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

A deeply-scaled GaN-on-Si high electron mobility transistor with a record-high cut-off frequency (f(T)) of 310GHz has been demonstrated. The device has an InAlN/GaN heterojunction structure, a source?drain spacing of 400nm, and a gate length of 40nm. The device exhibited a high drain current of 2.34Amm(?1), a peak transconductance of 523mSmm(?1), and a gate-to-drain breakdown voltage (BVgd) of 15V. A Johnson?s figure-of-merit (FOM=f(T)BV) of 4.65THz 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.