High-performance AlGaN/AlN/GaN high electron mobility transistor with broad gate-to-source operation voltages

In this article, a high‐performance AlGaN/AlN/GaN high electron mobility transistor (HEMT) with broad gate‐to‐source operation voltages is fabricated and demonstrated. The experimental results exhibit a maximum extrinsic transconductance of 94.2 mS/mm at VGS = ‐2.58 V and a threshold voltage of ‐3.68 V at drain output current of 1 mA/mm.The insertion of an AlN interfacial layer can enhance the carrier confinement ability in channel and extend the gate operation voltage to +5 V. Furthermore, the effect of gate recess on device performance is investigated by two‐dimensional simulation. The simulated results show that the AlGaN/AlN/GaN HEMT with gate recess structure has higher equivalent Schottky barrier height, larger electron concentration in channel, larger drain output current and transconductance as compared with the device without gate recess structure. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)