Thermal stability study of AlGaN/GaN MOS-HEMTs using Gd2O3 as gate dielectric

Thermal stability of AlGaN/GaN MOS-HEMTs and -diodes using Gd
2
O
3
are investigated by means of different thermal cycles and storage tests up to 500°C for one week. IV DC and pulsed characteristics of the devices before and after the processes are evaluated and compared with conventional HEMTs. Results show that the devices with Gd
2
O
3
dielectric layer have lower leakage current and a more stable behavior during thermal treatment processes compared with conventional devices. In fact, an excellent on/off ratio of about 10
⁸
and a stable V
t
is observed after storage at high temperature. The beneficial effects of Gd
2
O
3
on trapping effects of MOS-HEMTs are also discussed.