Tribological properties of a-C : N and a-C films prepared by shielded arc ion plating

Amorphous carbon nitride (a-C:N) and amorphous carbon (a-C) thin films that rarely contained hydrogen were synthesized on Si(100) wafers by means of s hielded are ion plating. Nanomechanical properties of these films were stud ied in relation to substrate bias voltage. The a-C film prepared at a DC bi as voltage of 100 V showed a maximal hardness of 35 GPa, whereas the film d eposited at - 500 V had a minimal hardness of 7 GPa. Wear resistance was ex cellent for films with hardness greater than 20 GPa when rubbed with a diam ond tip at a contact force of 20 muN. Hardness of the a-C : N films, remain ed in the range of 10-14 GPa, independent of the bias voltage. However, the wear resistance of the a-C :N films was much better than that of the hard a-C films. In particular, the a-C : N film prepared at - 300 V was so wear resistant that the film did not wear at all. (C) 2000 Elsevier Science Ltd. All rights reserved.