Scaled T-Gate β-Ga₂O₃ MESFETs With 2.45 kV Breakdown and High Switching Figure of Merit

We demonstrate a passivated MESFET fabricated on (010) Si-doped $\beta $ -Ga ₂ O ₃ with breakdown over 2.4 kV without field plates, high Power Figure of Merit (PFOM), and high estimated Huang’s Material Figure of Merit (HMFOM), owing to low gate charge and high breakdown. MESFETs with 13 $\mu \text{m}$ source-drain spacing and 75 nm channel exhibited a current density of 61 mA/mm, peak transconductance of 27 mS/mm, and on-resistance of ${133}~\Omega \cdot \text {mm}$ . The device showed a PFOM competitive with state-of-the-art $\beta $ -Ga ₂ O ₃ devices and a record high estimated HMFOM for a $\beta $ -Ga ₂ O ₃ device, competitive with commercial wide-band gap devices. This demonstrates high-performance $\beta $ -Ga ₂ O ₃ devices as viable multi-kV high-voltage power switches.