Alternative Plasma etching - PTFE Plasma etching, as the name implies, is a technique of etching in which plasma is used as an etchant instead of strong acids. Plasma is the fourth state of matter, formed by ionizing gas particles, through radio frequency or heating. In order to understand the process of plasma etching, it is important to understand the working of a plasma etching system. The system consists of two symmetrical electrodes for the generation of radio frequency and a ground electrode on which the sample to be etched is placed. There is a gas inlet through which etchant enters the system and there is an outlet for plasma. As the gas enters the system, voltage is applied to partially ionize gas particles.