Polyamide 6 (PA 6) films are treated with helium(He)/CF4 plasma at atmospheric pressure. The samples are treated at different treatment times. The surface modification of the PA 6 films is evaluated by water contact angle, atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The etching rate is used to study the etching effect of He/CF4 plasma on the PA 6 films. The T-peel strengths of the control and plasma treated films are measured to show the surface adhesion properties of the films. As the treatment time increases, the etching rate decreases steadily, the contact angle decreases initially and then increases, while the T-peel strength increases first and then decreases. AFM analyses show that the surface roughness increases after the plasma treatment. XPS analyses reveal substantial incorporation of fluorine and/or oxygen atoms to the polymer chains on the film surfaces. (C) 2009 Elsevier B.V. All rights reserved.