Deposition of DLC:H films by C-sputtering assisted CH

Hydrogenated diamond-like carbon (DLC:H) films were deposited on Si substrates by a methane (CH4)-argon (Ar) plasma enhanced chemical vapor deposition (PE-CVD) technique assisted by carbon (C) sputtering. The deposition rates of DLC:H films increased with increasing Ar gas flow rate under a CH4 gas flow rate, and saturated at large Ar gas flow rates. The dielectric constants varied from 2.2 ε0 on DLC:H films deposited without Ar gas flow to 6.3 ε0 on DLC:H films deposited with large Ar gas flow. The C – V curve for the sweep of bias voltages from positive to negative was positioned above that of the return sweep of bias voltages from negative to positive because electrons are injected from Si substrates to the surfaces of DLC:H films. The C – V curve on the returning bias voltage sweep approached that of the going bias voltage sweep accompanying to an increase in dielectric constant