Plasma enhanced deposition of silicon carbonitride thin films and property characterization

Silicon carbonitride thin films were elaborated by reactive co-sputtering of graphite and silicon onto Si(111) substrates. The low-pressure electron cyclotron wave resonance (ECWR) plasma was radio-frequency biased both to sputter the target and to bombard the growing film at moderate energies (up to 180 eV). X-Ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and atomic force microscopy (AFM) were applied to characterize the deposits. While films grown with pure nitrogen are exclusively amorphous, nanocrystallites are observed in specimens deposited with N-2 + Ar mixture and the grain size can be well controlled. Depending on the processing parameters, the films displayed a variety of surface morphologies. The Vickers hardness for amorphous samples is roughly 17 GPa, slightly larger than the maximum value 13.8 GPa measured in crystalline specimens. (C) 2002 Elsevier Science B.V. All rights reserved.