Enhanced power performance and threshold voltage stability in quaternary InAlGaN/GaN MIS-HEMTs on Si with gate field plate

This work presents GaN-on-Si metal–insulator–semiconductor high-electron-mobility transistors (MIS-HEMTs) featuring a quaternary InAlGaN barrier and gate field plate (GFP) for power device applications. The proposed device has achieved a 40% increase in drain current and a 21.6% lower ON-resistance (R ON ) compared to conventional AlGaN/GaN HEMTs, due to a high carrier density of ~ 1.9 × 10¹³cm⁻², high mobility of 1540 cm² /V·s. These enhancements yield a low specific ON-resistance (R ON,sp ) of 2.27 m Ω · cm ² . The device also exhibits excellent breakdown performance, with a drain breakdown voltage of ~ 950 V without Gate Field Plate (GFP) and >1500 V with GFP optimized at 4 μ m, enabled by a low sheet resistance (R ₛₕ ) of ~ 215 Ω / . Furthermore, thermal reliability is confirmed by a minimal threshold voltage (V TH ) of ~ 0.4 V and a variation of approximately 20% in maximum drain current (I D,max ) at 150 ∘ C. Moreover, this study attains a state-of-the-art achievement with a tradeoff of a high device figure-of-merit (FOM) on BV DS² /R ON, sp of ~ 1100 MW/cm ² . In addition, we have also carried out the Long-term reliability under positive and negative bias temperature instability (PBTI/NBTI) stress tests under the specific bias of V GS =10 V, V DS =0 V and V GS = -30 V, V DS =0 V, respectively. It reveals that all GFP-equipped devices exhibit smaller V TH shifts under PBTI, while NBTI induces a slightly higher degradation, indicating distinct charge-trapping mechanisms in both processes.