Reactive Ion Etching

In a high frequency, low pressure plasma of a suitable gas, e.g. CF₄, reactive ions are generated and accelerated onto the etched layer. The reactive ions produce a volatile etching product by chemical reactions with the etched material. By variation of the plasma parameters pressure and rf-power anisotropic and isotropic etching characteristics can be adjusted.
 

Ion Beam Milling

A homogeneous ion beam is generated by a suitable ion beam source and directed onto the etched sample. The use of ions from an inert gas, e.g. Argon, results in a physical etching process. Ion beam milling can be used to pattern arbitrary layer systems, because there is no need for chemical reactions.