Electrical Characteristics of AlGaN/GaN High-Electron-Mobility Transistors Fabricated with a MgF 2 Passivation Layer

We have demonstrated AlGaN/GaN high-electron-mobility transistors (HEMTs) fabricated with aMgF 2 passivation layer. Upon MgF 2 passivation using an e-beam evaporator, the HEMT showed a maximum drain saturation current of 508 mA/mm, a maximum transconductance of 136 mS/mm, a significantly reduced gate forward leakage current, a low gate reverse leakage current of 1.8 × 10 −7 A/mm at gate bias voltage of −10 V, and an increased breakdown voltage of 563 V. This suggests that the MgF 2 film is quite useful as a passivation layer for AlGaN/GaN HEMTs.