An etching process in vapor phase by the physical and/or chemical
reaction of the reactive gas or reactive plasma.
Basically, a reactive gas generated by electrical energy reacts with the
substrate and removes the material to form the desired shape or dimension.
Etching methods are divided into plasma etching, which is an isotropic
etching based on a chemical reaction, and ion etching, which is a directional
etching that uses a physical reaction (sputtering). Dry etching, which
uses one of these or both together, is extensively used in current LSI