Effects of Temperature on Microstructure and Tribological Performance of a-CNx Films Prepared by Pulsed Laser Deposition
a-CNx films were deposited onto silicon wafers at temperatures from RT up to 600 °C by using pulsed KrF excimer laser deposition. The composition, morphology and microstructure of the CNx films were characterized by X-ray photoelectron spectrum (XPS), scanning electron microscopy (SEM) and Raman spectrum. The tribological performance of the films was investigated using a ball-on-disk tribometer. With increasing the deposition temperature ranging from RT to 400 °C, the N content of films dropped from 36 at.% to 22 at.%, the ratio of N-sp3 C bonds, hardness and friction coefficient of the film decreased. Further increase of deposition temperature led to the lack of nitrogen and the increasing degree of order in ringed sp2 C=C bonds of the amorphous carbon film. The mechanical and tribological performances became worse. The film deposited at 300°C showed a low friction coefficient of 0.11 and a preferable wear resistance of 1.65×10–7 mm3 Nm–1 in humid air.
Alan K.T. Lau, J. Lu, Vijay K. Varadan, F.K. Chang, J.P. Tu and P.M. Lam
X.H. Zheng et al., "Effects of Temperature on Microstructure and Tribological Performance of a-CNx Films Prepared by Pulsed Laser Deposition", Advanced Materials Research, Vols. 47-50, pp. 549-553, 2008