Influence of silicon on the physical properties of diamond-like films

The effect of the inclusion of silicon atoms in the network of diamond-like carbon (amorphous carbon and hydrogenated amorphous carbon) is studied. Samples of amorphous hydrogenated CSi are deposited by means of a sputter-assisted plasma chemical vapour deposition system in which a carbon target is sputtered in an atmosphere composed of silane-diluted argon, where the silane flow rate is varied. It is shown that initially the effect of silicon inclusion is to reduce the size of the graphitic-like islands. When the amount of silicon is increased over a critical value, the network assumes the characteristic of the semiconductor-type amorphous hydrogenated SiC, where the properties of silicon are predominant.