Performance improvement of normally off AlGaN/GaN FinFETs with fully gate-covered nanochannel

•The pulse measurements for the AlGaN/GaN FinFETs with normally-off operation.•The proposed FinFET exhibits the reduced gate/drain lag.•The device also shows high on-state performances for high current operation.

Normally-off AlGaN/GaN FinFETs have been fabricated by fully covering the nanochannel region with a metal gate. Removing the source/drain extensions (gate underlap regions) greatly decreases the access resistance of the device, which results in an order of magnitude higher on-current and transconductance. As compared with earlier HEMT FinFETs, where the nanochannel is only partially covered by the gate, the carrier trapping at the surface and in the buffer layer is effectively reduced, improving the gate and the drain lags.