Dry etching (patterning) is a non-contact processing technology that chemically and physically removes material from a surface using plasma and reactive gases to form desired fine external shapes. It is an indispensable foundational technology for high-precision patterning on the sub-micron order in the manufacturing of micro-components such as semiconductors, MEMS, and LEDs. Anisotropic etching enables the realization of vertical sidewalls and high aspect ratio structures with high reproducibility. Representative methods include RIE, ICP-RIE, and DRIE. These methods cause less physical stress to the material and are suitable for processing thin films and brittle materials. As a clean process, it significantly contributes to improving the functionality of precision devices.