Impact of fluorine plasma and electrothermal annealing on the interfacial properties at Ni/ β -Ga 2 O 3 Schottky contacts

Abstract The interfacial properties of Schottky contacts crucially affect the performance of power devices. While a few studies have explored the impact of fluorine on Schottky contacts, a comprehensive theoretical explanation supported by experimental evidence remains lacking. This work investigates the effects of fluorine incorporation and electrothermal annealing (ETA) on the current transport process at Ni/ β -Ga 2 O 3 Schottky contacts. X-ray photoelectron spectroscopy and first-principles calculations confirm the presence of fluorine substitutions for oxygen and oxygen vacancies and their lowering effect on the Schottky barrier heights. Additionally, accurate electrothermal hybrid TCAD simulations validates the extremely short-duration high temperatures (683 K) induced by ETA, which facilitates lattice rearrangement and reduces interface trap states. The interface trap states are quantitatively resolved through frequency-dependent conductance technique, showing the trap density ( D T ) reduction from (0.88−2.48) × 10 11 cm −2 ·eV −1 to (0.46−2.09) × 10 11 cm −2 ·eV −1 . This investigation offers critical insights into the β -Ga 2 O 3 contacts with the collaborative treatment and solids the promotion of high-performance β -Ga 2 O 3 power devices.