A Novel E-Mode GaN p-MISFET with Hole Compensation Effect Achieving High Drain Current and Ultra-Low Subthreshold Slope

In this work, a novel enhancement-mode GaN p-MISFET featuring a Buried Back Gate (BBG) is proposed to achieve high drain current density and ultra-low subthreshold slope. With the delicately designed 2DEG back-gate channel on the p-GaN/AIN/AIGaN/AIN/GaN heterostructure platform, both of the p-channel current capability and the gate-to-channel control can be effectively enhanced. Compared to conventional GaN p-MISFETs, the BBG p-MISFET exhibits a significant increase in drain current density from −2.1 to −9.1 rnA/mm and a reduction in subthreshold slope from 148 to −60 mV/dec. The back-gate effect and hole compensation mechanism of the BBG p-MISFET have been thoroughly elucidated through TCAD simulation. Furthermore, mixed-mode simulations were conducted to validate the performance improvement of the basic inverter with the BBG p-MISFET based on monolithic integration, showcasing superior voltage conversion characteristics and dynamic switching behavior. The results suggest the potential applications of the proposed BBG p-MISFET in GaN-on-Si single-chip integrated complementary logic for high frequency and high efficiency GaN ICs.