Characterization of molecular nitrogen in III-V compound semiconductors by near-edge x-ray absorption fine structure and photoemission spectroscopies

Formation of molecular nitrogen under low-energy nitrogen bombardment of III-V compound semiconductor surfaces has been studied by photoemission spectroscopy around N 1s core-level and near-edge x-ray absorption fine structure (NEXAFS) around N K edge. Interstitial molecular nitrogen N2 has been formed in all of the samples under consideration. The presence of N2 produces a sharp resonance in low-resolution NEXAFS spectra, showing the characteristic vibrational fine structure in high-resolution measurements, and at the same time, a new peak, shifted toward higher binding energies for several eV, in all N 1s photoemission spectra.