Effect of the nitrogen flow on the properties of Si-C-N amorphous thin films produced by magnetron sputtering

Анотація

The Si-C-N thin films have been deposited onto silicon substrates by reactive direct current magnetron sputtering of a silicon–carbon target at different ratios of nitrogen, F_N2, and argon, F_Ar, flows rates. The X-ray diffraction, IR spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy, and nanoindentation have been used to study the structure, picture of chemical bonds, surface morphology, and mechanical properties of the produced Si-C-N films. It has been found that all Si-C-N films produced are X-ray amorphous, their surface roughness slightly depends on F_N2 and is 0.23–0.28 nm; an increase of the F_N2 brings about the appearance and intensification of the Si-N and C-N bonds as well as weakening of Si-C bonds; thin films contain a small amount of oxygen, which makes Si-O and C-O bonds and the latter weaken with increasing F_N2. The nanohardness and elastic modulus of the SiC amorphous thin films have been defined to be 23 and 207 GPa, respectively. The nanohardness and elastic modulus of Si-C-N thin films decrease with increasing nitrogen flow, which is caused by the weakening of Si-C bonds.