CN molecular negative-ion beam deposition and ion energy dependence of atomic bonds between carbon and nitrogen in the films

The atomic bonds in carbon nitride films prepared by CN molecular negative-ion beam deposition were investigated with respect to the dependence on the incident ion energy. Mass-separated CN negative ions were deposited on n-Si(1 0 0) at a low ion energy in a gas pressure of 5.0x10-5 Pa. Raman spectra showed a broad Raman band similar to that of diamond-like carbon and a small band corresponding to C=N triple bonds near 2220 cm-1. The maximum nitrogen content was obtained at an ion energy of 75 eV, where the N/C ratio was 0.6, as found from RBS analysis. Detailed XPS spectra of N1s were measured to investigate inter-atomic bonds between C and N. The amount of C-N single bonds was increased with an increase in ion energy up to 75 eV. The amount of C-C single bonds showed a similar dependence upon the ion energy as the C-N single bonds