel spin coating technique. The fabricated films were characterized using X-ray diffraction (XRD) and atomic force microscope (AFM) measurements. The thicknesses of fabricated films were determined from the measured attenuation of Si-Kαβ characteristics X-rays emitted from the thick Si substrate in coated materials. The thick substrate was excited by Mn Kα (5.895 keV) and Kβ (6.492 keV) X-rays obtained from annular 55Fe radioactive source in reflection mode geometrical setup. The emitted characteristics X-rays were detected by a low energy Ge (LEGe) detector coupled with PC based multichannel analyzer. The obtained results show good agreement with the values obtained from well-established X-ray fluorescence (XRF) and atomic force microscopy (AFM) measurements. The experimental results recommend the use of reported methodology for thickness measurement of low-Z materials deposited on a thick substrate for material characterization in future.