Paper PS2-ThA10
Tunable Properties of Plasma-Polymerized Organosilicones

Thursday, October 23, 2008, 5:00 pm, Room 306

Plasma-polymerized organosilicones constitute a class of materials with a rich and varied scientific background. This class of materials possesses a special characteristic, which distinguishes it from other plasma polymers – the ability to vary and control the degree of its organic/inorganic character (i.e., the carbon content) by the appropriate choice of fabrication variables. This allows one to control many physicochemical properties over wide ranges resulting in an extraordinary potential for useful applications, which are only now beginning to be tapped. The organosilicon plasma polymers are widely recognized for their potential not only in optical and electronic applications, but also in composites and nanocomposites with controlled interphase. Plasma-enhanced chemical vapor deposition (PECVD) was used to prepare thin films of tetravinylsilane in a mixture with oxygen gas employing an RF (13.56 MHz) helical coupling pulsed-plasma system. Plasma polymer films of the thickness from 0.02 to 1 µm were deposited on silicon substrates at different powers (0.1 – 10 W) and oxygen content (0 – 79%) in mixture. When an appropriate on-time and off-time is selected for pulsed plasma, the physical and chemical properties of hydrogenated amorphous carbon-silicon oxide alloy (a-SiOC:H) may be controlled by the effective power. We will demonstrate that the mechanical properties (Young’s modulus 9 – 24 GPa, hardness 0.9 – 4.1 GPa), optical properties (refractive index 1.58 – 1.68 (633 nm), extinction coefficient 0.05 – 0.19 (250 nm), band gap 1.9 – 2.9 eV), and wettability (water contact angle 50 – 83 deg, surface free energy 35 – 58 mJ/m²) of the film may be well tuned in correlation with chemical properties (elemental composition, organic/inorganic character C/Si = 2.5 – 8.6, chemical structure) to prepare tailored materials not only for functional interlayer in polymer composites. The construction of multilayers from individual films of tunable properties will be discussed as well.