Roles of Hole Trap on Gate Leakage of p-GaN HEMTs at Cryogenic Temperatures

At cryogenic temperatures,
${p}$
-GaN high- electron-mobility transistors (HEMTs) exhibit a frozen trap effect that causes hole carriers to become trapped in long-lived states, thereby affecting carrier transport. Capacitance deep-level transient spectroscopy (
${C}$
-DLTS) tests and analysis based on theoretical models are conducted to identify the roles of hole trap on gate leakage current. It is found that frozen hole traps would alter the gate leakage mechanism from Poole-Frenkel (PF) emission to trap-assisted tunneling (TAT) at cryogenic temperatures. Understanding the roles of hole trap on gate leakage is crucial for accurately predicting device performance and optimizing performance for cryogenic applications.