The effect of nitrogen ion bombarding energy on the bonding structure of nitrogenated tetrahedral amorphous carbon film

Abstract

The tetrahedral amorphous carbon (ta-C) films with more than 80% sp3 in fraction are deposited by the filtered cathode vacuum arc technique. Then the energetic nitrogen (N) ions are used to bombard the ta-C films to fabricate nitrogenated tetrahedral amorphous carbon (ta-C:N) films. The composition and the structure of the films are analyzed by visible Raman spectrum and X-ray photoelectron spectroscopy. The result shows that the bombardment of energetic nitrogen ions can form CN bonds, convert CC bonds into C＝C bonds, and increase the size of sp2 cluster. The CN bonds are composed of C＝N bonds and CN bonds. The content of C＝N bonds increases with the N ion bombardment energy increasing, but the content of CN bonds is inversely proportional to the increase of nitrogen ion energy. In addition, CN bonds do not exist in the films.