Square-Gate AlGaN/GaN HEMTs With Improved Trap-Related Characteristics

In this brief, the trap-related characteristics of high-breakdown AlGaN/GaN high-electron-mobility transistors (HEMTs) were investigated. Compared with a conventional multifinger layout, the square-gate design presented reduced the current collapse from 19% to 6% and almost eliminated the gate lag. The flicker noise density and the gate leakage decreased from 1.16 times10
^-10
to 1.17 times10
^-11
1/Hz (
f
= 100 Hz) and from 7.36 times10
^-5
to 1.80 times10
^-6
A/mm (
V

_GS
= -4 V and
V

_DS
= 100 V), respectively. The breakdown voltage was also improved from 350 to 650 V. With the channel area away from the defects generated by the mesa etching process, the square-gate AlGaN/GaN HEMTs demonstrated excellent performance with much less trapping effects.