  The electrical characteristics and microstructures of $\beta$-Ga$_2$O$_3$
Schottky barrier diode (SBD) devices irradiated with swift heavy ions (2096 MeV
Ta ions) have been studied. It was found that $\beta$-Ga$_2$O$_3$ SBD devices
showed the reliability degradation after irradiation, including turn-on voltage
Von, on-resistance Ron, ideality factor n and the reverse leakage current
density Jr. In addition, the carrier concentration of the drift layer was
decreased significantly and the calculated carrier removal rates were 5*106 -
1.3*107 cm-1. Latent tracks induced by swift heavy ions were observed visually
in the whole $\beta$-Ga$_2$O$_3$ matrix. Furthermore, crystal structure of
tracks was amorphized completely. The latent tracks induced by Ta ions
bombardments were found to be the reason for the decrease in carrier mobility
and carrier concentration. Eventually, these defects caused the degradation of
electrical characteristics of the devices. By comparing the carrier removal
rates, the $\beta$-Ga$_2$O$_3$ SBD devices were more sensitive to swift heavy
ions irradiation than SiC and GaN devices.
