Radiation Resilience of $\beta$-Ga$_2$O$_3$ Schottky Barrier Diodes Under High Dose Gamma Radiation

TL;DR

This study demonstrates that $eta$-Ga$_2$O$_3$ Schottky diodes maintain high radiation resilience under gamma doses up to 5 Mrad, showing initial performance degradation followed by partial recovery due to radiation annealing effects.

Contribution

It provides the first systematic analysis of $eta$-Ga$_2$O$_3$ SBDs' electrical behavior under high-dose gamma radiation, revealing their potential for radiation-hardened applications.

Findings

Initial radiation causes decrease in on-current and increase in on-resistance.

Partial performance recovery occurs at higher doses due to radiation annealing.

Device maintains high breakdown voltage after irradiation.

Abstract

A systematic investigation of the electrical characteristics of \b{eta}-Ga2O3 Schottky barrier diodes (SBDs) has been conducted under high-dose 60Co gamma radiation, with total cumulative doses reaching up to 5 Mrad (Si). Initial exposure of the diodes to 1 Mrad resulted in a significant decrease in on-current and an increase in on-resistance compared to the pre-radiation condition, likely due to the generation of radiation-induced deep-level acceptor traps. However, upon exposure to higher gamma radiation doses of 3 and 5 Mrad, partial recovery of the device performance occurred, attributed to a radiation annealing effect. The capacitance-voltage (C-V) characterization revealed that the net carrier concentration in the $\beta$-Ga$_2$O$_3$ drift layer reduced from $\sim$3.19 $\times$ 10$^{16}$ cm$^{-3}$ to $\sim$3.05 $\times$ 10$^{16}$ cm$^{-3}$ after 5 Mrad (Si) irradiation. Temperature-dependent I-V characteristics showed that irradiation leads to a reduction in both forward and reverse current across all investigated temperatures ranging from 25 to 250$^\circ$C, accompanied by slight increases in on-resistance, ideality factors, and Schottky barrier heights. The reverse breakdown characteristics of the $\beta$-Ga$_2$O$_3$ SBDs showed a slight increase of the breakdown voltage after radiation. Overall, $\beta$-Ga$_2$O$_3$ Schottky diode exhibits high resilience to gamma irradiation, with performance degradation mitigated by radiation-induced self-recovery, highlighting its potential for radiation-hardened electronic applications in extreme environments.