The effect of O2 on the quality of diamondlike films formed in a cathodic arc plasma deposition

Amorphous diamondlike films are deposited on Si wafer at temperature lower than 300°C in a cathodic arc plasma deposition (CAPD) system. Graphite plate with density 1.9 g/cm3 was employed as the cathode target and the carbon source. NdFeB magnets with 1000 G strength were installed behind the graphite target to steer the motion of arc spots on graphite. The arc current was selected as low as 55 A in order to minimize the emission of microparticles from graphite target. The arc spots observed were moving steadily on the graphite target with a speed of about 1.5 cm/s. O2Ar gas mixtures were introduced into CAPD system and the total pressure was controlled to be 10 mTorr. The effects of the addition of O2, the rf self-bias (VB) applied to Si wafer and the deposition temperature (TS) on the quality of diamondlike films were investigated. It is concluded that the addition of O2 is the key factor that contributed to the quality improvement of diamondlike films. The higher the partial pressure of O2, the more significant is the influence of VB and TS on the quality improvement of diamondlike films.