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Posts Tagged ‘Military’

Gallium Nitride for Power Applications

Monday, May 15th, 2017

Gabe Moretti, Senior Editor

Gallium nitride (GaN) has long been used in LED devices and other optoelectronic devices with high power and high frequency requirements.  It can work at much higher temperatures and voltages than gallium arsenide (GaAs) for example and thus it is also used in military and space applications.

A few days ago X-FAB and Exagan announced that they have produced GaN-on-Silicon devices on 200-mm wafers.

X-FAB, whose headquarter is in Germany, is a leading analog/mixed-signal and MEMS foundry group manufacturing silicon wafers for automotive, industrial, consumer, medical and other applications.  The company operates one fab in the USA, specifically in Lubbock Texas where it fabricates mixed-signal devices.  It also operates other fabs both in Europe and in Asia.

Founded in 2014 with support from CEA-Leti and Soitec, Exagan is based in Grenoble, France.  its mission is to accelerate the power electronics industry’s transition from silicon-based technology to GaN-on-silicon technology, enabling smaller and more efficient electrical converters.

The two companies have demonstrated mass-production capability to manufacture highly efficient high-voltage power devices on 200-mm GaN-on-silicon wafers using X-FAB’s standard CMOS production facility in Dresden, Germany.

Exagan and X-FAB have successfully resolved many of the challenges related to material stress, defectivity and process integration while using standard fabrication equipment and process recipes. Combined with the use of 200-mm wafers, this will significantly lower the cost of mass producing GaN-on-silicon devices. By enabling greater power integration than silicon ICs, GaN devices can improve the efficiency and reduce the cost of electrical converters, which will accelerate their adoption in applications including electrical vehicle charging stations, servers, automobiles and industrial systems.

The industry’s previous work with GaN had been limited to 100-mm and 150-mm wafers due to the challenges of layering GaN films on silicon substrates. Exagan’s G-Stack technology enables GaN-on-silicon devices to be manufactured more cost effectively on 200-mm substrates by depositing a unique stack of GaN and strain-management layers that relieves the stress between GaN and silicon layers. The resulting devices have been shown to exhibit high breakdown voltage, low vertical leakage and high-temperature operation.

The new GaN-on-silicon devices have been built using substrates fabricated at Exagan’s 200- mm epi-manufacturing facility in Grenoble, France. These epi wafers meet the physical and electrical specifications to produce Exagan’s 650-volt G-FET devices as well as the tight requirements for compatibility with CMOS manufacturing lines.