The influences that both electron energy and density of a plasma bear on thin film formation are examined in the case of iodine-doped polyaniline polymerization. The plasma was produced by means of 13.5-MHz radiofrequency-generated glow discharges in low-pressure (ca. 10(-2) mbar) air between electrodes. Four representative inner regions of the reactor were selected according to the electron incidence. Given the uneven energy distribution found on the inside of this kind of reactors, variations in the polymer structure formed in the presence of iodine were found and studied by elemental analysis, thermogravimetry, infrared spectroscopy, and X-ray diffraction. The results indicate that the electric conductivity of polyaniline by plasma is a function of the iodine content and that such content is a function of the combined conditions of both reactor and plasma. (C) 2000 John Wiley & Sons, Inc.