Thickness determination of anodic titanium oxide films by electron probe microanalysis

Abstract

Thin film thickness can be readily associated to the X-ray intensities emitted under electron bombardment. The aim of this work is to develop a method for measuring titanium oxide thicknesses in biomaterials from the X-ray spectra induced in a scanning electron microscope. The oxide layers studied were generated with different anodizing voltages applied in phosphoric and boric acid solution (H3PO4/H3BO3). The oxygen Kα intensity was registered for each sample and related to the corresponding thickness. In order to account for local material alterations, a recalibration is shown to be necessary; Rutherford backscattering spectroscopy was used at this stage. The method is useful for TiO2 thicknesses in the range of interest for dental and orthopedic implants (10–100 nm), and it could be extended to greater thicknesses by adequately selecting the electron beam energy.