First demonstration of a self-aligned p-channel GaN back gate injection transistor

In this study, we present the development of self-aligned p-channel GaN back gate injection transistors (SA-BGITs) that exhibit a high ON-state current. This achievement is primarily attributed to the conductivity modulation effect of the 2-D electron gas (2DEG, the back gate) beneath the 2-D hole gas (2DHG) channel. SA-BGITs with a gate length of 1 μm have achieved an impressive peak drain current (I _D,MAX) of 9.9 mA/mm. The fabricated SA-BGITs also possess a threshold voltage of 0.15 V, an exceptionally minimal threshold hysteresis of 0.2 V, a high switching ratio of 10⁷, and a reduced ON-resistance (R _ON) of 548 Ω·mm. Additionally, the SA-BGITs exhibit a steep sub-threshold swing (SS) of 173 mV/dec, further highlighting their suitability for integration into GaN logic circuits.