Morphology and patterning processes of thin organosilicon and perfluorinated bi-layer plasma polymer films

An audio-frequency plasma polymerization setup with a planar plasma source was used to deposit thin bilayer plasma polymer films using heptadecafluoro-I-decene (HDFD) and hexamethyldisiloxane (HMDSO) as monomers. HDFD was used to deposit a thin Teflon-like plasma polymer film with low surface energy. HMDSO was used to coat this layer with a highly cross-linked SiCxOyHz film. The growth of the HMDSO plasma polymer illustrates the aspects of island formation at small film thickness (d < 10 nm) as a result of the low surface energy of the HDFD plasma polymer film surface and the buckling-induced patterning by the compressive C, stress of the HMDSO plasma polymer film at higher film thickness (d > 10 nm). The film thickness was controlled by quartz crystal microbalance (QCM) and spectroscopic ellipsometry. The chemical structure of the films was measured by means of FT-IR and XPS. The information about the surface morphology was provided by atomic force microscopy (AFM) measurements.