Effect of electron-beam irradiation on leakage current of AlGaN/GaN HEMTs on sapphire

Abstract

This study examined the effect of electronbeam (E-beam) irradiation on the electrical properties of n-GaN, AlGaN and AlGN/GaN structures on sapphire substrates. E-beam irradiation resulted in a significant decrease in the gate leakage current of the n-GaN, AlGaN and HEMT structure from 4.0×10<SUP>-4</SUP> A, 6.5×10<SUP>-5</SUP> A, 2.7×10<SUP>-8</SUP> A to 7.7×10<SUP>-5</SUP> A, 7.7×10<SUP>-6</SUP> A, 4.7×10<SUP>-9</SUP> A, respectively, at a drain voltage of -10V. Furthermore, we also investigated the effect of E-beam irradiation on the AlGaN surface in AlGaN/GaN heterostructure high electron mobility transistors(HEMTs). The results showed that the maximum drain current density of the AlGaN/GaN HEMTs with E-beam irradiation was greatly improved, when compared to that of the AlGaN/GaN HEMTs without E-beam irradiation. These results strongly suggest that E-beam irradiation is a promising method to reduce leakage current of AlGaN/GaN HEMTs on sapphire through the neutralization the trap.