Monolithic Bidirectional GaN-on-GaN Vertical Transistor Technologies: Exploring Bidirectional CAVET for Next-Generation Switching Applications with Symmetrical Power Control

In this study, we designed and experimentally demonstrated a monolithic-integrated bidirectional GaN-on-GaN trench current aperture vertical electron transistor (BD-CAVET), capable of current conduction and voltage blocking in both directions. The trench CAVET was grown on a GaN substrate and incorporated a highly conductive 2D electron gas (2DEG) channel with a peak field effect mobility (μFE) of 1,792 cm2/(V·s). The BD-CAVET exhibited symmetricalI–Vcharacteristics in bidirectional mode, achieving a specific on-resistance (Ron,sp) of 2.5 mΩ·cm2and a breakdown voltage of 200 V in both the first and third quadrants. In single-directional mode, the BD-CAVET conducted current in one direction with a turn-on offset voltage of 1 V. Reverse conduction of the fabricated trench CAVET was also investigated, revealing that the primary path for reverse current flow was through the 2DEG channel.