Surface functionnalization is a key step for the making of micro-devices such as MEMS or biochips. Control of localized surface energie properties is required in many applications like water management in micro-fuel cells or localization of chemical or biological substances. The aim of this work is to study the potential of plasma polymerization of a cyclic organosilicon compound to supply the various needs in surface functionnalization. Plasma polymerization kinetics and growth modes depend on critical process parameters. These parameters mainly govern the conformation of the plasma polymer which determines its bulk properties. These bulk properties influence the surface properties. Using the present process, low surface energy, 18 mJ·m−2, and high surface energy, 68 mJ·m−2, could be obtained depending on the synthesis conditions. The cyclic nature of the polymer conformation surprisingly control the wetting hysteresis properties of the surface with high accuracy when the process works in the oligomerization growth mode. Finally, the interest of such a process is illustrated with some examples of applications showing the potential of these materials, i.e. the cyclic plasma polydimethylsiloxanes.
Key-words: PECVD, Plasma, Plasma Polymerization, Organosilicon, Thin Films, Coatings, Surface Energy, FTIR, XPS, Ellipsometry, Wetting Hysteresis.
