Optimizing Threshold Voltage Performance in AlGaN/GaN MIS-HEMTs through GaON Integration

This study investigates electrostatics and current transport in fully recessed gate normally-off AlGaN/GaN MIS-HEMTs with an additional crystalline GaON layer. Self-consistent simulations reveal quantum capacitance vs gate voltage (C-V) characteristics, exhibiting a staircase-like behavior mod-ified by the GaON layer. Variations in channel thickness and doping concentration impact the C-V curve. The 2DEG formation and recessed gate structure's effects on transconductance are discussed, resulting in a positive shift. GaN channel threshold voltage is approximately 0.61 V, increasing to 0.92V with the GaON layer. However, this layer limits the saturation drain current due to lower electron mobility. The influence of GaON thickness on threshold voltage and output characteristics is also explored. These findings provide insights into AlGaN/GaN HEMTs, fostering advanced nanoscale device development.