The effect of process parameters on the chemical structure of pulsed laser deposited carbon nitride films

Results of a comparative XTS study on 26 carbon nitride samples of different chemical composition fabricated by ablating a graphite target with an ArF excimer laser in N-2 atmosphere while systematically varying the pressure in the 1-100-Pa and the laser fluence in the 1.0-10-J cm(-2) domains are reported. N1s core level spectra recorded on all samples are consistently fitted by four components at 398.2, 399.4, 400.7 and 402.1 eV, respectively. Changes in the relative abundance of the individual spectral components of the N1s lines as a function of laser fluence and nitrogen pressure are interpreted in terms of changes in the chemical environment around nitrogen atoms. When present in low concentration, nitrogen atoms prefer sites allowing pyramidal configuration. With increasing concentration more and more atoms form C-N=C type bonds, nevertheless, in all films the majority of the nitrogen atoms occupies pyramidal configurations. (C) 2002 Elsevier Science B.V. All rights reserved.