IEEE Workshop on Wide Bandgap Power Devices and Applications in Asia (WiPDA Asia 2018)

325 / 2017-12-08 20:12:40

AlGaN/GaN E-mode MOS-HEMT Using Atomic-Layer-Deposited HfLaO x as Gate Dielectric

E-mode,HEMT,High-k,Dielectric

Plenary track > Gate dielectrics and surface passivation

In this paper, we report GaN MOS-HEMTs with high quality atomic-layer-deposited HfLaO x as gate dielectric. The threshold voltage of recessed gate MOS-HEMT can be enhanced from -6.2 V to 0.8 V. The E-mode GaN MOS-HEMT exhibits ideal subthreshold swing ~ 66 mV/dec and high on-off ratio of 1.2×10^10 . Conductance method has been applied to reveal low Dit between high-κ/AlGaN interface. Effective mobility of D-mode and E-mode MOS-HEMTs are 1958 cm2/V·s and 1483 cm2/V·s, respectively. A high breakdown voltage of 840 V was achieved, thanks to suppressed gate leakage. The specific on-resistance of E-mode device is 1.86 mΩ·cm 2 and results in high power figure of merit (BV2 /Ron,sp ) of 380 MW/cm 2 .