Performance improvements of the hydrophobic and the dielectric properties of parylene C

The increase in the hydrophobicity at the same time as the reduction in the dielectric properties of an insulating material are the main factors necessary to improve the signal response of the electrowetting- on- dielectric and the organic field effect transistor electronic devices. Oxygen (O-2) and fluorine (CF4) plasma treatments on 3.7 mu m thicknesses-parylene C were carried out to understand the surface hydrophobicity character and their effect on the dielectric properties of the material. Fast hydrophobic recovery was observable during the first day after the O-2 treatment due to the reorientation of the polar polymer end chains to the bulk of parylene C. CF4 plasma treatments reveal a noticeably increase of the hydrophobicity as the treatment time increases. Energy dispersive X-ray and Fourier transform infrared analyses have confirmed an increase in the number of fluorine containing CFx bonds where 1 <= x <= 3 after fluorine plasma treatments and after aging. The PPX C film treated with CF4 plasma at 500W for 30 min indicated the best hydrophobic character and the best dielectric properties due to the highest loading fluorine content in our experimental conditions. (C) 2013 AIP Publishing LLC.