Nitridation of a diamond film using 300-700 eV N-2(+) ion beams

Diamond samples grown on Si substrates by chemical vapor deposition were ni trided at room temperature by irradiation of 300-700 eV N-2(+) ion beams. T he C ls and N ls XPS spectra were taken during nitridation and after anneal ing in ultrahigh vacuum. These spectra were tentatively divided into three components. The dominant part of the N Is spectrum split clearly into two c omponents of the binding energies of 398.6 and 400.8 eV after annealing. Th e N Is component at similar to 398.6 eV and the C is component at similar t o 287.8 eV are attributed to carbon nitrides such as CNx, for example, C,N, . The nitrogen atoms having N Is core level of similar to 401 eV have to be positively charged compared with similar to 400 eV of neutral nitrogen. Th ey donate electrons to the surface state and cause an upward band bending ( n-type semiconductor case), which induces the peak shift of the C ls XPS of the diamond toward a higher binding energy of similar to 285.6 eV. (C) 200 0 Elsevier Science S.A. All rights reserved.