Breakdown Characteristics of β -(Al0.22Ga0.78)₂O₃/Ga₂O₃ Field-Plated Modulation-Doped Field-Effect Transistors

We investigate voltage breakdown of a β-(Al0.22Ga0.78)2O3/Ga2O3modulation-doped field-effect transistor with a gate-connected field-plate and silicon nitride (SiNx) as the passivation layer. Breakdown characteristics were found to be limited by the Schottky gate. We demonstrate a high breakdown voltage of 1.37 kV for a gate-to-drain separation (LGD) of 16 μm with a specific ON-resistance of 120.1 mQ · cm2. A high average electric field of 3.9 MV/cm is extracted for LGD = 320 nm. The reported results suggest SiNxas a potential passivation dielectric for Ga2O3.