Microstructure and optical properties of SiCN thin films deposited by reactive magnetron sputtering

Abstract

Silicon carbonitride (SiCN) thin films were prepared by reactive magnetron sputtering of a sintered silicon carbide target in a mixture of argon (Ar), hydrogen and nitrogen (N2). The thicknesses of the films deposited with the N2/Ar flow ratios of 0.18 and 0.7 are 68 and 124nm respectively, and the elements Si, C, N are well-distributed in the films. The Si–Si, Si–C, Si=C, C–C, C–N and N–Si bonds are formed in the SiCN films, the increase of the N2/Ar flow ratio promotes the nitrogen incorporation into the films and the formation of Si–N bond, but suppresses the formation of C–C, C–Si and N–C bonds. The optical band gaps of the SiCN films deposited with N2/Ar flow ratios of 0.18 and 0.7 are 2.7 and 2.9eV respectively.