High rate low power microwave plasma CVD of carbon nitride films

A novel power efficient microwave plasma reactor with an electrode - antenna generated plasma was used for the Plasma Enhanced Chemical Vapor Deposition (PE CVD) of CNx films at different experimental parameters. Maximum film growth rates in the N-2 + C2H2 plasma reached several mu m/min at microwave powers of the order of 10 W. The geometry and properties of the plasma ball produced by the microwave antenna electrode were compared with the film growth rates on substrates positioned against the antenna. The radial profiles of the CNx firm thickness were found to be similar to the radial dependencies of the vibrational temperature of N-2 molecules, having about 400 K higher values at the shell of the plasma hall than in its axis. The plasma electron density, however, did not exhibit comparable shapes of radial profiles. Possible explanations of these effects and their consequences on the film growth are discussed.