Electrical Characteristics and Defect Dynamics Induced by Swift Heavy Ion Irradiation in Pt/PtO/-Ga₂O₃ Vertical Schottky Barrier Diodes

In situ
${I}$
–
${V}$
and
${C}$
–
${V}$
measurements were performed on Pt/PtOx/
$\beta $
-Ga2O3 vertical Schottky barrier diodes (SBD) during 120 MeV Au9+ swift heavy ion (SHI) irradiation in a fluence range of
$1\times 10^{{10}}$
–
$2\times 10^{{12}}$
ions/cm2. The reverse leakage current density increased from
$1.21\times 10^{-{10}}$
to
$1.69\times 10^{-{4}}$
A/cm2 at −1 V. The Schottky barrier height (SBH) remains close to ~1.8 eV up to the fluence of
$5\times 10^{{11}}$
ions/cm2, and however, at the fluences of
$1\times 10^{{12}}$
and
$2\times 10^{{12}}$
ions/cm2, the SBH increased to 1.93 and 2.03 eV, respectively. Also, the ideality factor (IF) increased from 1.07 to 1.38. The in situ
${C}$
–
${V}$
measurements showed a similar trend, as the SBH decreased from 2.04 to ~1.88 eV until
$5\times 10^{{11}}$
ions/cm2, but it increased to 2.14 and 2.56 eV at
$1\times 10^{{12}}$
and
$2\times 10^{{12}}$
ions/cm2, respectively. In addition, the doping concentration decreased from
$1.01\times 10^{{16}}$
to
$0.27\times 10^{{16}}$
cm
$^{-{3}}$
as the defects increased significantly at the fluence of
$2\times 10^{{12}}$
ions/cm2. The cathodoluminescence measurements revealed various Ga and O defects produced during SHI irradiation. Cross-sectional transmission electron microscopy measurements confirmed the formation of tracks within
$\beta $
-Ga2O3 along the SHI path, and these results are explained with the inelastic thermal spike model.