Improvement in electrical and 2DEG properties of Al$_{0.26}$Ga$_{0.74}$N|GaN|Si HEMTs

Improving material quality is essential for obtaining a high-power device. Surface trapping effects have been present in all HEMT devices, and have significantly impacted the problem of drain-current collapse. In this paper, performance of intentionally non-doped AlGaN|GaN|Si (HEMTs) before and after passivation with SiO$_2$|SiN is investigated. Capacitance-voltage at various temperatures ($C$–$V$–$T$), a drain current–voltage at various gate voltages $(I_{\mathrm{ds}}-V_{\mathrm{ds}}-V_{\mathrm{gs}})$, the gate leakage current with various temperatures $(I_{\mathrm{gs}}-V_{\mathrm{gs}}-T)$, and the maximum extrinsic transconductance $G_{\operatorname{max}}$ are measured; all of these measurements show the impact of SiO$_2$|SiN passivation on the performances of AlGaN|GaN|Si HEMTs.