Epitaxial wafer

An epitaxial wafer (also called epi wafer, epi-wafer, or epiwafer) is a wafer of semiconducting material made by epitaxial growth (epitaxy) for use in electronics.

Silicon epi wafers were first developed around 1966, and achieved commercial acceptance by the early 1980s. Two methods of growing the epitaxial layer on existing silicon or other wafers are currently used: metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE). These wafers are sometimes newer types of semiconductors such as gallium nitride (GaN), or some combination of the elements gallium, indium, aluminum, nitrogen, phosphorus or arsenic.