An excellent hydrophobic surface has a high contact angle over 147 degree and the contact anglehysteresis below 50 was produced by using roughness combined with hydrophobic PTFE coatings, which were alsoconfirmed to exhibit an extreme adhesion to glass substrate. To form the rough surface, the glass was etched byAr-plasma. A very thin PTFE film was coated on the plasma etched glass surface. Roughness factors before orafter PTFE coating on the plasma etched glass surface, based on Wensel``s model were calculated, which agreeswell with the dependence of the contact angle on the roughness factor is predicted by Wensel``s model. The PTFEfilms deposited on glass by using a conventional rf-magnetron sputtering. The glass substrates were etchedAr-plasma prior to the deposition of PTFE. Their hydrophobicities are investigated for application as a anti-foulingcoating layer on the screen of displays. It is found that the hydrophobicity of PTFE films mainly depends on thesputtering conditions, such as rf-power, Ar gas content introduced during deposition. These conditions are closelyrelated to the deposition rate or thickness of PTFE film. Thus, it is also found that the deposition rate or the filmthickness affects sensitively the geometrical morphology formed on surface of the rf-sputtered PTFE films. Inparticular, 1,950-nm-thick PTFE films deposited for 30 minute by rf-power 50 watt under Ar gas content of 20sccm shows a very excellent optical transmittance and a good anti-fouling property and a good durability.
