Composition and crystal structure of carbon nitride films prepared by the electron cyclotron resonance plasma sputtering method

Carbon nitride films were prepared on a Si(100) substrate by an electron cyclotron resonance plasma sputtering method using a carbon target and a nitrogen atmosphere. The maximum value of the N/C ratio in the film deposited at a substrate bias potential of about -55 V 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 600 °C showed a crystalline structure with a 500 nm average grain diameter. The x-ray diffraction pattern of the film deposited at 600 °C and a substrate bias potential of -50 V indicates no amorphous phase in the film, which is composed of β- and α-C₃N₄ phases containing an unidentified C–N phase. © 1998 American Institute of Physics.