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 (L-GD) of 8 mu m we measured a breakdown voltage (V-BD) of 650 V and an on-resistance (R-on) of 7.2 Omega.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 mu m) combined with the lowest reported on-resistance (6 Omega.mm) for this voltage range. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim