Design of GaN tri-gate HEMTs

The operation of GaN tri-gate HEMTs is investigated by numerical device simulations. It is shown that the threshold voltage of such structures strongly depends on the width of the AlGaN/GaN body and to a lesser extent on the body height. The body height becomes more important as the gate length is reduced. However, the beneficial effect of the side gates saturates at body heights around 100 nm, independent of the gate length.