Raman studies on nanocomposite silicon carbonitride thin film deposited by r.f. magnetron sputtering at different substrate temperatures

Abstract

Raman studies of nanocomposite SiCN thin film by sputtering showed that with increase of substrate temperature from room temperature to 500 °C, a transition from mostly sp2 graphitic phase to sp3 carbon took place, which was observed from the variation of ID/IG ratio and the peak shifts. This process resulted in the growth of C3N4 and Si3N4 crystallites in the amorphous matrix, which led to increase in hardness (H) and modulus (E) obtained through nanoindentation. However, at a higher temperature of 600 °C, again an increase of sp2 C concentration in the film was observed but the H and E values showed a decrease due to increased growth of the graphitic carbon phase. The whole process got reflected in a modified four-stage Ferrari–Robertson model of Raman spectroscopy.