DEPOSITION TEMPERATURE-DEPENDENT CHARACTERISTICS OF MAGNETRON-SPUTTERED CHROMIUM NITRIDE FILMS

Chromium nitride layers with CrN and Cr2N stoichiometry were deposited onto silicon substrates by means of reactive RF-magnetron sputtering at different substrate temperatures (300-830 K). The layer thicknesses were 100 to 1500 nm. Composition, surface roughness, grain size, microstructure and phase formation were analysed using ass (Rutherford backscattering spectrometry), RNRA (resonant nuclear reaction analysis), PAC (perturbed angular correlation), STM (scanning tunnelling microscopy) and XRD (x-ray diffraction). ass and RNRA depth profiling of the samples revealed for both nitrides homogeneous Cr and N concentrations over the whole layer depth. For Cr2N films, indications of a phase transformation due to the increased target temperature from a disordered Cr/N phase to the ordered Cr2N phase were obtained via XRD and PAC. The lateral grain size measured with STM and the vertical grain size measured with XRD are approximately the same for both nitrides at all deposition temperatures.