Carbon thin films are prepared from adamantane and dibromoadamantane by using a plasma-enhanced chemical vapor deposition method. Deposition rate for dibromoadamantane is approximately two times higher than that for pure adamantane. Infrared spectra of the films indicate that adamantane units are incorporated in the films, although higher electron temperature results in disorder in the films. The films prepared from dibromoadamantane have higher thermal stability, higher hardness and Young modulus than those from pure adamantane. Permittivity (=3-4) of the dibromoadamantane films is higher than that (=2-3) of pure adamantame films, which is regarded as a result of incorporation of bromine atoms and C=C bonds having higher polarizability according to the structural analysis of the films. Possible solution methods are proposed for reducing inclusion of such unfavorable chemical species and chemical bonds. (C) 2009 Elsevier B.V. All rights reserved.