Al(111) nitridation below 473 K induced by supersonic N molecular beam as observed by synchrotron radiation photoemission spectroscopy

Teraoka, Yuden; Jinno, Muneaki*; Harries, J.; Yoshigoe, Akitaka 

Aluminum can not react with N gas around 473 K, we found the direct nitridation of Al(111) surface at 473 K by using supersonic N molecular beam. We analyzed the thin film by using synchrotron radiation photoemission spectroscopy. At the surface temperature of 473 K, clear uptake of N-1s spectrum was observed depending on the N dose at the incident N energy of 2.0 eV. The N1s photoemission intensity increased almost linearly with increasing N dose. When surface temperature was 373 K, clear uptake of N1s spectrum was also observed at the incident N energy of 2.0 eV. In the case of surface temperature of 300 K, the N-1s photoemission peak was not observed until the N dose of 1.010 molecules/cm. Such large temperature dependence may be attributed to the N atom diffusion into bulk aluminum from the topmost surface because N atoms were observed even in a depth of 1 nm by angle resolved photoemission measurements.