Effects of growth parameters on the yield and morphology of Si3N4 microcoils prepared by chemical vapor deposition

In this study, we provided a reliable chemical vapor deposition (CVD) method to synthesize high-purity Si3N4 microcoils in high yield without the presence of catalyst. The achieved products were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscope. The results indicated that the yield and morphology of Si3N4 products were influenced by the synthesis parameters such as reaction temperature, reaction time and gas flow rate. The particular conditions favorable to high yield synthesis of Si3N4 microcoils were obtained through a series of control experiments. Furthermore, the growth of Si3N4 microcoils was supposed to be in accord with vapor-solid (VS) growth process and the different growth rates between the amorphous layer and the crystalline layer were used to explain the formation of the coil geometry.