High breakdown voltage in AlGaN/GaN/AlGaN double heterostructures grown on 4 inch Si substrates

We report high breakdown combined with low on‐resistance results on AlGaN/GaN/AlGaN double heterostructure devices (DHFET) grown on 4 inch Silicon substrates. On two fingers devices with gate‐drain distance (LGD) of 8 μm we measured a breakdown voltage (VBD) of 650 V and an on‐resistance (Ron) of 7.2 Ω·mm. We also demonstrated that increasing the buffer thickness and etching deep into the AlGaN buffer layer improve both buffer and device breakdown. Moreover, we have also achieved a high breakdown voltage (580 V) for smaller LGD (5 μm) combined with the lowest reported on‐resistance (6 Ω·mm) for this voltage range. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)