Etching is an important step in the fabrication of semiconductor devices and other similar process. It includes wet etching, a solution based method, and drying etching, based on vacuum process typically.
The above table lists different etchants to etch different materials. Wet etching is an easy fast process with simple etching equipment; however it has several disadvantages including isotropic etching, leading to undercut and difficulty in making fine features, and others as shown in the following figures.
