A 1.5×10⁹ I_ON/I_OFF Ratio p-channel E-Mode InGaN MESFET with p-GaN/InGaN/AlN Composite-Channel and Tungsten Gate

In this study, a high-performance p-channel enhancement-mode InGaN metal-semiconductor field-effect transistor (MESFET) is demonstrated, featuring an energy-band modulated p-GaN/InGaN/AlN composite-channel and a nano-scaled tungsten (W) Schottky gate. Taking advantage of the quantum well-like InGaN channel for enhanced hole confinement, combined with a nano-scaled gate design and an ideal Schottky gate interface, the device achieves a remarkably low off-state leakage current of 0.97 pA/mm, a record ION/IOFF ratio of 1.5×10⁹, and a steep subthreshold swing of 77 mV/dec. The fabricated p-channel GaN MESFET, featuring a reduced gate-to-drain distance of 0.83 μm, demonstrates a high breakdown voltage of −105 V and a negative threshold voltage of −0.85 V. Meanwhile, owing to the idealized W Schottky gate contacting to p-GaN, an ultra-low hysteresis voltage of 0.03 V is obtained, when subjected to multiple dual sweeps across diverse gate voltage ranges and prolonged stress time.