Argon gas dilution effect on the properties of amorphous carbon nitride thin films

Abstract

Optical and structural properties of amorphous carbon nitride (a-C:N x ) thin films deposited on p-type silicon (p-Si) and quartz substrates by microwave (MW) surface-wave plasma (SWP) chemical vapor deposition (CVD) at low temperature (< 100 °C) were analyzed in this paper. Argon (Ar: 100 sccm ∼ 300 sccm) was used as carrier gas while acetylene (C 2H 2: 5 sccm) and nitrogen (N: 5 sccm) were used as plasma source. Analytical methods such as X-ray photoelectron spectroscopy (XPS), FT-IR and UV–visible spectroscopy were employed to investigate the structural and optical properties of the a-C:N x thin films respectively. The optical gaps of the films were tailored from 1.7 eV to 2.2 eV. Lowest optical gap (1.7 eV) and highest deposition rate were obtained from the a-C:N x thin film prepared at 200 sccm Ar gas flow rate.