Etching

Etch is a process that removes unwanted materials from the surface of a substrate by various dry and wet techniques. These techniques are used to remove silicon dioxide, silicon nitride, polysilicon, aluminum, tungsten, contamination particles, and other layer materials. This process step creates the layer definition that is based on the outcome of a previous photolithography process step. These etch processes transform a single layer of semiconductor material into the patterns, features, lines, and interconnects.