Unique Gate Bias Dependence of Dynamic ON-Resistance in MIS-Gated AlGaN/GaN HEMTs and Its Dependence on Gate Control Over the 2-DEG

This work reports a unique gate bias dependence of dynamic ON-resistance in metal–insulator–semiconductor (MIS)-gated AlGaN/GaN high-electron-mobility transistors (HEMTs). The absence of such dependence in Schottky HEMTs confirms that the phenomenon is unique to MISHEMTs. Based on the observations, the weakening of gate control over GaN channel by the insertion of the gate insulator is proposed as the phenomenon responsible for the observed behavior. The proposal is verified by incorporating high-
$\kappa $
(25)
$\text {Al}_{{0.5}}\text {Ti}_{{0.5}}\text {O}_{y}$
as the gate oxide, which successfully mitigated the gate bias dependence of dynamic ON-resistance by improving the gate control.