Aluminium nitride
Other names	aluminium nitride
Identifiers
CAS number	24304-00-5
Properties
Molecular formula	AlN
Molar mass	40.988g/mol
Appearance	crystalline solid, bluish white
Melting point	2200 °C Image File history File links No higher resolution available. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... A chemical formula is a concise way of expressing information about the atoms that constitute a particular chemical compound. ... Molar mass is the mass of one mole of a chemical element or chemical compound. ... The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. ...
Boiling point	2517 °C Italic text This article is about the boiling point of liquids. ...
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Aluminium nitride (AlN) is a nitride of aluminium. Its wurtzite phase (w-AlN) is an extremely wide bandgap (6.2 eV) semiconductor material which has potential application for deep ultraviolet optoelectronics. The plimsoll symbol as used in shipping In chemistry, the standard state of a material is its state at 1 bar (100 kilopascals exactly). ... Aluminum redirects here. ... General Name, symbol, number nitrogen, N, 7 Chemical series nonmetals Group, period, block 15, 2, p Appearance colorless gas Standard atomic weight 14. ... Definition The nitride ion is very very gay and retarded A nitride (compound) is a compound that has nitrogen with more electropositive elements. ... Aluminum redirects here. ... Zinc sulfide is a chemical compound with the formula ZnS. Zinc sulfide is a white to yellow colored powder or crystal. ... In the physical sciences, a phase is a set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties (i. ... Wide Bandgap Semiconductors have applications in optoelectronic and power devices. ... Semiconductor materials are insulators at absolute zero temperature that conduct electricity in a limited way at room temperature (see also Semiconductor). ... Ultraviolet (UV) radiation is electromagnetic radiation of a wavelength shorter than that of the visible region, but longer than that of soft X-rays. ... Optoelectronics is the study and application of electronic devices that interact with light. ...

History

AlN was first synthesised in 1877, but it was not until the middle of the 1980s that its potential for application in microelectronics was realised due to its relative high thermal conductivity for an electrical insulating ceramic (70-210 W•m⁻¹•K⁻¹ for polycrystalline material, and as high as 275 W•m⁻¹•K⁻¹ for single crystals). 1877 (MDCCCLXXVII) was a common year starting on Monday (see link for calendar). ... K value redirects here. ... Fixed Partial Denture, or Bridge The word ceramic is derived from the Greek word κεραμικός (keramikos). ...

Chemical description and properties

Aluminium nitride is a (mostly) covalently bonded material, and has a hexagonal crystal structure which is isomorphic with one of the polytypes of zinc sulfide known as wurtzite. The space group for this structure is P6_3mc. Zinc sulfide (or zinc sulphide) is a chemical compound with the formula ZnS. Zinc sulfide is a white to yellow colored powder or crystal. ... Zinc sulfide is a chemical compound with the formula ZnS. Zinc sulfide is a white to yellow colored powder or crystal. ...

The material is stable at very high temperatures in inert atmospheres. In air, surface oxidation occurs above 700°C, and even at room temperature, surface oxide layers of 5-10 nm have been detected. This oxide layer protects the material up to 1370°C. Above this temperature bulk oxidation occurs. Aluminium nitride is stable in hydrogen and carbon dioxide atmospheres up to 980°C.

The material dissolves slowly in mineral acids through grain boundary attack, and in strong alkalis through attack on the aluminum nitride grains. The material hydrolyzes slowly in water. Aluminium nitride is resistant to attack from most molten salts including chlorides and cryolite. Physics In physics, melting is the process of heating a solid substance to a point (called melting point) where it turns liquid. ... The chloride ion is formed when the element chlorine picks up one electron to form the negatively charged ion Cl−. The salts of hydrochloric acid HCl are also called chlorides. ... It has been suggested that this article or section be merged with sodium hexafluoroaluminate. ...

Manufacture

AlN is synthesised by carbothermal reduction of alumina or by direct nitridation of aluminium. The use of sintering aids and hot pressing is required to produce a dense technical grade material. Alumina redirects here. ... This article or section does not cite its references or sources. ...

Applications

Metallization methods are available to allow AlN to be used in electronics applications similar to those of alumina and BeO.

Currently there is much research into developing light-emitting diodes to operate in the ultraviolet using the gallium nitride based semiconductors and, using the alloy aluminium gallium nitride, wavelengths as short as 250 nm have been reported. In May 2006 an inefficient LED emission at 210 nm was reported [1]. The bandgap of single crystal AlN has been measured (using vacuum UV reflectivity) at 6.2 eV. This allows a wavelength of around 200 nm to be achieved, in principle. However, there are many difficulties to be overcome if such emitters are to become a commercial reality. “LED” redirects here. ... Gallium nitride (GaN) is a wide bandgap semiconductor material used in optoelectronic, high-power and high-frequency devices. ... Aluminium gallium nitride (AlGaN) is a semiconductor material. ... In solid state physics and related applied fields, the band gap is the energy difference between the top of the valence band and the bottom of the conduction band in insulators and semiconductors. ...

Among the applications of AlN are

• opto-electronics,
• dielectric layers in optical storage media,
• electronic substrates, chip carriers where high thermal conductivity is essential,
• military applications.

Epitaxially grown crystalline aluminum nitride is also used for surface acoustic wave sensors (SAW's) deposited on silicon wafers because of the AlN's piezoelectric properties. Very few places can reliably fabricate these thin films. Agilent after more than a decade of research now has a RF filter used in mobile phone called the FBAR. This technology is closely associated with engineers working in the MEMS field. Epitaxy is the growth of crystals of one material on the crystal face of another (heteroepitaxy) or the same (homoepitaxy) material, such that the two materials have a defined relative structural orientation. ... A surface acoustic wave (SAW) is a kind of wave used in piezoelectric devices called SAW devices in electronics circuits. ... It has been suggested that Wafer prober be merged into this article or section. ... Piezoelectricity is the ability of certain crystals to produce a voltage when subjected to mechanical stress. ... Thin films are material layers of about 1 µm thickness. ... Television signal splitter consisting of a hi-pass filter (left) and a low-pass filter (right). ... Thin Film Bulk Acoustic Resonator (FBAR) or FBARs is a device consisting of a piezoelectric material sandwiched between two electrodes and acoustically de-coupled from the surrounding medium. ... A mite less than 1 mm on a MEMS device. ...

See also

• Boron nitride
• Aluminium phosphide
• Indium nitride

Boron nitride is a binary chemical compound, consisting of equal proportions of boron and nitrogen, with formula BN. Structurally, it is isoelectronic to carbon and takes on similar physical forms: a hexagonal, graphite-like one, and a cubic, diamond-like one. ... Aluminium phosphide (AlP) is a compound of aluminium and phosphorus. ... Indium nitride (InN) is a small bandgap semiconductor material which has potential application for solar cells and high speed electronics. ...

References

This article does not cite any references or sources. (September 2007) Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed.

Image File history File links Question_book-3. ...

Academic

• Ioffe data archive
• Electronic Structure of AlN
• MSDS (University of Oxford)

Commercial suppliers

• Ceramic Substrates and Components Ltd
• Goodfellow
• NanoAmor's AlN Nanoparticles