Formation of electrically conductive nitrogen-doped amorphous hydrogenated carbon (diamond-like carbon) films by the supermagnetron plasma chemical vapor deposition method

Using a supermagnetron plasma apparatus, electrically conductive amorphous hydrogenated carbon (a-C:H) films were formed at wafer temperatures below 60 °C. CH4/N2 mixed gas was introduced into the discharge chamber and nitrogen-doped a-C:H films were formed on thermally oxidized Si wafers. A high electrical conductivity of 1.02×10−4 Ω cm−1 was obtained at a N2 concentration of 25%, a gas pressure of 50 mTorr, and a radio-frequency power of 600 W. Measured film growth rate and microhardness were 160 nm/min and 1650 kg/mm2, respectively. Nitrogen inclusion in a film was confirmed by secondary-ion-mass spectroscopy, and its atomic concentration was measured to be about 4×1022 atoms/cm3.