a -plane GaN-based fully vertical FinFETs with normally-off operation

In this work, the electrical performance of fully vertical single-fin a -plane gallium nitride fin-based field-effect transistors (FinFETs) with short gate length ( L g ≈ 200nm) and a drift-layer thickness of 4.3 µ m is investigated. Device characteristics are evaluated over a temperature range from 25 ° C to 150 ° C for various fin widths. The FinFETs exhibit stable normally-off operation across the entire temperature range. For a device with a fin width of 100nm, a positive threshold voltage of 1.7 V is achieved and remains stable up to 150 ° C. The same device demonstrates a specific on-resistance of 3 mΩ·cm 2 , a minimum subthreshold swing of 63mV dec −1 , an ON/OFF current ratio of approximately 10 10 and a current density of 2.4kA cm −2 (133kA cm −2 when normalized to the single-fin active area, including current spreading in the drift layer). An increase in threshold voltage with temperature, particularly at 150 ° C, is observed, indicating robust electrostatic control and favorable thermal stability for high-temperature power device operation.