High transconductance enhancement-mode AlGaN∕GaN HEMTs on SiC substrate

Abstract

Using inductively-coupled-plasma reactive ion etching (ICP-RIE), recessed 1 µm gate-length enhancement-mode (E-mode) AlGaN/GaN high electron mobility transistors (HEMTs) were fabricated. These 1 µm gate-length devices exhibited maximum drain current density of 470 mA/mm, extrinsic transconductance of 248 mS/mm and threshold voltage of 75 mV. These characteristics are much higher than previously reported values for GaN-based E-mode HEMTs. A unity gain cutoff frequency (fT) of 8 GHz and a maximum frequency of oscillation (fmax) of 26 GHz were also measured on these devices.