Fabrication of oleophobic fluorocarbon film by 13.56 MHz CH2F2/Ar plasma chemical vapor deposition

In order to control of the surface properties to create the oleophobic fluorocarbon film, this study reported the influence of low pressure CH2F2/Ar plasma processing on oil repellent thin film growth. Difluoromethane (CH2F2)/argon (Ar) gas mixture was used to generate low pressure plasma with radio frequency power at 13.56 MHz for fabrication of oleophobic fluorocarbon coatings. The surface characteristics of the CH2F2/Ar plasma-deposited films were studied by static contact angle measurement (CA), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The effects of CH2F2/Ar plasma on the surface characteristics of the plasma-deposited films were investigated as a function of the CH2F2 content. The fluorocarbon coating prepared under optimized experimental parameters exhibited the glycerol contact angle greater than 140°, confirming the oleophobic property of the coating. XPS revealed that plasma-deposited films obtained contain mainly CH, CF, C―CFx, and CF2 species. In addition, AFM analysis shows that possible ion bombardment from CH2F2/Ar plasma can increase surface roughness. The combination of the low surface energy CFx species and the rough surface morphology successfully form the oleophobic CH2F2/Ar plasma-deposited film.