50 Years of Reactive Ion Etching in Microelectronics

In this short review, the evolution of plasma etching technologies used in microelectronics fabrication since the discovery of the reactive ion etching process 50 years ago is explored. These evolutions are first discussed from a process engineering point of view. After giving some examples of present and future challenges, it is described how the precision of the etching can be improved by using innovative solutions such as pulsing plasmas and cyclic processes. These changes are then discussed in a second section from a design point of view for industrial equipment and components. In particular, the tool design evolution is discussed by addressing its generic hardware components, most common plasma sources, power coupling efficiency and matching networks.