Defect Identification in β-Ga2O3 Schottky Barrier Diodes With Electron Radiation and Annealing Regulating

Identifying the impact of native/irradiated traps on electrical properties is vital for the implementation of high-performance gallium oxide (Ga2O3) power devices. In this work, the effect of electron irradiation and isochronal thermal annealing on the electrical properties of vertical Ni/Au
$\beta $
-Ga2O3 Schottky barrier diode is explored. Majority and minority carrier traps in Ni/Au
$\beta $
-Ga2O3 diode after irradiation and annealing are characterized using deep-level transient spectroscopy (DLTS) technique. We observe three trap states at
$E_{\mathrm {V}} + 0.402$
eV (H1),
$E_{\mathrm {C}} -0.626$
eV (E1), and
$E_{\mathrm {C}} -0.755$
eV (E2), in which electron trap E2 is dominant, and the instability of electrical properties of the tested sample is attributed to the electron trap E2. Combining the formation energies and transition levels of
$\beta $
-Ga2O3 intrinsic defects calculated by first-principles method, it is speculated that trap H1 is attributed to V
$_{\mathrm {GaI}}- 2$
V
$_{\mathrm {OII}}(+5/+3$
) or V
$_{\mathrm {GaII}}- 2$
V
$_{\mathrm {OII}}(+3/+1$
), trap E1 is related to V
$_{\mathrm {GaI}} - V_{\mathrm {OI}}(-1/-3$
) or O
$_{\mathrm {ic}}(-1/-2$
), and trap E2 is associated with O
$_{\mathrm {id}}(0/-2$
) or O
$_{\mathrm {GaII}}(-1/-3$
). Additionally, trap E2 is linked to the extrinsic defect FeGa. Based on the experimental and theoretical calculations of Ni/Au
$\beta $
-Ga2O3 diode, the exact physical origin of radiation-induced defects and its annealing derivation process are discussed in detail.