Compound semiconductor
From Wikipedia, the free encyclopedia
A Compound Semiconductor is composed of elements from two or more different groups of the Periodic Table, e.g. (1) Group III (B, Al, Ga, In) and Group V (N, P, As, Sb, Bi) for the compounds AlN, AlP, AlAs, GaN, GaP, GaAs, InP, InAs, InSb, AlInGaP, AlGaAs, InGaN etc, or (2) the compounds of Group II (Zn, Cd, Hg) and Group VI (O, S, Se, Te) such as ZnS, ZnSe, ZnTe, CdTe, HgTe, CdHgTe etc.
The range of possible formulae is quite broad because these elements can form binary (two elements, e.g. GaAs), ternary (three elements, e.g. InGaAs) and quaternary (four elements, e.g. InGaAsP).
Although Si and Ge are elemental semiconductors, it's worthwhile to note that some Si-based semiconductors that are formed by two elements from the same group (e.g. SiC and SiGe) are also termed as "Compound Semiconductor" in the literature. However, while SiC is a true compound, SiGe should be considered as an alloy.
Metalorganic Vapor Phase Epitaxy or MOVPE is the most popular deposition technology for the fomation of compound semiconducting thin films for devices. It uses ultrapure metalorganics and/or hydrides as precursors source materials in an ambient gas such as hydrogen.
Other techniques of choice are Molecular Beam Epitaxy (MBE), Hydride Vapour Phase Epitaxy (HVPE), Liquid Phase Epitaxy (LPE), Metalorganic Molecular Beam Epitaxy (MOMBE) and Atomic Layer Deposition (ALD), etc.
An introductory online resource for such semiconductors, "Britney's Guide to Semiconductor Physics", is also available as a reference for semiconductor scientists, non-scientists and Britney Spears fans.
