| Aluminium nitride[1] | |
|---|---|
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| Other names | Aluminum nitride |
| Identifiers | |
| CAS number | [24304-00-5] |
| Properties | |
| Molecular formula | AlN |
| Molar mass | 40. CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) 988 g mol-1 |
| Density | 3260 kg m-3 |
| Melting point |
2200 °C |
| Boiling point |
2517 °C |
| Thermal conductivity | 140–180 W m-1 K-1 |
| Thermochemistry | |
| Specific heat capacity, C | 740 J Kg-1 K-1 |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Aluminium nitride (AlN) is a nitride of aluminium. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different The melting point of a solid is the temperature range at which it changes state from solid to Liquid. The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid In Physics, thermal conductivity, k is the property of a material that indicates its ability to conduct Heat. Specific heat capacity, also known simply as specific heat, is the measure of the heat energy required to increase the Temperature of a unit quantity In Chemistry, the standard state of a material is its state at 1 bar (100 Kilopascals exactly WikipediaNaming Nitrogen (ˈnaɪtɹəʤɪn is a Chemical element that has the symbol N and Atomic number 7 and Atomic weight 14 In chemistry a nitride is a compound of Nitrogen with a less Electronegative element where nitrogen has an Oxidation state of -3 WikipediaNaming Its wurtzite phase (w-AlN) is an extremely wide bandgap (6. This article is about the mineral wurtzite For the wurtzite crystal structure see Wurtzite (crystal structure. 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 Wide bandgap semiconductors are Semiconductor materials with electronic Band gaps larger than one or two Electronvolts (eV 2 eV) semiconductor material which has potential application for deep ultraviolet optoelectronics. A semiconductor' is a Solid material that has Electrical conductivity in between a conductor and an insulator; it can vary over that Ultraviolet ( UV) light is Electromagnetic radiation with a Wavelength shorter than that of Visible light, but longer than X-rays Optoelectronics is the study and application of electronic devices that source detect and control Light, usually considered a sub-field of Photonics.
Contents |
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). Year 1877 ( MDCCCLXXVII) was a Common year starting on Monday (link will display the full calendar of the Gregorian calendar (or a Common In Physics, thermal conductivity, k is the property of a material that indicates its ability to conduct Heat. 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. Zinc sulfide (or zinc sulphide is a Chemical compound with the formula Zn[[Sulfur S]] This article is about the mineral wurtzite For the wurtzite crystal structure see Wurtzite (crystal structure. The space group for this structure is P63mc.
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 aluminium nitride grains. The material hydrolyzes slowly in water. Aluminium nitride is resistant to attack from most molten salts including chlorides and cryolite. Melting is a process that results in the phase change of a substance from a Solid to a Liquid. The chloride Ion is formed when the element Chlorine picks up one Electron to form an Anion (negatively-charged ion Cl&minus Cryolite ( Na 3 Al[[fluorine F]]6 Sodium hexafluoroaluminate) is an uncommon Mineral identified with the once large deposit
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. Sintering is a method for making objects from powder, by heating the material (below its Melting point - solid state sintering until its particles adhere
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. Gallium nitride ( is a very hard material commonly used in bright LEDs since the 1990s Aluminium gallium nitride ( AlGaN) is a Semiconductor material. 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. In Solid state physics and related applied fields a band gap, also called an energy gap or bandgap, is an energy range in a solid where no electron states 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.
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. Epitaxy refers to the method of depositing a Monocrystalline film on a monocrystalline substrate A surface acoustic wave ( SAW) is an Acoustic wave traveling along the surface of a material having some elasticity, with an Amplitude that A wafer is a thin slice of Semiconductor material such as a Silicon crystal used in the fabrication of Integrated circuit and other microdevices Piezoelectricity is the ability of some materials (notably Crystals and certain Ceramics including bone to generate an Electric potential in response to Very few places can reliably fabricate these thin films. Thin films are thin material layers ranging from fractions of a Nanometre to several Micrometres in thickness Agilent after more than a decade of research now has a RF filter used in mobile phone called the FBAR. Electronic filters are Electronic circuits which perform Signal processing functions specifically intended to remove unwanted signal components and/or enhance wanted Thin Film Bulk Acoustic Resonator (FBAR or FBARs is a device consisting of a Piezoelectric material sandwiched between two Electrodes and acoustically de-coupled This technology is closely associated with engineers working in the MEMS field. Microelectromechanical systems ( MEMS) is the technology of the very small and merges at the nano-scale into Nanoelectromechanical systems (NEMS and Nanotechnology
See also
References
- ^ Aluminum Nitride. Boron nitride ( BN) is a binary chemical compound, consisting of equal numbers of Boron and Nitrogen atoms Aluminium phosphide is the Chemical compound with the formula AlP Indium nitride ( is a small bandgap semiconductor material which has potential application in Solar cells and high speed electronics Accuratus.
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