Treatment of nanocrystalline diamond films by nitrogen implantation using PIII processing

The influence of N2 Plasma Immersion Ion Implantation (PIII) on undoped nanocrystalline diamond (NCD) films grown on silicon substrate by CVD process using a hot filament reactor was systematically studied. Before and after the implantation, NCD films were investigated using scanning electron microscopy (SEM), high resolution X-ray diffraction (HRXRD) and Raman scattering spectroscopy. Significant changes in the film surface morphologies due to the plasma implantation treatment were observed. The NCD morphology changed from “cauliflower-like” to a smoother surface after the nitrogen-plasma immersion. The Raman spectra are similar for the three kind of electrodes before and after PIII of 15 and 30 min. Although a small difference among the ratios concerning the D and G Raman band intensities (ID/IG) may be observed that seems to increase after the plasma treatment, associated to the disorder increase caused by nitrogen incorporation in the sp2 phase. Electrochemical response also showed that implanted NCD films had their electrical conductivity improved while the electron transfer kinetics decreased for such NCD films after 15 and 30 min of N2 implantation.