Investigation of silicon carbon oxynitride thin film deposited by RF magnetron sputtering

Abstract

In this research, silicon carbon oxynitride (SiCON) thin films were deposited on silicon substrate by a radio frequency magnetron sputtering method. The effect of methane reactive gas flow rate on the structural, morphological, optical, and mechanical properties of the thin films was evaluated by using of grazing incidence X-ray diffraction (GIXRD), Raman spectroscopy, attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) , field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), fourier transform infrared spectroscopy (FTIR), ellipsometry and nano-indentation methods. The results of the GIXRD proved the formation of an amorphous structure in the thin films. Also, the Raman spectroscopy results determined the absence of graphite nanocrystals in the thin film structure. FE-SEM revealed the formation of a thin film with a smooth, dense and crack-free surface. AFM results showed that SiCON thin film is formed with very low surface roughness in the RMS range of 0.73 nm to 4.39 nm. The results of the ellipsometry analysis indicated that the refractive index of the thin film was changed during increase of the CH₄ reactive gas flow rate in the of 1.4 to 1.61 at 4 µm. According to the nano-indentation results, sample N10-C20-R1 has the highest hardness and Young's modulus equals 22.7 GPa and 231.6 GPa, respectively.