Photoemission spectroscopic analysis with synchrotron radiation for direct nitridation of Al(111) by supersonic N molecular beams

Teraoka, Yuden; Harries, J.; Yoshigoe, Akitaka

no journal, , 

We have conducted the direct nitridation of Al(111) surface by the inert N molecular beam at 473 K at the surface chemistry experimental station of BL23SU in the SPring-8. The synchrotron radiation of 686.8 eV was used for Al-2p, N-1s and O-1s photoemission measurements. After wet cleaning processes, the Ar ion sputtering and 773 K anneal cycle was repeated to remove a native oxide layer. A low energy electron diffraction pattern of 11 was confirmed. The N molecules adsorbed dissociatively on the Al(111) surface when the translational energy of N molecules was larger than 1.8 eV. A nitrogen uptake curve could be measured and was confirmed to be almost linear with increasing N dose at 2.0 eV. It implies that a protective layer may not be formed on the topmost nitride surface. The nitrogen diffusion into bulk was actually confirmed in the depth profile analysis by angle-resolved photoemission spectroscopy in conjunction with a maximum entropy method.