Aluminium gallium arsenide (AlxGa1−xAs) is a semiconductor material with very nearly the same lattice constant as GaAs, but a larger bandgap. The x in the formula above is a number between 0 and 1 - this indicates an arbitrary alloy between GaAs and AlAs.
Gallium arsenide (GaAs) is a III-V direct band gap semiconductor with a zinc blende crystal structure.
Gallium nitride is a binary III/V direct bandgap semiconductor commonly used in blue light-emitting diodes since the 1990s. The compound is a very hard material that has a Wurtzite crystal structure. Its wide band gap of 3.4 eV affords it special properties for applications in optoelectronic, high-power and high-frequency devices. For example, GaN is the substrate which makes violet (405 nm) laser diodes possible, without requiring nonlinear optical frequency-doubling.
Trimethylaluminium is one of the simplest examples of an organoaluminium compound. Despite its name it has the formula Al2(CH3)6 (abbreviated as Al2Me6 or TMA), as it exists as a dimer. This colorless liquid is pyrophoric. It is an industrially important compound, closely related to triethylaluminium.
Metalorganic vapour-phase epitaxy (MOVPE), also known as organometallic vapour-phase epitaxy (OMVPE) or metalorganic chemical vapour deposition (MOCVD), is a chemical vapour deposition method used to produce single- or polycrystalline thin films. It is a process for growing crystalline layers to create complex semiconductor multilayer structures. In contrast to molecular-beam epitaxy (MBE), the growth of crystals is by chemical reaction and not physical deposition. This takes place not in vacuum, but from the gas phase at moderate pressures. As such, this technique is preferred for the formation of devices incorporating thermodynamically metastable alloys, and it has become a major process in the manufacture of optoelectronics, such as Light-emitting diodes, its most widespread application. It was first demonstrated in 1967 at North American Aviation Autonetics Division in Anaheim CA by Harold M. Manasevit.
Aluminium gallium indium phosphide is a semiconductor material that provides a platform for the development of multi-junction photovoltaics and optoelectronic devices. It spans a direct bandgap ranging from ultraviolet to infrared photon energies.
Aluminium gallium nitride (AlGaN) is a semiconductor material. It is any alloy of aluminium nitride and gallium nitride.
Chemical beam epitaxy (CBE) forms an important class of deposition techniques for semiconductor layer systems, especially III-V semiconductor systems. This form of epitaxial growth is performed in an ultrahigh vacuum system. The reactants are in the form of molecular beams of reactive gases, typically as the hydride or a metalorganic. The term CBE is often used interchangeably with metal-organic molecular beam epitaxy (MOMBE). The nomenclature does differentiate between the two processes, however. When used in the strictest sense, CBE refers to the technique in which both components are obtained from gaseous sources, while MOMBE refers to the technique in which the group III component is obtained from a gaseous source and the group V component from a solid source.
Indium(III) chloride is the chemical compound with the formula InCl3 which forms a tetrahydrate. This salt is a white, flaky solid with applications in organic synthesis as a Lewis acid. It is also the most available soluble derivative of indium. This is one of three known indium chlorides.
Gallium(III) oxide is an inorganic compound and ultra-wide-bandgap semiconductor with the formula Ga2O3. It is actively studied for applications in power electronics, phosphors, and gas sensing. The compound has several polymorphs, of which the monoclinic β-phase is the most stable. The β-phase’s bandgap of 4.7–4.9 eV and large-area, native substrates make it a promising competitor to GaN and SiC-based power electronics applications and solar-blind UV photodetectors. The orthorhombic ĸ-Ga2O3 is the second most stable polymorph. The ĸ-phase has shown instability of subsurface doping density under thermal exposure. Ga2O3 exhibits reduced thermal conductivity and electron mobility by an order of magnitude compared to GaN and SiC, but is predicted to be significantly more cost-effective due to being the only wide-bandgap material capable of being grown from melt. β-Ga2O3 is thought to be radiation-hard, which makes it promising for military and space applications.
Isobutylgermane (IBGe, Chemical formula: (CH3)2CHCH2GeH3, is an organogermanium compound. It is a colourless, volatile liquid that is used in MOVPE (Metalorganic Vapor Phase Epitaxy) as an alternative to germane. IBGe is used in the deposition of Ge films and Ge-containing thin semiconductor films such as SiGe in strained silicon application, and GeSbTe in NAND Flash applications.
Trimethylindium, often abbreviated to TMI or TMIn, is the organoindium compound with the formula In(CH3)3. It is a colorless, pyrophoric solid. Unlike trimethylaluminium, but akin to trimethylgallium, TMI is monomeric.
Trimethylgallium, often abbreviated to TMG or TMGa, is the organogallium compound with the formula Ga(CH3)3. It is a colorless, pyrophoric liquid. Unlike trimethylaluminium, TMG adopts a monomeric structure. When examined in detail, the monomeric units are clearly linked by multiple weak Ga---C interactions, reminiscent of the situation for trimethylindium.
Indium gallium aluminium nitride is a GaN-based compound semiconductor. It is usually prepared by epitaxial growth, such as metalorganic chemical vapour deposition (MOCVD), molecular-beam epitaxy (MBE), pulsed laser deposition (PLD), etc. This material is used for specialist opto-electronics applications, often in blue laser diodes and LEDs.
A quantum-well laser is a laser diode in which the active region of the device is so narrow that quantum confinement occurs. Laser diodes are formed in compound semiconductor materials that are able to emit light efficiently. The wavelength of the light emitted by a quantum-well laser is determined by the width of the active region rather than just the bandgap of the materials from which it is constructed. This means that much shorter wavelengths can be obtained from quantum-well lasers than from conventional laser diodes using a particular semiconductor material. The efficiency of a quantum-well laser is also greater than a conventional laser diode due to the stepwise form of its density of states function.
Selective area epitaxy is the local growth of epitaxial layer through a patterned amorphous dielectric mask (typically SiO2 or Si3N4) deposited on a semiconductor substrate. Semiconductor growth conditions are selected to ensure epitaxial growth on the exposed substrate, but not on the dielectric mask. SAE can be executed in various epitaxial growth methods such as molecular beam epitaxy (MBE), metalorganic vapour phase epitaxy (MOVPE) and chemical beam epitaxy (CBE). By SAE, semiconductor nanostructures such as quantum dots and nanowires can be grown to their designed places.
Organogallium chemistry is the chemistry of organometallic compounds containing a carbon to gallium (Ga) chemical bond. Despite their high toxicity, organogallium compounds have some use in organic synthesis. The compound trimethylgallium is of some relevance to MOCVD as a precursor to gallium arsenide via its reaction with arsine at 700 °C:
IQE PLC is a British semiconductor company founded 1988 in Cardiff, Wales, which manufactures advanced epitaxial wafers for a wide range of technology applications for wireless, optoelectronic, electronic and solar devices. IQE specialises in advanced silicon and compound semiconductor materials based on gallium arsenide (GaAs), indium phosphide (InP), gallium nitride (GaN) and silicon. The company is the largest independent outsource producer of epiwafers manufactured by metalorganic vapour phase epitaxy (MOCVD), molecular beam epitaxy (MBE) and chemical vapor deposition (CVD).
Tantalum(V) ethoxide is a metalorganic compound with formula Ta2(OC2H5)10, often abbreviated as Ta2(OEt)10. It is a colorless solid that dissolves in some organic solvents but hydrolyzes readily. It is used to prepare films of tantalum(V) oxide.
Gallium arsenide antimonide, also known as gallium antimonide arsenide or GaAsSb, is a ternary III-V semiconductor compound; x indicates the fractions of arsenic and antimony in the alloy. GaAsSb refers generally to any composition of the alloy. It is an alloy of gallium arsenide (GaAs) and gallium antimonide (GaSb).
