In Plasma Surface Etching the material surface is been removed. Materials like Teflon needs to be etched in order to achieve higher surface energy. It is also called as dry etching as it uses no harsh chemicals. The timing for Plasma Etching will be higher when compared to Activation or Cleaning to see any noticeable effects. There are also 2 types of etching Anisotropic and Isotropic, depending upon the application and the electrode design any of them can be achieved. Since the etching rate in isotropic etching is constant in all directions, a material's attributes are unaffected by the direction. While anisotropic etching is direction-dependent, it eliminates material in a certain direction.
RIE - A technique for etching used in microfabrication is reactive-ion etching (RIE). RIE is a form of dry etching that differs from wet etching in its properties. To remove material that has been deposited on wafers or any other material's surface , RIE employs chemically reactive plasma. An electromagnetic field produces the plasma in a low-pressure (vacuum) environment. The surface is attacked by high-energy ions from the plasma, which react with it. A wafer platter is located in the bottom portion of a cylindrical vacuum chamber in a standard (parallel plate) RIE machine.
The PTFE is etched by placing it inside the chamber then the fluorine molecules from the fluoropolymer's carbon-fluorine backbone are removed by introducing hydrogen inside this chamber and as a result of the chemical reaction with the surface, leaving carbon atoms with insufficient electrons this carbon on the surface is reactive and hence that promote adhesion forms on the surface as a result of the restoration process. This is called as Dry Etching.