Mechanical and optical properties of plasma-polymerized vinyltriethoxysilane

Plasma-polymerized films of vinyltriethoxysilane were deposited by plasma-enhanced chemical vapor deposition using an RF (13.56 MHz) helical coupling plasma system operated in pulsed regime. An effective power was reduced using pulsed plasma in order to decrease the degree of cross-linking of plasma polymer, which resulted in a material of lower Young’s modulus. The Youngʹs modulus and hardness of films increased for an enlarging effective power from 5.6 GPa (0.05 W) to 13.7 GPa (25 W) and from 0.8 to 1.7 GPa, respectively, if the time, when plasma is switched on, was fixed at 1 ms. The refractive index at a wavelength of 633 nm increased from 1.47 to 1.58 for those deposition conditions. Enlarging period the elastic modulus decreased for a constant power used.