Inductively Coupled Plasma etching is an anisotropic dry-etching process where material is removed with the use of chemically reactive plasma under a low pressure (~1-100 mTorr). Typically the material removed is a thinfilm previously deposited on a wafer. The ICP-RIE uses two independent RF sources, one to strike plasma in a gas mixture and one to create a DC bias which extracts and accelerates ions and radicals from the plasma towards a sample surface. This gives indipendent control of ion density and energy. ICP RIE is a popular dry-etching technique because of its possibilty for high ecth rates, great selectivity and reduced ion bombardment.