Process to remove material from a solid surface, usual caused by chemical reactions. However also processes using only physical effects are designated as etching processes (Physical Etching, Ion Etching).
Specific etching processes are:
- Cleaning of surfaces by removing Oxyd-layers or adhering layers.
- Changing surface structures for example because of optical reasons (creating mat surfaces) or to increase the effective surface due to its roughness for better bonding
- Creating geometrical structures by covering destinct ares of a surface before starting the etching process, so that the covered areas remain unaffected by the etching
Etching is executed in reactive liquid substances (wet method) or by Plasme Treatment (Plasma-Etching) with an appropriate Process Gas. Some examples for Plasma-Etching are Silicon, SiO2 und Si4N3 in microelektronic business, Metals coated by an Oxyde and plastic materials when sufficient bonding performance cannot be achieved by Plasma Activation (for example PTFE)