The manufacturability of 1200 V-qualified buffer layers opens doors to highest voltage GaN-based power applications such as electric cars, previously only feasible with SiC-based technology. The result comes after the successful qualification of AIXTRON’s G5 C fully automated metal-organic chemical vapor deposition (MOCVD) reactor at Imec for integrating the optimized material epi-stack. “GaN can now become the technology of choice for a whole range of operating voltages from 20 V to 1200 V. Being processable on larger wafers in high-throughput CMOS fabs, power technology based on GaN offers a significant cost advantage compared to the intrinsically expensive SiC-based technology,” commented Denis Marcon, Senior Business Development Manager.

Key to achieving the high breakdown voltage is the careful engineering of the complex epitaxial material stack in combination with the use of 200 mm QST substrates, executed in scope of the IIAP program The CMOS-fab friendly QST substrates from Qromis have a thermal expansion that closely matches the thermal expansion of the GaN/AlGaN epitaxial layers, paving the way for thicker buffer layers – and hence higher voltage operation. “The successful development of this 1200 V GaN-on-QST epi-technology is a next step in our collaboration with Imec. Earlier, after having installed AIXTRON G5 C at Imec’s facilities, its proprietary 200 mm GaN-on-Si materials technology was qualified on our G5 C high-volume manufacturing platform, targeting for example high-voltage power switching and RF applications and enabling our customer to achieve a rapid production ramp-up by pre-validated available epi-recipes. With this new achievement, we will be able to jointly tap into new markets,” said Felix Grawert, CEO and President of AIXTRON.

Currently, lateral e-mode devices are being processed to prove device performance at 1200 V, and efforts are ongoing to extend the technology towards even higher voltage applications. Next to this, Imec is also exploring 8-inch GaN-on-QST vertical GaN devices to further extend the voltage and current range of GaN-based technology. AS

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