X-FAB Silicon Foundries AG of Erfurt, Germany and Exagan of Grenoble, France, a gallium nitride (GaN) technology start-up enabling smaller and more efficient electrical converters, have demonstrated mass-production capability for manufacturing highly efficient high-voltage power devices on 200mm GaN-on-silicon wafers using X-FAB’s standard CMOS production facility in Dresden, Germany. The achievement is the result of a joint development agreement launched in 2015, enabling cost/performance advantages that could not be achieved with smaller wafers.
Exagan and X-FAB say that they have 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 200mm wafers, this can significantly lower the cost of mass producing GaN-on-Si devices. By enabling greater power integration than silicon ICs, GaN devices can improve the efficiency and reduce the cost of electrical converters, which is expected to accelerate their adoption in applications including electrical vehicle charging stations, servers, automobiles and industrial systems.
The new GaN-on-Si devices have been built using substrates fabricated at Exagan’s 200mm epitaxy manufacturing facility in Grenoble, France. These epiwafers meet the physical and electrical specifications to produce Exagan’s 650V G-FET devices as well as the tight requirements for compatibility with CMOS manufacturing lines.
GaN industrial production has been limited to 100mm and 150mm wafers due to the challenges of layering GaN films on silicon substrates. Exagan says that its G-Stack technology enables GaN-on-Si devices to be manufactured more cost effectively on 200mm 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.
“This is a major milestone in our company’s development as we accelerate product development and qualification,” states Exagan’s president & CEO Frédéric Dupont. “It demonstrates the combined strengths of our epi material, X-FAB’s wafer fab process and our device design capabilities. It also confirms the success of our vertically integrated fab-lite model, with expertise from materials to devices and applications. It is perfect timing to establish GaN technology and products on the most competitive 200mm platform just as GaN power products are getting broad traction in IT server, consumer electronics and automotive markets,” he adds.
“Through this productive partnership, X-FAB is leveraging its resources and expertise to bring Exagan’s technology into manufacturing and provide the power conversion market with a reliable supply chain,” says X-FAB’s Rudi De Winter.
Exagan is showcasing its GaN technology and G-FET transistors in booth #9-230 at the PCIM (Power Conversion Intelligent Motion) Europe trade show in Nuremberg, Germany (16-18 May).