Effect of plasma treatment of PTFE substrates on the adhesion characteristics of vacuum-deposited Au films

PTFE foils were plasma-treated in order to enhance their adhesion to thin films. The effect of plasma treatment using argon and oxygen discharge gases on the surface energy of PTFE foils was examined by measuring the contact angles of water droplets placed on the foil surface. Exposure to the plasma for only about 10-20 s was very effective in enhancing the surface energy. By depositing gold films onto the PTFE substrates, it was found that this enhancement in surface energy was directly related to an increase in the film adhesion. It was also found that Ar plasma treatment of a few tens of seconds followed by O2 plasma treatment for 10 s was even more effective for adhesion enhancement.