C–SiC–Si gradient films formed on silicon by ion beam assisted deposition at room temperature

Ion beam assisted deposition (IBAD) of carbon under medium energy (35 keV) Ar ion bombardment onto a silicon target results in the formation of silicon carbide. The formation of a-C–SiC–Si gradient films is dependent on the ion/atom arrival ratio (I/A). All films are deposited at room temperature. The gradient layers formed are examined for their composition using RBS. Depending on the I/A ratios, mixed interfaces of different widths, where silicon carbide exists, are formed. The SiC bonding in the mixed region is proven by XPS. The film formed on top of some samples contains amorphous carbon regions as shown by Raman spectroscopy. The surface of the layers grown is rather smooth with a roughness of several nanometres.