Current oscillation in GaN-HEMTs with p-GaN islands buried layer for terahertz applications

A GaN-based high electron mobility transistor (HEMT) with p-GaN islands buried layer (PIBL) for terahertz applications is proposed. The introduction of a p-GaN island redistributes the electric field in the gate-drain channel region, thereby promoting the formation of electronic domains in the two-dimensional electron gas (2DEG) channel. The formation and regulation mechanism of the electronic domains in the device are investigated using Silvaco-TCAD software. Simulation results show that the 0.2 mu m gate HEMT with a PIBL structure having a p-GaN island doping concentration (N (p)) of 2.5 x 10(18) cm(-3)-3 x 10(18) cm(-3) can generate stable oscillations up to 344 GHz-400 GHz under the gate-source voltage (V (gs)) of 0.6 V. As the distance (D (p)) between the p-GaN island and the heterojunction interface increases from 5 nm to 15 nm, the fundamental frequency decreases from 377 GHz to 344 GHz, as well as the ratio of oscillation current amplitude of the fundamental component to the average component I (f)/I (avg) ranging from 2.4% to 3.84%.

Automated summary

A GaN-based HEMT with p-GaN island buried layer is proposed for terahertz applications. The redistribution of the electric field in the gate-drain channel region promotes the formation of electronic domains in the 2DEG channel. The simulation results show that the HEMT with a PIBL structure can generate stable oscillations up to 344 GHz-400 GHz.