Study on the surface energy characteristics of polydimethylsiloxane (PDMS) films modified by C4F8/O2/Ar plasma treatment

We conducted plasma treatment on polydimethylsiloxane (PDMS) films using inductively coupled C4F8/O-2/Ar gas mixture plasma to modify their surface properties. We investigated the relationship between plasma characteristics and the changes in PDMS surfaces in order to understand the surface modification mechanism. The surface characteristics of PDMS films were evaluated in detail by surface energy measurements, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). Using contact angle measurements, it was confirmed that the surface, polar, and dispersive energies of the plasma-treated PDMS films increased as the O-2 gas ratio increased. AFM analysis showed that the roughness of plasma-treated PDMS surfaces increased when the O-2 gas ratio increased. XPS analysis confirmed the presence of a functional group CFx (X = 1, 2, and 3) in C4F8-rich plasma and a functional group O-H in O-2-rich plasma. It was confirmed that the surface energy of the PDMS films could be controlled by controlling the C4F8/O-2/Ar plasma treatment parameters which should be required for applying the direct transfer technique in each material having different surface energy. (c) 2017 Elsevier B.V. All rights reserved.