7.05 W/mm Power Density Millimeter-Wave GaN MIS-HEMT With Plasma Enhanced Atomic Layer Deposition SiN Dielectric Layer

Plasma enhanced atomic layer deposition (PEALD) SiN gate dielectric is performed on AlGaN/GaN metal-insulator-semiconductor high-electron-mobility transistor (MIS-HEMT). The fabricated MIS-HEMTs with 5 nm SiN gate dielectric layer exhibits a tiny threshold voltage hysteresis (~ 0.04 V), sufficiently decreased leakage current of ~10−9 A/mm at ${V}_{\text {GS}} =-{60}$ V and good threshold voltage ( ${V}_{\text {TH}}$ ) stability even measured at 200 °C. The increased mobility of 2-D electron gas (2-DEG) and suppressed current collapse are demonstrated, thereby producing a power density of 7.05 W/mm with an associated 34.0 % power-added efficiency (PAE) and a peak PAE of 51.4 % in a continuous-wave mode at 30 GHz.