Preparation of amorphous carbon nitride films from toluene and nitrogen by rf-PECVD

Carbon nitride (CN_x) films were prepared by radio frequency plasma enhanced chemical vapour deposition (rf-PECVD) from nitrogen gas and toluene vapour onto Si(100) substrates. The films were characterised by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectrometry (FT-IR). XRD measurements suggested that the films have an amorphous structure. Toluene was reduced by rf plasma of 180 W. The CN_x films prepared contain very little hydrogen and hydrocarbon. It is found that increases in nitrogen gas pressure and rf-power levels lead to an increase in the nitrogen content in the deposited films. The maximum value of nitrogen content x = N/C is approximately 0.3 with rf-power of 180 W, toluene vapour pressure of 10 Pa, and nitrogen gas pressure of 40 Pa.