Chemical and structural analysis of crystalline carbon nitride thin films prepared by electron cyclotron resonance plasma sputtering process

Abstract
Carbon nitride films were prepared on Si(100) substrate, which was at self-bias potential by an electron cyclotron resonance plasma sputtering method uses a carbon target and a nitrogen atmosphere. The maximum value of the N/C ratio for the film deposited at a substrate bias potential of about -50V and ambient temperature was 1.35, which is close to the stoichiometric composition of C₃N₄. The surface morphology observed with scanning electron microscopy of the film deposited at a substrate bias potential of -45V and 600°C showed a crystalline structure with an average grain size of about 500nm. The x-ray diffraction patterns of the films deposited at 700°C suggests that the films are composed of crystal phases that may be different from the predicted C₃N₄ phases and an unknown new C-N phase with a lattice space of 0.473nm.