Electron Probe Micro Analyzer (EPMA) uses the characteristic X-ray for analysis. Therefore the depth of analysis area is spread to a few micrometer. It is difficult to make the quantitative or state analysis of surface thin-film. However, it is possible to measure the thickness of thin-film by using the X-ray intensity ratio between the film and bulk standard specimen under an assumed X-ray depth distribution function. In this paper, a known composition thin-film was measured by EPMA and the result was applied to thin-film area analysis.
Film thickness was measured as mass thickness (ρz) by the intensity ratio of the characteristic X-ray intensities between the thin-film and bulk standard. As the X-ray distribution function ϕ(ρz) the model due to Packwood and Brown1) was used, which is written as.
An error is thought to exist in the thickness calculation because the backscattering yield near the interface is different when the difference in the atomic numbers is large between the thin-film and the substrate.