Chemical structure and mechanical properties of Si-containing a-C:H and a-C thin films and their Cr- and W-containing derivatives

Hardness and elastic modulus of the a-C-Si-(O,N) films could be adjusted in a wide range of approx. 5-15 GPa and 40-140 GPa, respectively. Systematic alteration of these values with the composition (C/Si, O/Si and N/Si atomic ratio) and with the chemical structure (αSi) was established and their interrelations are discussed. Whilst incorporation of Cr does not alter the mechanical properties, the addition of W increases H and E up to 19 GPa and 210 GPa, respectively.