XPS and FTIR analysis of nitrogen incorporation in CNx thin films

CNx thin films have been deposited on Si(100) substrates using a new hybrid deposition system. This system combines excimer laser ablation of a graphite target and an atomic nitrogen source from a remote surface wave plasma. The films were characterized using X-ray photoelectron spectroscopy (XPS), elastic recoil detection (ERD) and Fourier transform infrared spectroscopy (FTIR). We found that the atomic nitrogen source enhances the incorporation of N in the CNx layers, for example, from N/C = 0.04 (plasma off) to 0.18 (plasma on). In addition, as nitrogen pressure in the deposition chamber is increased from 2 mTorr to 1 Torr, the N/C ratio increases from 0.18 to 0.56. The XPS and FTIR spectra indicate that at deposition pressures above 100 mTorr, nitrogen incorporation is enhanced through the formation of hydrogenated carbon nitride groups, while at lower pressures, only simple and double CN bands are detected. (C) 1998 Elsevier Science S.A.