Single and multi-fin normally-off Ga 2 O 3 vertical transistors with a breakdown voltage over 2.6 kV

We demonstrate record-high performance in normally-off single and multi-fin b-Ga 2 O 3 vertical power transistors. The effective channel mobility is significantly improved up to ~130 cm2/V•s with a post-deposition annealing process. With a fin-channel width of 0.15 µm, true normally-off operation is achieved with a threshold voltage of >1.5 V; a record-high breakdown voltage of 2.66 kV (at V gs =0 V) and a specific on-resistance of 25.2 mW•cm2 are obtained in multi-fin devices, corresponding to a Baliga’s figure-of-merit of 280 MW/cm2, which is the highest among all Ga 2 O 3 transistors. Devices with (100)-like fin-channel sidewalls exhibit the lowest interface trapped charge density and a significantly higher current than other fin orientations. These findings offer important insights on the development of Ga 2 O 3 MOSFETs and show great promise of Ga 2 O 3 vertical power devices.