Deeply-scaled GaN-on-Si high electron mobility transistors with record cut-off frequency f T of 310 GHz

Abstract

A deeply-scaled GaN-on-Si high electron mobility transistor with a record-high cut-off frequency (f T) of 310 GHz has been demonstrated. The device has an InAlN/GaN heterojunction structure, a source-drain spacing of 400 nm, and a gate length of 40 nm. The device exhibited a high drain current of 2.34 A mm-1, a peak transconductance of 523 mS mm-1, and a gate-to-drain breakdown voltage (BV gd) of 15 V. A Johnson's figure-of-merit (FOM = f T × BV) of 4.65 THz V has been achieved, which is comparable to those reported in GaN-on-SiC. These results indicate GaN-on-Si transistors are promising in low-cost emerging mm-wave applications.