kV-Class Vertical GaN PiN Diode Under Proton Irradiation: Impact on Conductivity Modulation

This work investigates the proton irradiation effect on a kV-class vertical GaN-on-GaN PiN diode under 10-MeV and 50-MeV proton irradiation with fluence up to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\times 10^{{14}}$ </tex-math></inline-formula> cm−2. After proton irradiation, the vertical GaN PiN diode can maintain a reverse blocking voltage higher than 1.7 kV, whereas the forward conduction performance has degraded with weakened conductivity modulation. This weakening of the photon-assisted conductivity modulation is possibly correlated with the suppression of near-band-edge emission and ultraviolet luminescence in the voltage-dependent electro-luminescence (EL) spectra. The understanding of the proton irradiation effect on vertical GaN power devices is valuable for applications in harsh radiation environments.