Effect of InGaN Channel on Radio‐Frequency Performance in High‐Electron‐Mobility Transistors with an InAlGaN Barrier

Abstract

The effect of the InGaN channel on the performance of high‐electron‐mobility transistors (HEMTs) through the Silvaco Atlas simulator is investigated in detail. It is shown that the 2D electron gas (2DEG) density and carrier confinement of the device can be enhanced by replacing the GaN channel with the InGaN channel. The higher 2DEG density significantly increases the saturation drain current density, thus improving the current drive capability of the device. Meanwhile, better carrier confinement alleviates the short channel effects (SCEs) and traps state‐related current collapse in the GaN buffer, effectively improving the reliability of the device. Better carrier confinement also increases the current gain cutoff frequency (fT) and maximum oscillation frequency (fmax) to 133 and 226 GHz, while the fT and fmax of conventional GaN channel HEMTs are 104 and 167 GHz, respectively. These results indicate that AlInGaN/InGaN HEMTs achieve better performance in direct current (DC) and radio frequency (RF).