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Research was conducted to study nitrogen retention and release during implantation of hard amorphous carbon films with 20 keV N+ ions. Graphic cultures were determined in samples implanted up to saturation at 400 degrees C while structural modification processes were treated as a tendency towards thermodynamic equilibrium. Results showed that implantation led to the formation of a structurally modified C:N sublayer with a thickness similar to the ion penetration depth.

Wavelet decompositions of Raman spectra were investigated with respect to their usability for spike removal and denoising of the raw data. It could be shown that those operations should be performed sequentially. Suppression of spikes is not straightforwardly possible by wavelet transformation; however, the wavelet transform may be used to recognize the spikes by their first level detail coefficients. Spike locations could be projected from the details to the approximations and, further, to appropriate locations of the original spectrum. After spike recognition, those regions will be replaced by interpolated values. To complete processing, denoising is performed with the despiked spectrum by repeated application of wavelet transform methods.