New Inductively Coupled Plasma–Chemical Vapor Deposition SiO2 Passivation for High-Voltage Switching AlGaN/GaN Heterostructure Field-Effect Transistors

A new inductively coupled plasma–chemical vapor deposition (ICP–CVD) SiO 2 passivation for high-voltage switching AlGaN/GaN heterostructure field-effect transistors (HFETs) is proposed to increase the breakdown voltage and forward drain current. The AlGaN/GaN HFETs are fabricated and measured before and after the passivation. The measured off-state breakdown voltage of the passivated device is 455 V, whereas that of the unpassivated device is 282 V. The forward drain currents of the passivated devices are increased by 20–35% because the two-dimensional electron gas (2DEG) concentration is increased and the electron injections to the surface states are decreased.