Elemental X-ray images obtained by grazing-exit electron probe microanalysis (GE-EPMA)

A new method, grazing-exit electron probe microanalysis (GE-EPMA), was studied. Only X-rays emitted from the near-surface layer are measured at grazing-exit angles (e.g. <0.5°), whereas, with conventional EPMA, X-rays emitted from deep positions are also measured. Therefore, X-ray spectra with low background are obtained by GE-EPMA. Here, elemental mapping by GE-EPMA is shown for the first time. It was found that surface-sensitive elemental X-ray images were obtained for a thin Au film deposited on a Si wafer. The problems that occur at boundaries of different heights are discussed. Furthermore, it was difficult to recognize elemental distributions of Si, S, Ca, Na and Fe for aerosols deposited on a Si wafer in noisy X-ray images when using conventional EPMA; however, clear X-ray images were obtained under grazing-exit conditions.