Effects of Neutron Irradiation on Electrical Performance of β-Ga₂ O₃ Schottky Barrier Diodes

The effect of neutron irradiation on the electrical performance of the <tex-math notation="LaTeX">β </tex-math> -Ga2O3 Schottky barrier diode (SBD) device has been studied in this work. After equivalent 1 MeV neutron irradiation with a fluence of <tex-math notation="LaTeX">1× 10^14 </tex-math> n/cm2, a 20% decrease in the forward current density ( <tex-math notation="LaTeX">JF) </tex-math> , a 75% reduction in the reverse current density ( <tex-math notation="LaTeX">JR) </tex-math> , and a 300 V increase in the breakdown voltage ( <tex-math notation="LaTeX">Vbr) </tex-math> have been observed according to current–voltage ( <tex-math notation="LaTeX">I </tex-math> – <tex-math notation="LaTeX">V) </tex-math> measurements. Utilizing the frequency-dependent conductance technique, it is found that the density of interface states located at Pt/Ga2O3 increases slightly from <tex-math notation="LaTeX">2.6× 10^12 </tex-math> – <tex-math notation="LaTeX">6.4× 10^12 </tex-math> to <tex-math notation="LaTeX">2.9× 10^12 </tex-math> – <tex-math notation="LaTeX">7.0× 10^12 </tex-math> cm <tex-math notation="LaTeX">^-2 </tex-math> eV <tex-math notation="LaTeX">^-1 </tex-math> with an increase in trap activation energy from 0.09–0.122 to 0.096–0.134 eV after neutron irradiation. Furthermore, based on the capacitance–voltage ( <tex-math notation="LaTeX">C </tex-math> – <tex-math notation="LaTeX">V) </tex-math> measurement, it is observed that the carrier concentration across the Ga2O3 drift layer was decreased from <tex-math notation="LaTeX">1.80× 10^16 </tex-math> to <tex-math notation="LaTeX">1.35× 10^16 </tex-math> cm <tex-math notation="LaTeX">^-3 </tex-math> after neutron irradiation. Considering the device performance change, it indicates that the bulk traps within the Ga2O3 drift layer instead of interface states dominate the device degradation.