Abstract: Diamond-like carbon ( DLC ) films were prepared using the RF magnetron sputtering with high purity carbon targets and high purity methane as carbon sources under different RF power. The structure and properties of the films were studied by the scanning electron microscopy, Fourier transform infrared spectroscopy and micro-hardness tester. The results show that the films is dense and uniform. With increasing the RF power, the growth rate and the proportion of carbon atom in the film increase. The films prepared at 200 W have high sp³ content, and its molecular structure and properties are more towards to diamond. The Vickers hardness of the films reaches 1123.42 MPa, and it was found that the hardness of DLC films increases first and then decreases with the increasing RF power. The graphitization degree of the DLC film increased.

Key words: DLC film, RF magnetron sputtering, RF power, bonding structure, hardness