2.4 kV β-Ga2O3 SBDs With 1.22 GW/cm2 Figure of Merit by N2O Plasma Treatment

This work reports the effect of N2O plasma treatment at different temperatures on the performance of $\beta $ -Ga2O3 Schottky barrier diodes (SBDs). The results show that after $300~^{\circ }$ C N2O plasma treatment, the device leakage current decreased from $4\times 10^{-{9}}$ to $4\times 10^{-{10}}$ A/cm2, and the on-off ratio increased from $6\times 10^{{10}}$ to $5\times 10^{{11}}$ . Due to the passivation of surface states and oxygen vacancies by nitrogen and oxygen ions, the carrier concentration decreased from ${2}.{20}\times {10} ^{{16}}$ to ${1}.{61}\times {10} ^{{16}}$ cm ${}^{-{3}}$ . The improvement is attributed to the formation of a significant amount of Ga-N bonds on the sample surface, which results in the generation of a high-resistance N-doped $\beta $ -Ga2O3 layer. This further improves the device breakdown voltage (V ${}_{\text {br}}\text {)}$ from 664 V to 2,437 V with a power figure of merit (PFOM) of 1.22 GW/cm2. Our breakdown electric field (E ${}_{\text {br}}\text {)}$ is the highest among reported vertical $\beta $ -Ga2O3 SBDs without termination structure, and Vbr is the highest of devices with the same epitaxy thickness.