Dry etching

Classical etching processes are based on the material removal of surfaces by liquids (etching agents, primers), which attack the surface material (substrate). Depending on the substrate, these are solvents, alkalis or acids. These etching processes are referred to as wet chemical etching processes. Most substrates can only be etched with etching agents that are very harmful to the environment and health. Etching processes in the low-pressure plasma do not use any wet chemicals. This is way the etching processes in theplasmaare referred to as ‘dry etching’. Generally, any type of substrate can be treated by dry etching. The term ‘dry etching’ refers to the etching processes

• "plasma etching" ("chemical dry etching”, "isotropic dry etching")
• ion etching ("sputter etching", "micro-sandblasting", "physical etching")
• Reaktives Ionenätzen ("Reactive Ion Etching", "RIE").

Thus, the term “dry etching” describes all etching processes which can be realized using the plasma effect; the term “plasma etching”, on the other hand, only refers to etching via the chemical effect of theprocess gases. To avoid any confusion, it is advisable to use the term “chemical dry etching” instead of “plasma etching”.