High-Quality MgO/TiO₂/MgO Nanolaminates on p-GaN MOS Capacitor

In this letter, the electrical characteristics of nanolaminate MgO/TiO2/MgO on a p-GaN MOS capacitor with and without postmetallization annealing (PMA) and (NH4)2Sx, treatments are investigated. With both PMA and (NH4)2Sx, treatments, the leakage current densities are reduced to 3.9 × 10-8and 3.7 × 10-8A/cm2at ±1 V, respectively. With a much-improved C-V curve, the effective dielectric constant of the gate dielectric stack for both treatments is 17.8, and an averaged interface trap density of 3.1 × 1011eV-1cm-2is obtained.