Thin Solid Films, Vol.518, No.13, 3570-3574, 2010
Deposition of hydrophobic nano-coatings with low-pressure radio frequency CH2F2/Ar plasma processing
In an attempt to perform hydrophobic nano-coating, this investigation examined various operational parameters including in RF plasma power, system gas pressure, and CH2F2:Ar ratio of low-pressure plasma processing. The low-pressure plasma, generated with radio frequency power at 13.56 MHz, was fed difluoromethane (CH2F2)/Ar gas mixture. The surface characteristics of the plasma polymerized films were studied by static contact angle measurement (CA) and atomic force microscopy (AFM). As a result, increasing deposition of CH2F2 plasma polymerized films was achieved in enhanced RF plasma power input. The CH2F2 plasma polymerized films also were conducted in a varying system gas pressure with enhanced hydrophobic surface property. The effects of CH2F2/Ar plasma on the surface characteristics of the plasma polymerized films were investigated as a function of the Ar content. The super hydrophobic coating under optimized operational parameters prepared in this study obtained water contact angles greater than 150 degrees. It was found that the maximum water contact angles (161 degrees) was obtained at 1.5:1 (CH2F2: Ar) ratio. In addition, AFM analysis shows that possible ion bombardment from CH2F2/Ar plasma can increase surface roughness, and effectively form a hydrophobic coating on the surface of heat sensitive materials. (C) 2009 Elsevier B.V. All rights reserved.