Abstract
We propose a new type of 2-D electron gas field-effect transistor (TEGFET) in which the top gate is replaced by two lateral gates (LGs), separated on each side of the conducting channel by a trench. In the etched trenches, air acts as a dielectric. The presence of LGs changes the channel potential, which in turn shapes the drain current. Thus, the drain current can be adjusted by the gates’ bias. This LG-TEGFET avoids the reliability problems due to the top gate: suppression of the electric field perpendicular to the 2DEG plane, reduction of the in-plane electric field, very low leakage current through the LGs, and no gate/semiconductor interface, which means reduced interface defects and reduced degradation due to heavy ions or high-energy particles and electromagnetic irradiation. Throughout the 1.5–300 K temperature range, the system exhibits very flat and stable saturations of the current–voltage characteristics, which are satisfactorily modified when a VGS gate bias is applied to both LGs, or between the LGs. Our study suggests that this new TEGFET could be used in a wide range of applications involving III-V, III-V-N, and other devices.