Quantitative Analysis of (Y2O3)x (ZrO2)1-x Films on Silicon by EPMA

Abstract

Approximately 70 nm thick films of non-conducting (Y2O3)x(ZrO2)1-x (x ≈ 0.1) were deposited on Si(100) substrates by electron beam evaporation. Subsequently, electron probe microanalysis (EPMA) was applied to determine the yttrium content. Experimental efforts were made to assess the accuracy of the EPMA results and to determine the detection limits of the technique. The intensities of the characteristic X-ray lines Y Lα, O Kα, Zr Lα and Si Kα, emitted from the electron-beam excited samples, were measured with a Jeol JXA-50 A microanalyzer for beam energies of 4, 7, 10, 14 and 20 keV. Charging of the films did not occur. The intensities were calibrated with corresponding intensities of Y3 Fe5 O12 , Zr and Si standard samples. The number of Y, Zr and O atoms per cm2 were determined independently for each beam energy by comparing the measured intensities with calculations of a Monte Carlo simulation program. The number of atoms per cm2 were determined with an accuracy better than 5% and the uncertainties of the Y contents were below 0.25 atomic percent. The detection limits of the Jeol JXA-50 A for Y, Zr and O on a silicon substrate were 2.3, 4 and 13· 1014 atoms per cm2, respectively, at 200 nA beam current and 1 min counting time.