Thin silicon carbonitride films are perspective low-k materials

The multifunctional amorphous and nanocrystalline silicon carbonitride thin films were synthesized by RPECVD using the gas mixture of hexamethyldisilazane (HMDS) with ammonia and helium within temperature range 600–1073 K. IR spectroscopy, Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), ellipsometry, X-ray diffraction using synchrotron radiation (XRD-SR), scanning electron microscopy (SEM), high-resolution electron microscopy (HREM), selected area electron diffraction (SAED), atomic force microscopy (AFM), measurements of hardness by nanoindenter, electrophysical and spectrophotometry measurements were applied to study their physicochemical properties. The presence of chemical bonding among Si, N, and C elements in SiCxNy films was established. According to data of XRD-SR, HREM, and SAED, the formation of the solid substitution solution occurs, with lattice parameters close to those of the standard phase α-Si3N4 in which a part of silicon atoms is substituted by carbon atoms. The analysis of electrophysical, optical, and mechanical properties of these films indicates the possibility for applications as low-k materials with mechanical characteristics and transparent layers in wide region of spectra (400–2200 cm−1).