Non-destructive depth profiling of Au/Si(100) with X-ray absorption spectroscopy

Yamamoto, Hiroyuki; Nojima, Takehiro; Esaka, Fumitaka  

In the present study, we examined to perform depth profiling with X-ray absorption spectroscopy (XAS) by changing electron energies (5-50 eV) for detection in order to develop non-destructive depth profiling method with chemical state information. Gold thin films (1-10 nm) deposited on Si(100) were used for specimens. The Si/Au ratios were calculated from the peak heights of each edge using observed XAS spectra. Obvious correlation between the Si/Au ratio and the electron energy is observed. With decreasing electron energy, the ratio increased significantly. This means that by reducing electron energy, information on deeper region of the surface can be obtained. These results indicate that by changing electron energies for detection, it is possible to perform non-destructive depth profiling in XAS analysis.