Dual-gate AlGaN/GaN MIS-HEMTs using Si3N4 as the gate dielectric

We have investigated dual-gate AlGaN/GaN metal-insulator-semiconductor high-electron mobility transistors (MIS-HEMTs) using Si3N4 as the gate dielectric by comparison with singlegate MIS-HEMTs. It is shown that the presence of the second gate induces a slight reduction in the maximum output current, transconductance and breakdown voltage, but with the advantages of 5 dB enhanced power gain and higher fT/fmax. Combined with a physics-based device simulation, the breakdown characteristics of the dual-gate device are revealed to be dependent on the second gate. These results demonstrate that the incorporation of dual-gate configuration into the MIS gate is a potential alternative for GaN-based high-power and high-frequency applications.