Formation of carbon nitride films on Si(100) substrates by electron cyclotron resonance plasma assisted vapor deposition

Abstract

We report the growth of thin carbon nitride films on Si(100) substrates at temperatures in the range of 100–700 °C using electron-beam evaporation of graphite assisted with electron cyclotron resonance (ECR) plasma generated nitrogen species. The effect of the substrate temperature, and the nitrogen flow on the composition ratio C/N, and the C—N bonding were investigated using Fourier transform infrared spectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS), Rutherford backscattering spectroscopy (RBS), and Raman spectroscopy. The FTIR spectra show that the films produced exhibit a very high visible to infrared transmittance (0.85–0.95). These spectra were dominated by amine group (NH2) with the presence of C-N stretching modes. From both RBS and XPS, the nitrogen concentration in the film was calculated and was found in the range of 24%–48%, depending on the nitrogen partial pressure in the ECR source. Raman spectrum of the high nitrogen content thin film shows a well resolved peak at 1275 cm−1 suggesting the formation of a fourfold coordinated (sp3) CN film.