This is a physico-chemical etching because combines ionic bombardment, mechanical energy and a chemical reaction between ionized gas and sample surfaces. The gas atoms react with the sample ones to form new volatile species which will be evacuated by the pumping system. It is also known as a reactive ionic etching or also dry etching because it takes place within a plasma, contrary to wet etching. The different parameters adjustment (pressure, power, temperature and polarisation) enables to determine more or less the etching process choice. In fact, a low polarisation associated to high pressure and temperature favour the chemical process. On the opposite, a high polarisation voltage and a low pressure favour the mechanical bombardment. Isotropic and anisotropic etchings can be obtained: chemical reactions between gas and sample produce a selective and isotropic etching whereas the surface erosion, due to ionic bombardments, is anisotropic and non-selective (vertical sidewalls can be achieved by favouring mechanical etching due to ions and materials shocks). By choosing the reactive gas, fluorinated or chlorinated, several materials can be etched (see below).
In the institute, one of these machine is often used for plasma surface treatment: surface cleaning and functionalization in order to increase polymers adhesion.