Investigation on Electrical Performance Degradation Mechanism of β-Ga₂O₃ Schottky Barrier Diodes Under 3 MeV Proton Radiation

The influence of proton radiation on the electrical performance of the gallium oxide (Ga2O3) Schottky barrier diode (SBD) was investigated from the perspective of defect in this work. The electrical performance is significantly degraded with the increase of proton irradiation fluence. After the irradiation fluence of
$2\times 10^{{13}}$
p/cm2, it was found that the ON-state current density (
${J}_{\text {on}}$
) was reduced by 57%, the OFF-state current density (
${J}_{\text {off}}$
) was reduced by more than one order of magnitude, and the breakdown voltage (
${V}_{\text {br}}$
) increased by nearly 350 V. Based on the frequency-dependent conductance technique, the Ni/Ga2O3 interface changed slightly after proton irradiation. In addition, the deep-level transient spectroscopy (DLTS) measurements show that the concentration of the deep-level defect (
${E}_{c}$
-0.75 eV) within the Ga2O3 drift layer has a clear response to radiation, and was significantly increased from
$4.1\times 10^{{13}}$
cm-3 to
$5.4\times 10^{{14}}$
cm-3 after the irradiation with a fluence of
$2\times 10^{{13}}$
cm-2. Moreover, the carrier concentration extracted by capacitance-voltage (C–V) shows that the carrier removal rate caused by this defect is 550 cm-1. Considering the change of electrical performance, it indicates that the
${E}_{c}$
-0.75 eV defect within the Ga2O3 drift layer rather than the interface state determines the degradation of devices.