It is reported for the first time that the periodical ripple surface feature at micrometer-scale was observed on hydrogenated amorphous carbon nitride films deposited by pulse plasma chemical vapor deposition (CVD) technique. Nitrogen incorporation to hydrogenated amorphous carbon films and the different growing environments of pulse dc plasma discharge perhaps played crucial role in the surface morphology transformation of hydrogenated amorphous carbon nitride films. (c) 2006 Elsevier B.V. All rights reserved.