Continuous polycrystalline SiCN films with high nucleation density have been successfully deposited by using CH3NH2, as carbon source gas in an ECR-CVD reactor. Fom the kinetic point of view, using CH3NH2, as carbon source could provide more abundant active carbon species in the gas phase to enhance the carbon incorporation in the SiCN films. The compositions of the SiCN films analyzed from Rutherford Backscattering Spectroscopy showed that higher [CH3NH2,]/[SiH4] ratio led to higher carbon content in the films. Moreover, a lower carbon content was measured when the film was deposited at higher substrate temperature. The direct band gap of the aforementioned SiCN films determined using PzR is around 4.4 eV, indicating a wide band gap material for blue-UV optoelectronics.