Ion-beam-assisted deposition of CNx films

Carbon nitride thin films were prepared by the electron-gun evaporation of high purity carbon under concurrent bombardment with nitrogen ion-beam. The base vacuum reached 10(-4) Pa and the operating vacuum pressure was approximately 10(-2) Pa. The purity of the nitrogen gas was 99.99% and the ion-beam energy was 500-1000 eV. It was found that the deposition rate decreased with increase of the ion beam energy. The films deposited at different conditions were studied by X-ray photoelectron spectroscopy (XPS) and energy dispersive X-rays (EDX). The XPS data showed that C-N sp(2) and C-N sp(3) bonds existed in the films. The result with the maximum NIC atomic ratio of 0.43 was obtained from EDX measurements. The films tested by nano indentation had the maximum knoop hardness value of 23 GPa. The experiments of atomic oxygen action and cold welding in an ultra high vacuum environment proved that the films had good anti-atomic oxygen and anti-cold welding properties, and would have broad application prospects in space environments. (C) 2001 Elsevier Science B.V. All rights reserved.