High Performance Al0.10Ga0.90N Channel HEMTs

Abstract

This letter reports the large maximum drain current AlGaN channel high-electron-mobility transistors (HEMTs) of 849 mA/mm with graded buffers and constant channel layer. The large drain current and the transconductance benefit from the high electronic mobility of 807 cm2/ $\mathrm {V}\cdot \mathrm {s}$ and high saturated velocity. Furthermore, the device also shows a low off-state drain current of ~1 nA/mm and an ultrahigh ${I} _{ \mathrm{\scriptscriptstyle ON}}/{I} _{ \mathrm{\scriptscriptstyle OFF}}$ up to ~109. To the best of the authors’ knowledge, the electronic mobility, the maximum drain current, and ${I} _{ \mathrm{\scriptscriptstyle ON}}/{I} _{ \mathrm{\scriptscriptstyle OFF}}$ ratio all are the largest reported results ever achieved on the AlGaN channel HEMTs. These results not only drastically reduce the performance gaps between the AlGaN channel HEMT and the GaN channel HEMT in the maximum drain current, the maximum transconductance, and the electronic mobility, but also demonstrate better performances in the gate leakage current, the off-state drain current, ${I} _{ \mathrm{\scriptscriptstyle ON}}/{I} _{ \mathrm{\scriptscriptstyle OFF}}$ ratio, and the breakdown voltage.